Search

This work proposes a small circular monopole antenna with reconfigurable dual bandnotch characteristics designed for ultrawideband (UWB) applications. To provide tunable bandnotched characteristics, varactors are stacked in two via fractal (TVF) and mushroom electromagnetic band gap (EBG) structures. The first varactor diode is in the TVF EBG tuning band notch frequency for the WiMAX band (2.8-3.5 GHz). The second varactor diode is situated at the mushroom EBG tuning band notch frequency for the satellite downlink communication (5.9-7.9 GHz) X band. WiMAX and the X-notched band are achieved by varying the tuning of the varactors. Band notch characteristics is constantly reconfigured by adjusting reverse bias voltage across the varactors. The antenna structure is fabricated on FR4 substrate with a size of 24 × 24 mm2 which provides a size reduction of more than 25% with respect to recent literature. Proposed antenna give a large bandwidth (S11< -10 dB) from 2.8 to 12.0 GHz, excluding notched bands. The band notch frequency is continually adjusted from 2.8-3.5 GHz, and 6.0-7.9 GHz by adjusting the capacitance of the varactor diode from 0.487 to 2.35 pF. The simulated and measured results indicate that the proposed antenna is a good candidate. [ABSTRACT FROM AUTHOR]

Summary: A compact and novel ultrawideband (UWB) antenna integrated with Ku band for microwave imaging applications is reported. The reported antenna consists of a novel patch structure along with a tapered feed structure on top of FR‐4 substrate having a compact dimension of 16 × 22 mm2 and novel semicircular defected ground structure (SC‐DGS) etched below the substrate. The proposed antenna covers a wide impedance bandwidth of 15.07 GHz spanning from 3.51 to 18.58 GHz with a fractional bandwidth (FBW) of 136%. The intended antenna performance is analyzed for S11, peak gain, efficiency, and radiation patterns in frequency domain, and group delay, isolation (S21), and linear phase response in time domain. The simulated and measured results of reported antenna are well matched for the usage in practical portable UWB applications. More importantly, the proposed antenna system is simulated for the detection of breast cancer tissue by comparison of S21 results, current densities, and specific absorption rate with and without tumor conditions. These findings show that the radiator and the whole system work well in detecting the breast tumor. [ABSTRACT FROM AUTHOR]

In this work, a compact, edge-fed modified rectangular patch size, monopole, and ultra-wideband antenna has been presented for their good suitability to millimeter (mm) wave and upper sub-6 GHz frequency range (FR2) for next-generation (5G and beyond) communications. The patch size enhancement approach has been utilized without affecting the original size of the substrate and rectangular patch. The technique provides better impedance matching at the designed frequency of 32.5 GHz. The minimum acceptable gain for an antenna to work well is 5 dBi. The proposed design achieves peak gain of 5.43 dBi and 10.86 dBi at two resonance frequencies of 32.5 GHz and 48.12 GHz within the specified ultra-wideband (UWB). The antenna has low loss as it is fabricated on a compact Rogers RT Duroid 5880 of thickness 1.6 mm. The measured reflection coefficients are found in good agreement with the simulated one. The resultant performance parameters like radiation pattern, reflection coefficient, peak gain, and − 10 dB bandwidth reveal that the antenna performs excellently within 26 to 40 GHz with excellent impedance matching at the resonance frequency. At higher frequencies, the time domain response of the proposed design is also presented. The RLC electrical equivalent circuit of the proposed design is presented at the end and validated using ADS software. [ABSTRACT FROM AUTHOR]

This paper presents a novel multi-objective naked mole-rat (MONMR) algorithm to optimize two printed monopole patch antenna structures for ultrawideband (UWB) applications. The design includes basic-ultrawideband and triple band-notch characteristic antennas. The performance of MONMR is evaluated for two objectives: minimize pass-band signal reflection and maximize the gain of the antenna. In resultant, MONMR provided multiple optimum antenna designs instead of a single antenna design by mapping solutions to the Pareto-front (PF) boundary in the objective space. The simulated results matched with the experimental results and hence MONMR has proved to be an effective approach in the field of electromagnetics. Moreover, the obtained PF designs are better than the reported UWB antennas in terms of the gain and reflection coefficient. [ABSTRACT FROM AUTHOR]

Proposal and comprehension of spur line embedded frequency notched Ultrawideband antenna is projected in this paper. The performance of the antenna is enhanced by using square shaped metamaterial. Quarter-wavelength long spur line (lines) on the feeding microstrip line of UWB antenna backs a notch-filtering action to provide single/double/triple notch (notches) within the UWB spectrum of the antenna. The planned method is very simple and radiator independent. The conventional monopole antenna is loaded with square shaped metasurface (MS) to enhance the performance of the antenna. With and without metamaterial loaded single, double and triple spurline embedded microstrip fed circular monopole antennas are separately designed, fabricated and measured. All the deliberate models are fabricated and considered for measurement of impedance and radiation characteristics. Measured results show very good consistency with that of results obtained from full wave simulation. [ABSTRACT FROM AUTHOR]

In this paper, a miniaturized textile microstrip antenna is proposed for wireless body area networks (WBAN). The ultra-wideband (UWB) antenna used a denim substrate to reduce the surface wave losses. The monopole antenna consists of a modified circular radiation patch and an asymmetric defected ground structure, which expands impedance bandwidth (BW) and improves the radiation patterns of the antenna with a small size of 20 × 30 × 1.4 mm3. An impedance BW of 110% (2.85–9.81 GHz) frequency boundaries was observed. Based on the measured results, a peak gain of 3.28 dBi was analyzed at 6 GHz. The SAR values were calculated to observe the radiation effects, and the SAR values obtained from the simulation at 4/6/8 GHz frequencies followed the FCC guideline. Compared to typical wearable miniaturized antennas, the antenna size is reduced by 62.5%. The proposed antenna has good performance and can be integrated on a peaked cap as a wearable antenna for indoor positioning systems. [ABSTRACT FROM AUTHOR]

An ultra-wideband (UWB), geometrically simple, compact, and high-gain antenna with a WLAN notch band is presented for future wireless devices. The antenna is printed on the top side of the Rogers RT/Duroid 5880 substrate and has a small dimension of 10 mm × 15 mm × 0.254 mm. The primary radiator of the proposed coplanar waveguide-fed monopole antenna is comprised of a rectangular-shaped structure initially modified using a slot, and its bandwidth is further enhanced by loading a Y-shaped radiator. As a result, the antenna offers a –10 dB impedance matching bandwidth of 11.55 GHz ranging from 3–14.55 GHz, covering globally allocated C-, S-, and X-band applications. Afterward, another rectangular stub is loaded in the structure to mitigate the WLAN band from the UWB spectrum, and the final antenna offers a notched band spanning from 4.59 to 5.82 GHz. Moreover, to validate the simulated results, a hardware prototype is built and measured, which exhibits good agreement with the simulated results. Furthermore, the proposed work is compared to state-of-the-art antennas for similar applications to demonstrate its design significance, as it has a compact size, wider bandwidth, and stable gain characteristics. [ABSTRACT FROM AUTHOR]

This article presents an ultra-wideband (UWB) monopole antenna with triple band notch characteristics. The proposed antenna consists of an octagonal patch, fed with a 50 Ω line, which occupies a compact size of 40 mm × 29 mm (0.36λ × 0.26λ, λ is computed using 2.7 GHz frequency) and resonances at a relatively low frequency (2.94 GHz). Specifically, an L-shaped stub, an inverted C-shaped slot, and a pair of U-shaped resonating structures are introduced into the design, which allow antenna to generate three band notches at 3.22–3.83 GHz, 4.49–5.05 GHz and 7.49–8.02 GHz, corresponding to WiMAX band, Indian national satellite (INSAT) band, and X-band satellite frequencies, respectively. In the center of the notched band, the antenna has lower efficiency and gain, essentially indicating that the antenna has good interference rejection performance. To evaluate its performance, the proposed antenna has been fabricated and measured, and the relevant functional parameters, such as S-parameters, voltage standing wave ratio (VSWR) and radiation property, have been studied. [ABSTRACT FROM AUTHOR]

This paper discusses an elliptical ultrawideband (UWB) antenna and a dual-band UWB notch antenna. To achieve a UWB bandwidth, two corner cuts are etched into the rectangular slot on the partial ground plane. An inverted-U-shaped and conductor-shaped resonator are utilized to achieve dual-band notch characteristics on a partial ground plane. The suggested antenna has an overall dimension of 24 × 32   mm 2 . The suggested UWB antenna has a gain of 4.9 dB, a bandwidth of 2.5–11 GHz, a linear phase response, a group delay of less than 1 ns, and a steady radiation pattern. The suggested UWB notch rejects WLAN and ITU bands from 5.2–5.7 GHz and 7.2–8.5 GHz, respectively, with an impedance bandwidth of 2.5–11 GHz. The UWB notch antenna features a linear phase, a group delay of less than 1 ns, and a stable radiation pattern. [ABSTRACT FROM AUTHOR]

In this manuscript, a compact in size yet geometrically simple Ultra-Wideband (UWB) antenna is demonstrated. The flexible-by-nature substrate ROGERS 5880, having a thickness of 0.254 mm, is utilized to design the proposed work. The antenna configuration is an excerpt of a traditional rectangular monopole antenna resonating at 5 GHz. Initially, a pair of triangular slots are employed to extend the impedance bandwidth of the antenna. In addition, a semi-circular-shaped, short-ended stub is connected at the upper edges of the patch to further increase the operational bandwidth. After optimization, the proposed antenna offers UWB ranging from 2.73–9.68 GHz, covering almost the entire spectrum allocated globally for UWB applications. Further, the antenna offers a compact size of 15 × 20 mm2 that can easily be integrated into small, flexible electronics. The flexibility analysis is done by bending the antenna on both the x and y axes. The antenna offers performance stability in terms of return loss, radiation pattern, and gain for both conformal and non-conformal conditions. Furthermore, the strong comparison between simulated and measured results for both rigid and bent cases of the antenna, along with the performance comparison with the state-of-the-art, makes it a potential candidate for present and future compact-sized flexible devices. [ABSTRACT FROM AUTHOR]

A compact printed antenna with three rejected bands has been examined and presented in this manuscript. This antenna is fed by a coplanar waveguide and operates over a wide range of frequencies. An arc-shaped, rectangular strip like and split-ring slot have been etched from the designed radiating patch to generate the rejection peaks at Wi-MAX, WLAN and X-band satellite communication. Primarily, the rectangular patch has been considered and further this patch is modified to acquire the UWB frequency spectrum from 3.1 to 10.6 GHz. The overall size of designed antenna is 27 × 27 × 1.6 mm3 which comprises of novel structure of radiating patch and 50Ω CPW feed. After modification the final geometry of radiating patch, proposed antenna divulges the VSWR bandwidth of 11.88 GHz (2.12–14.0 GHz). Further, by introducing different types of slots in the final structure of radiating patch antenna exhibits Wi-MAX (3.16–3.76 GHz), WLAN (5.26–5.87 GHz) and X-band satellite communication (7.30–7.68 GHz) rejected bands. Furthermore, designed UWB antenna embellishes the gain of −7.64 dBi, −4.80 dBi and −4.92 dBi at rejected bands, whereas, the gain of antenna at other frequencies varies between 3.65 and 8.19 dBi. Proposed UWB antenna exemplifies the radiation efficiency variation in 77–98% except notched frequency bands. The radiation pattern and group delay of antenna is also at the acceptable level for existing UWB applications. Lastly, final optimized geometry of antenna with three band notched characteristics is being fabricated and verified for the validation of simulated results. Both the results are related and are found in good agreement with each other and also divulged that proposed antenna is eligible candidate for UWB applications with band rejection characteristics. [ABSTRACT FROM AUTHOR]

This paper presents the design of wideband and high gainFrequency Selective Surface (FSS) loaded antenna for ultra-wideband (UWB) wireless applications requiring high-gain. The antenna consists of a monopole and an FSS reflector. Initially, a conventional rectangular monopole antenna is modified using slot and stub to achieve wide operational bandwidth and size reduction. This modified antenna shows 50% miniaturization compared to a primary rectangular monopole, having a wide impedance bandwidth of 3.6-11.8 GHz. Afterward, an FSS is constructed by the combination of circular and square ring structures. The FSS array consisting of 8×8-unit cells are integrated with the antenna as a reflector to enhance the performance of the proposed miniaturized UWB antenna. The loading of FSS results in an improvement of at least 4 dBi gain in the entire operational bandwidth. Moreover, the antenna's bandwidth is also increased at the lower frequency band due to the presence of the FSS. A prototype of the antenna is fabricated and tested to verify the simulation results. The simulation and measurement results show that the antenna offers a wideband -10 dB impedance bandwidth ranging from 2.55-13GHz with a stable peak gain of 8.6 dBi and retains the radiation pattern stability. [ABSTRACT FROM AUTHOR]

Lantern logo shaped novel design of monopole antennas for ultra – wideband applications have been presented in this manuscript. Initially, the lantern shaped radiating patch with L-shaped stubs and fractional ground plane is designed, which exhibits the maximum impedance bandwidth of 8.09 GHz in the frequency range from 2.51 to 10.60 GHz. Further, by employing the semi – circular notch in the ground plane and antenna reveals improved bandwidth of 8.11 and 5.76 GHz in dual frequency ranges 2.65–10.76 GHz and 11.24–17.00 GHz. The overall dimension of proposed antenna is 30 × 30 × 1.6 mm3 and is designed on low cost FR4 glass epoxy substrate with 1.6 mm thickness and 4.4 dielectric constant. Finally, to increase the impedance bandwidth in the entire frequency range from 1 to 17 GHz, a circular and rectangular – shaped stub is introduced in the radiating patch of final geometry of antenna and designated as proposed antenna – I and II. Impedance bandwidth (S11 < − 10 dB) attained for proposed final antenna – I is 143.93% ranging (2.74–16.81 GHz) and proposed final antenna – II is 143.08% ranging (2.82–17.00 GHz). Numerous performance parameters of both the proposed antennas are investigated, such as, peak realized gain, radiation patterns, radiation efficiency and group delay, which are all in acceptable range for distinct wireless and UWB applications. The designed antennas are fabricated and tested for the authentication of results and juxtaposition of experimental and simulated results of antennas have been made and found in good agreement with each other. [ABSTRACT FROM AUTHOR]

In this communication, the design and analyses of the novel printed ultra wide band ring monopole antenna is presented. The recommended antenna has a pretty small size of 20 x 26 x 1.6 mm³ which is designed on the FR4 dielectric material which has the dielectric constant of 4.4 and loss tangent of 0.02. The general geometry of the radiating part of the antenna is composed of the circular ring. The antenna has a defected ground structure which has the circular corner points. The antenna feed is placed in asymmetrical position with respect to the y-axis as a microstrip line. The findings obtained by examining the general antenna performance criteria are presented in a systematic way. The findings of the research prove that the proposed antenna has some suitable performance parameters at the UWB frequency range. [ABSTRACT FROM AUTHOR]

A compact ultra‐wideband (UWB) printed monopole UWB with dual band‐notched characteristics has been designed and investigated in this manuscript. The Wi‐MAX and wireless local area network (WLAN) band rejection characteristics have been obtained by employing the circular ring and arc‐shaped slot along with rectangular slot in radiating patch. Overall size of proposed UWB antenna is 27 × 27 × 1.6 mm3, which consists of sprocket gear wheel shaped structure as a core radiating patch element and excited by using 50 Ω coplanar waveguide feed. The proposed antenna exhibits the UWB frequency spectrum from 3.1 to 10.6 GHz along with Bluetooth frequency range 2.4–2.48 GHz without disturbing overall dimensions of antenna. Proposed antenna reveals the measured VSWR operating bandwidth of 10.0 GHz in the frequency range from 2.0 to 12.0 GHz along with Wi‐MAX and WLAN rejected bands. Moreover, proposed antenna adorns the measured gain of −8.28 and − 9.98 dBi at rejected frequency bands, whereas, at other frequencies, it changes between 1.5 and 5.0 dBi. The radiation efficiency of proposed UWB antenna varies from 84% to 97% except rejected frequency bands. Group delay and radiation pattern have also been analyzed and found appropriate for the current UWB applications. Finally, the optimized structure of antenna with dual band rejection characteristics has been fabricated and tested for the authentication of simulated results. Both the results are compared and are found in good agreement with each other. [ABSTRACT FROM AUTHOR]

A printed quadruple band-notched ultra-wideband (UWB) antenna characteristic is presented. The designed UWB antenna has a size of 32 mm x 30 mm x 1.6 mm and covers an impedance bandwidth off 2.9-14.5 GHz for the entire frequency band. The entire frequency band maintains voltage standing wave ratio (VSWR) < 2, except at WiMAX (3.1-3.6 GHz), WLAN (4.92-6.12 GHz), downlink of X-band for satellite communication systems (7.5-8.4 GHz), and X-band (10.2-11 GHz). By inserting a pair of L-shaped slots into the radiating element, a H-shaped resonator and rectangular split-ring resonators are closely arranged to the microstrip feed-line, alongside the measured impedance bandwidth of 129%. The fabricated antenna radiation pattern and return loss is presented. [ABSTRACT FROM AUTHOR]

This article proposed a novel compact coplanar waveguide (CPW) fed flexible wideband antenna. The antenna is composed of hexagonal radiation patch, rectangular slots and trapezoid ground. The antenna works in 5.2–41 GHz (154.98% fractional bandwidth) range with a return loss of −10 dB. Based on thin liquid crystal polymer (LCP), the antenna has an overall size of 23.6 mm × 15.4 mm × 0.1 mm. The presented antenna is planned and optimized through High Frequency Structure Simulator (HFSS). The simulated and measured results exhibit good characteristics in terms of reflection coefficients, peak gain, and radiation patterns. The designed antenna can be used in ultra‐wideband (UWB) systems and C‐band (4–8 GHz), WLAN (5.2–5.8 GHz), X‐band (8–12 GHz), Ku‐band (12–18 GHz), K‐band (18–27 GHz), Ka‐band (27–40 GHz), and millimeter wave (MMW). [ABSTRACT FROM AUTHOR]

This article presents a compact multiband, multimode frequency reconfigurable antenna for heterogeneous wireless applications. The antenna features a simple geometrical configuration consisting of a triangular monopole antenna loaded with three stubs. By adjusting the biasing condition of the three embedded diodes, six different operation modes are achieved that are wideband, single narrow band, dual‐band, and triband operational modes. The proposed antenna offers an acceptable gain, omnidirectional radiation pattern, and high efficiency. The antenna prototype was fabricated and tested to validate its performance. The strong agreement between simulated and measured results confirms the suitability of the proposed antenna for modern wireless applications, requiring multiband and multimode compact antennas. [ABSTRACT FROM AUTHOR]

In this article, a microstrip-feed planar monopole ultra-wide band (UWB) antenna is proposed for the chipless RFID (CRFID) tag-reader systems with the intension to reduce the size of the tag. This antenna is keyhole shaped and small in size of 32 × 20 mm² compared with other existing antennas in the retransmission-based chipless CRFID system. The partial ground plane technique is applied here to obtain the bandwidth of 6.81 GHz within the UWB frequency spectrum. The results show it is suitable for both identification and sensing application in the retransmission-based CRFID. The antenna has a good omni-directional radiation pattern with realized gain up to 4 dBi and the realized gain to antenna size ratio goes as high 0.39/cm² which is comparatively higher than the other existing antennas in retransmission-based CRFID. The other feature of this antenna is it has the radiation efficiency up to 99% whereby it never goes below 96% throughout the working bandwidth and the measured antenna efficiency goes as high as 95%. Furthermore, to check the suitability to apply in CRFID sensor application, the proposed antenna has been realized on three flexible substrates of polyimide, PET and paper, and very little deviations are found compared to the rigid Rogers RT 3003 substrate in terms of S11, realized gain, efficiency and radiation pattern which is a proof of robustness of the design. This proposed antenna will motivate the researcher to develop a smaller sized UWB CRFID tags. [ABSTRACT FROM AUTHOR]

In this paper, CPW-Fed ultra wideband (UWB) planar monopole antenna loaded by double inclined elliptical split ring resonators (ESRRs) for double band-notch characteristics is introduced, examined, and fabricated. Two different ESRRs with different dimensions are printed in the antenna backside to notch two different frequencies in the UWB frequency range instead of using two ESRR pairs as usual. The ESRRs are then rotated and the corresponding return loss is studied. Different notch frequencies can be obtained by varying the ESRRs' dimensions. Finite element method FEM and finite integration technique FIT are used to simulate the proposed structures through the usage of Ansys HFSS and CST MWS. Good agreement between both results has been obtained. Two different prototypes of the proposed antenna are fabricated and their reflection characteristics are measured. The first antenna is the UWB antenna with two straight ESRRs in which two notch frequencies at 5.3 GHz and 6.8 GHz have been obtained. The second antenna is the UWB antenna with two inclined ESRRs in which two notch frequencies at 5.1 GHz and 6.9 GHz have been obtained. In both cases, good agreement between simulated and measured results has been obtained and the discrepancies are due to fabrication and alignment errors. Also in both cases the proposed antennas notch WLAN and C-band wireless coexisted applications. A directive radiation pattern in E-plane and omnidirectional radiation patterns in the H-plane could be observed. Also the gain is suppressed in the notch frequencies in both cases. The group delay is nearly stable in the UWB frequency range, except at the notch frequencies, which is distorted sharply. So, the proposed antenna is a good candidate for the modern UWB systems. [ABSTRACT FROM AUTHOR]

In this paper, application of a designed antenna for microwave imaging is evaluated. In previous research, application of an UWB antenna for microwave imaging was investigated. To the best of the author's knowledge, the designed antenna was the smallest UWB antenna designed at the time of publication, for breast cancer detection. The smaller size antennas can cause more clutter in the image while, on the other hand, make it possible to use more antennas in the array at the same surface. Therefore, the smaller size of the antenna makes microwave imaging more challenging. Simulation results showed successful detection of 10 mm and 5 mm tumors by 16 UWB antennas with the hemispherical arrangement. For signal processing, the Delay-Multiply-and-Sum Algorithm is used for image reconstruction. In this paper results of two experimental microwave imaging is presented. Two tumors at different locations are placed and microwave imaging is performed. The experimental proves that the designed antenna in an array of 16 antennas is capable of detecting the 5 mm tumor in different location. [ABSTRACT FROM AUTHOR]

Compact coplanar waveguide Ultra-wideband (UWB) monopole antenna with band notched characteristics is presented in this paper. The band rejection is achieved by etching a circular slot on the radiating patch. The antenna is printed on the FR4-Epoxy substrate with overall dimensions of 23.5 x 31 x 1.5 mm³. The measured results indicate that the antenna operates in the frequency range from 1.76 to 11.07 GHz and rejects the band 2.42 to 5.37 GHz with an acceptable measured input impedance over the whole operating frequency bandwidth. Furthermore, the simulated results indicate that the antenna exhibits stable radiation patterns with appreciable gain and efficiency over the whole operating band except at the notched-band. Accordingly, this antenna provides a good solution for wireless communication systems with good characteristics. [ABSTRACT FROM AUTHOR]

This article presents the design of an ultra‐wideband (UWB) quasi‐circular monopole antenna with directional characteristics for use in wireless body area network (WBAN) applications. The proposed antenna has hybrid geometry and it is constructed using a semicircular and square patch on a very thin substrate of thickness 0.2 mm. The antenna has a compact geometry with a footprint of 30 × 20 mm. The proposed antenna covers 3.1 to 10.6 GHz with a measured peak gain of 5.37 dBi at 6 GHz. The proximity effect of the human body is resolved by incorporating the reflector behind the antenna. The antenna with reflector provides a directional pattern with a measured peak gain of 8.84 dBi at 6 GHz. Further to improve the link reliability between the sensor and the cluster head in WBAN, polarization diversity technique is adopted and the performance metrics are evaluated. The proposed flexible antenna simultaneously offers large gain and high impedance bandwidth. The prototype antenna is fabricated and the simulation results are validated using experimental measurements. The measurement results are in good agreement with the simulation results. [ABSTRACT FROM AUTHOR]

A modified rectangular monopole ultra-wideband (UWB) antenna with penta notched frequency bands is presented. An inverted U shaped and slanted U-shaped on the radiating patch are inserted to achieve WiMAX and ARN bands rejection respectively, two mirrored summation Σ-shaped and four mirrored 5-shaped slots are inserted on the partial ground to achieve WLAN and X-band bands rejection respectively, finally rectangular shaped slot with partially open on the feed is inserted to achieve ITU-8 band rejection. The proposed antenna which was simulated has a compact size 30×35×1.6 m3. It is operated with impedance bandwidth 2.8-10.6 GHz at ∣S11∣ < -10 dB, that supported UWB bandwidth with filtering the five narrowbands that avoid the possible interference with them. The simulated resonant frequency for notched filters received 3.55, 4.55, 5.53, 7.45, 8.16 GHZ, for WiMAX, ARN, WLAN, X-Band, ITU-8 respectively. The proposed antenna is suitable for wireless communication such as mobile communication and internet of everything (IoE). Throughout this paper, CST-EM software package was used for the design implementation. Surface current distributions for all notched filters were investigated and shown that it is concentrated around the feeding point and the inserted notched slots proving that there is no radiation to the space due to maximum stored electromagnetic energy around each investigated notch slot, proving that the slots play a role of a quarter wavelength transformer which generates for each notched band, maximum gain, and radiation pattern are also investigated. [ABSTRACT FROM AUTHOR]

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper proposed quadruple notched frequency bands ultra-wideband (UWB) antenna. The antenna is a semicircular-shaped monopole type of a compact size 36x24 mm, covering frequency range of 3.02-14 GHz. Four rejected narrow bands including WiMAX (3.3-3.7GHz), ARN (4.2-4.5 GHz), WLAN (5.15-5.825GHz), X-Band (7.25-7.75) have been achieved using inserting slots techniques in the patch, feed line, and ground plane. The slots dimensions have been optimized for the required reject bands. The antenna design and analysis have been investigated by simulation study using CST-EM software package. The antenna characteristics including impedance bandwidth, surface current, gain, radiation efficiency, radiation pattern have been discussed. [ABSTRACT FROM AUTHOR]

An ultra wideband (UWB) antenna fed through a flangeless standard SMA connector near one of the vertices of hexagonal patch is introduced here, in this paper. The designed antenna possess a half elliptical but truncated ground plane with a rectangular slot to achieve UWB with monopole radiation characteristics. The antenna prototype provides an impedance bandwidth of 8.3 GHz from 2.3 to 10.6 GHz with a WLAN band rejection of 1.6 GHz from 4.9 to 6.5 GHz. Antenna measurements show that removal of flanges modifies a C-band antenna to an UWB antenna. The demonstrated technique can be utilized to achieve ultra wideband in probe fed antenna. Measurement results match the expectations as predicted by simulation results. [ABSTRACT FROM AUTHOR]

In this paper, we present the analysis of a novel monopole antenna with a reflector. The proposed monopole antenna is printed on a TRF-45 substrate, and the reflector, which is positioned near the base of the antenna, is printed on the FR-4 substrate. Positioning the reflector near the base of the antenna was found to suppress current radiation toward the back of the monopole antenna. Comparative analysis of the proposed monopole antenna and a conventional monopole antenna without a reflector revealed that the bandwidths of the antenna with and without a reflector were 2.65 GHz and 2.88 GHz, respectively. Additionally, the antenna without a reflector was observed to have a bi-directional radiation pattern in the E-plane, and an omni-directional radiation pattern in the H-plane. However, only the antenna with a reflector was found to suppress back radiation, and provide non-uniform directional radiation in the E-plane and H-plane. [ABSTRACT FROM AUTHOR]

In this paper, a new approach to the design of an UWB monopole antenna with dual band-notched characteristics is presented. The antenna has the form of an elliptical monopole over a ground plane having an elliptical slot to achieve the UWB. The dual-band notch function is created by inserting a U-shaped and a C-shaped slots on the radiating patch, thus no extra size is needed. The proposed antenna shows a good omnidirectional radiation pattern across the band from 3.2 to more than 14 GHz. The dual band-rejection is for 4.88-5.79GHz centered at 5.4GHz and 7.21-8.46 GHz centered at 7.8 GHz. The antenna prototype using the FR-4 substrate with er=4.3 has a compact size of 25mm×25 mm ×1.45mm. The fabricated prototype showed experimental results comparable to those obtained from the simulations. [ABSTRACT FROM AUTHOR]

A defected ground structure‐based rectangular monopole antenna along with 2 × 2 and 4 × 4 multiple‐input multiple‐output (MIMO) antennas are presented. The proposed monopole antenna consists of a defected ground structure with two slits and a notch placed at optimum positions to increase the impedance bandwidth. Besides, the radiator is loaded with a U‐shape stub to improve the impedance matching of the antenna. The measured impedance bandwidth of the proposed monopole antenna is from 3.18 to 11.5 GHz. Time domain experiment is carried on to investigate the dispersion characteristics of the proposed antenna. Measurement results reveal that the proposed antenna can retain the transmitted pulse shape, ensuring dispersion‐free communication. Far‐field measurements confirm omnidirectional radiation patterns over the operating bandwidth. Moreover, MIMO performance of the proposed 2 × 2 and 4 × 4 antenna arrays are evaluated based on isolation, envelop correlation coefficient, diversity gain, and channel capacity loss. The proposed single monopole and MIMO versions of this antenna can be used in portable UWB communication devices. [ABSTRACT FROM AUTHOR]

The paper proposes a MIMO antenna composed of two elements in the form of UWB monopole antennas. Polarization diversity of the proposed antenna is obtained locating the two elements perpendicularly on a common substrate. Also the isolation between elements is accomplished without using any extra decoupling structures. The two monopoles antennas with half elliptical shape are fed with asymmetric coplanar strip (ACS). The presented antenna is located on substrate 48 x 28 mm² in total size. The distance between the two elements is 15 mm that is 0.15λ0 at 3GHz. The antenna was designed to work effectively from 3 to 11.5 GHz with reflection coefficient better than -10 dB and isolation lower than 18 dB. In addition, antenna with elements located in parallel was designed to show the advantage of the original design. Envelope correlation coefficient, diversity gain and channel capacity loss document the antennas behavior. The antenna was fabricated and measured. Measurement validated the simulation and showed that the designed antenna can be well applied in UWB MIMO systems. [ABSTRACT FROM AUTHOR]

This communication presents the design, fabrication, and testing of a tunable band-notched UWB filtering antenna. The proposed filtering antenna comprises a semiellipsoid radiator and a microstrip transmission line to cover the UWB communication bandwidth from 3.1 to 10.6 GHz. It also comprises two J-shaped open-ended stubs and an asymmetric T-shaped open-ended stub to create notch bands at 3.5 GHz (WiMAX), 5.2 GHz, and 5.8 GHz (WLAN) in the UWB spectrum. The center frequencies of the notch band are tuned continuously using varactors with percentage tuning of 7.5%, 5.38%, and 3.54%. The prototype is fabricated and experimentally validated. [ABSTRACT FROM AUTHOR]

In this paper, a compact superformula ultra‐wideband (UWB) monopole antenna with dual band notches is proposed. The developed structure achieves UWB performance as well as a compact size of 20 × 26 × 1.62 mm3. Furthermore, to avoid interferences with WiMAX and satellite communication systems, dual notched band is obtained by engraving two co‐directional triangular split ring defects on the radiating element. The simulated and measured results show that the proposed antenna has an impedance bandwidth extending from 3.05 to 20 GHz with dual notched bands at [5.15‐5.68 GHz], and [7.15‐7.65 GHz] used in WiMAX and satellite communication, respectively. The proposed design realizes omnidirectional radiation pattern in H‐plane, and a dipole‐like pattern in E‐plane. The antenna exhibits an acceptable gain in the whole UWB range except at notched bands. [ABSTRACT FROM AUTHOR]

In this paper, a compact ultra-wideband (UWB) monopole antenna with triple band-notched characteristics is presented. These triple band rejections are produced by inserting the Complementary Co-directional Split-Ring Resonator (CC.SRR) on the radiating element for WiMAX/WLAN (3.4–3.95 GHz/5.35–5.9 GHz) and Electromagnetic Band Gap (EBG) structure in the vicinity of transmission line for X-band satellite communications (6.7–7.7 GHz). The proposed antenna with a total size of 18×20.9×1.63 mm3 has been constructed and tested. An equivalent RLC circuit model is proposed and investigated. The simulated and measured results show that the proposed antenna has an impedance bandwidth (VSWR<2) extanding from 3.05 GHz to 14 GHz with triple notched bands of [3.3–3.9 GHz], [5.25–5.86 GHz] and [6.7–7.7 GHz]. The triple band notched characteristics and the good radiation patterns make the proposed antenna a good candidate for the UWB applications. [ABSTRACT FROM AUTHOR]

This article presents a compact four-element MIMO antenna for WLAN/LTE/UWB applications. The half-slot structure and half-cut monopole antenna technique are adopted to realize bandwidth from 2 GHz to 10.6 GHz while maintaining good isolation better than 15 dB and compact size of 31 × 31 × 1.6 mm. Each antenna element is composed of a quasi-semi-ellipse radiator and a protuberant ground. To be practical in a real application scenario, four antenna elements with interconnected/common ground are placed orthogonal to each other for good isolation. Key parameters affecting the antenna performance are investigated and a prototype of the proposed antenna is fabricated for measurement. The simulated and measured results agree well, testifying the proposed four-element MIMO antenna is a suitable candidate for WLAN/LTE/UWB applications. [ABSTRACT FROM AUTHOR]

Abstract: In this article, a novel monopole antenna for the ground penetrating radar applications is proposed. The antenna is a monopole bowtie with two slots and a defected ground plane, in order to improve the bandwidth. The proposed antenna shows a great bandwidth from 3.9 to 18 GHz which makes it to be an ultra‐wideband antenna. The overall size of the antenna is 14 × 22 × 1.6 mm3 on the FR4 substrate. Also, a prototype of the proposed antenna is fabricated. The measurement and simulation results are in good agreement. [ABSTRACT FROM AUTHOR]

In this paper a novel band notch antenna in UWB frequency range is designed using split rings. Split rings are overlapped with designed monopole to give phi shape. The slit gap gives band-notch operation from 5.1GHz to 6.29GHz and from 4.94GHz to 5.91GHz for SPSSR and SPSCR antennas respectively. Simulated and measured results are in good agreement. [ABSTRACT FROM AUTHOR]

A new miniaturized ultra-wideband (UWB) monopole antenna with a broad band, sharp roll-off frequency notch function is presented. A narrow, stepped impedance strip is the radiating element of the antenna similar to conventional narrowband antennas, in order to retain the conventional antenna characteristics such as polarization purity, omnidirectional radiation pattern, etc. The strip is split to create multiple closed resonances and inductors are loaded in series to achieve wide bandwidth. The split portions are inserted one over the other to make the antenna very compact. A new compact dual mode wide band parasitic resonator placed along the feed line, rejects the frequency band ranging from 5.15 to 5.825 GHz which has been allocated for IEEE 802.11a and High Performance Radio Local Area Network (HIPERLAN). The designed antenna was fabricated and the results were measured in an anechoic chamber. The measured results show the ultra-wideband resonance with reflection coefficient values below −10 dB over 3–10.5 GHz with a sharp roll off notch band. [ABSTRACT FROM AUTHOR]

This paper presents a compact wideband rectifier system for wireless energy harvesting. The presented rectifier system is completed in two stages. In the first stage, a crescent-shaped wideband circularly polarized antenna (CPA) is designed to receive and transmit RF signals using characteristic mode analysis (CMA). And the CPA consists of a monopole antenna at the top and a slot antenna at the bottom, which control the higher and lower operating bands, respectively. In the second stage, a wideband rectifier is designed using a HSMS-2860 Schottky diode and a three-stage matching network. The HSMS-2860 Schottky diodes improve rectification efficiency at medium-power density, and the three-stage matching network effectively increase the operating bandwidth, filter out the output RF signal, and cancel out and stabilizes the impedance. To validate the proposed rectifier system, a crescent-shaped CP receiving antenna and a rectifier operating in C-band are fabricated, and the rectification performance is measured. The measurement results indicate that the proposed rectifier system harvests RF signals on the broadside and backside of the CPA over a wide input power range (8–13 dBm input power). [ABSTRACT FROM AUTHOR]

In this paper key shaped monopole antenna with and without rectangular slot inserted on feeding strip is proposed for Ultra Wide Band (UWB). This UWB antenna is etched on a 30 x 30mm² commercially available low cost substrate of Flame Recorded Grade 4 (FR4) with thickness of 1.6mm, relative dielectric constant e = 4.4 and dielectric loss tangent = 0.02. One of the industry leading 3D EM software tools for radio frequency (RF) application known as High Frequency Structure Simulator (HFSS) was used to design this UWB antenna. The reflection coefficient Sn of the proposed antenna was found to be less than -10dB and Voltage Standing Wave Ratio (VSWR) is less than 2. It was found that the designed UWB antenna is operable over the entire 3.1GHz - 10.6GHz frequency range. [ABSTRACT FROM AUTHOR]

This communication presents a new reconfigurable filtering monopole antenna design with three switchable states for UWB/WLAN applications. The antenna has three independent ports for ultra-wideband state, 2.4 GHz WLAN narrowband state, and 5.8 GHz WLAN narrowband state, respectively. The narrowband state at 2.4 GHz is produced by a first-order microstrip filter using an open-loop resonator, and the narrowband state around 5.8 GHz is obtained by involving a third-order hairpin bandpass filter in the RF path. Frequency reconfiguration is achieved by RF path selection using dc controlled p-i-n diodes. As a result, narrowband filtering responses at desired frequency bands can be achieved. One antenna prototype is simulated, fabricated, and measured. Measured reflection coefficients and radiation patterns demonstrate that the proposed reconfigurable filtering antenna is an eligible candidate for future multifunctional systems incorporating both UWB and WLAN systems. [ABSTRACT FROM AUTHOR]

In this article a microstrip-fed mickey shaped monopole antenna with triple notched band characteristics for ultra-wideband applications is presented. By etching two slots in the ground plane, improved VSWR bandwidth is achieved. Mickey shape radiating patch provides 10 dB return-loss bandwidth from 3.10 to 10.60 GHz. By etching three simple C-shaped slots on the radiating patch, three existing wireless communication systems which interfere with UWB band is removed which includes WiMAX IEEE802.16 (3.30-3.80 GHz), WLAN IEEE802.11a/h/j/n (5.15-5.35, 5.25-5.35, 5.47-5.725, 5.725-5.825 GHz) and X-band downlink satellite system (7.1-7.9 GHz). Experimental results reveal that the proposed antenna exhibits desirable radiation patterns in the far field, resulting omnidirectional like pattern in the H-plane and nearly dipole like pattern in the E-plane. [ABSTRACT FROM AUTHOR]

In this paper, small printed flower-shape triple notch ultra-wideband (UWB) monopole antenna with high band rejection is presented. Notch bands include WiMAX (IEEE802.16 3.30-3.80 GHz), WLAN IEEE802.11a/h/j/n (5.15-5.35, 5.25-5.35, 5.47-5.725, 5.725-5.825 GHz), and X-band downlink satellite system (7.1-7.9 GHz). By including inverted T-shape stub and etching two C-shaped slots on the radiating patch, triple band-notch function is obtained with measured high band rejection (VSWR = 14.52 at 3.58 GHz, VSWR = 15.88 at 5.69 GHz and VSWR = 6.95 at 7.61 GHz) and covers a UWB useable fractional bandwidth of 114.30% (2.74-10.57 GHz = 7.83 GHz). In short the antenna offers triple band-notch UWB systems as a compact multifunctional antenna to reduce the number of antennas installed in wireless devices for accessing multiple wireless networks with wide radiation pattern. The proposed antenna has a small size of about 0.25λ × 0.30λ at 4.2 GHz (first resonance frequency), which has a size reduction of 30% with respect to the earlier published antenna. Both the experimental and simulated results of the proposed antenna are presented, indicating that the antenna is a good candidate for various UWB applications. [ABSTRACT FROM AUTHOR]

In this research article, a compact (12 × 20 mm) triangular shaped monopole dual-band antenna is presented for 2.4 GHz Bluetooth/WLAN and ultrawideband (UWB) applications. The proposed geometry consist of a simple triangular shaped radiating patch for achieving UWB characteristics and a quarter wavelength inverted L shaped strip attached to the patch for achieving second operating band at 2.45 GHz for Bluetooth/WLAN applications. The first operating band characteristics can be controlled by changing the electrical length of the strip. To enhance the impedance bandwidth of second operating band, an equilateral triangular shaped cut has been introduced in the patch. The measured results (S ≤ −10 dB) demonstrates that the proposed antenna exhibit dual frequency operation from 2.4 to 2.52 GHz (Bandwidth of 120 MHz) and from 3.2 to 10.6 GHz (Bandwidth of 7.4 GHz). The proposed very small dual-band antenna has omnidirectional radiation patterns, peak gains and radiation efficiencies across both the operating bands. [ABSTRACT FROM AUTHOR]

In this article, a planar ring monopole UWB antenna with two kinds of resonators are presented and investigated. The half wavelength opening resonator and quarter wavelength shorting resonator are coupled with the feed line capacitive to obtain notched characteristic. The contrast of current distribution demonstrates this novel method, and experimental results show that the proposed antennas meet the requirement of ultra-wide bandwidth (3.1-10.6 GHz), while avoiding the interference from WLAN band. Some important models and parameters, such as the transmission line model, equivalent circuit model, VSWR, radiation pattern antenna gain, and transfer function are also studied to evaluate notched characteristics. [ABSTRACT FROM AUTHOR]

ABSTRACT A coplanar waveguide (CPW) fed ultra-wideband antenna is proposed for UWB applications. The proposed antenna consists of circular monopole with single complementary split ring resonator (CSRR) slot and reduced ground plane. The overall size of an antenna is 20 × 25 × 1.6 mm3. The prototype antenna is designed, fabricated and tested. It provides good return loss characteristics and radiation pattern. The measured −10 dB impedance bandwidths are 1.06 GHz (3.9-4.96 GHz) and 4.5 GHz (6.7-11.2 GHz) with resonance frequencies at 4.4 and 9 GHz, respectively. An appropriate dimension of CSRR slot has been etched on patch to notch 5-6 GHz band to avoid interference with WLAN and WiMAX devices which is one of the crucial issues to be solved in UWB antenna. Parametric studies on width of ground plane and dimension of CSRR slot are done to investigate the effect of various geometrical values on antenna characteristics. The simulated and measured results of the antenna are in close agreement with each other which will confirm the applicability of the proposed antenna. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:745-749, 2017 [ABSTRACT FROM AUTHOR]

ABSTRACT In this article, a combination of an elliptical UWB monopole with a series of Sierpinski triangle iterations inscribed in the planarized radiator is used to develop a highly-impedance stability UWB antenna, performing from 700 MHz to 9 GHz. The fractal iteration is introduced in order to obtain a radiator size reduction and to improve the current distribution stability. With this implementation, a 31% radiator area reduction is obtained compared to a conventional circular or elliptical radiator. The antenna impedance matching is maintained over the entire bandwidth, even when an external lossy dielectric body is around or even in contact to the radiator. The antenna presents quasi-omnidirectional radiation patterns and a gain around 0 dBi and group delay variations lower than 2 ns, making it suitable for short-pulse communications systems and on-body communications applications. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:635-641, 2017 [ABSTRACT FROM AUTHOR]

A simple quadruple band-notched ultra-wideband (UWB) antenna is proposed and its performance is investigated both numerically and experimentally. The proposed quadruple band-notched UWB antenna is realized based on an asymmetric planar monopole antenna which consists of a fan-shaped radiation patch, a microstrip feeding line and a trapezoidal ground plane. By etching an arc-shaped slot with a gap and adding a rotated E-shaped resonator beside the microstrip feeding line, four notched bands are achieved to suppress potential interferences from WiMAX (3.3-3.6 GHz), WLAN (5.15-5.35 GHz, 5.725-5.825 GHz) and uplink of X-band satellite communication system (7.9-8.4 GHz). The proposed monopole antenna can operate over 2.94-12 GHz band with VSWR<2 except these notch bands. Simulation and measurement results of the fabricated prototype demonstrate that the proposed antenna has quadruple band-notched characteristics and nearomnidirectional radiation patterns, making it suitable for UWB communication applications. [ABSTRACT FROM AUTHOR]

A compact microstrip-fed printed monopole ultra-wideband (UWB) antenna with WiMAX band notched characteristic suitable for UWB applications is proposed. The proposed antenna configuration consists of a beveled ground with U-slot embedded on the radiation patch for realizing the band notch characteristic. The measured results reveal that the fabricated antenna exhibits an impedance bandwidth from 2.96 to 11GHz for a VSWR < 2 with a rejection bands at 3.38-3.92 GHz for WiMAX. Compared to other antennas presented in the literature, the proposed candidate is a quite simple to make the band notched characteristic to reduce the effect of electromagnetic interference. The band rejection function is confirmed by the gain diminishes occurring at 3.69GHz and stable gain outside the rejection band. Surface current distribution is also examined to verify the band rejection property. Investigations on the group delay ensure that the designed antenna has good transmission capability of UWB signal with minimum distortion. [ABSTRACT FROM AUTHOR]