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This paper presents the design and analysis of a miniaturized dual L-shaped inverted to each other dual-band monopole antenna intended for 5G and wireless communication applications. The proposed antenna, with compact dimensions of 20×20×1.6 mm², operates in two frequency bands (3.2-3.6 GHz)/3.5GHz and (6.0-6.6 GHz)/6.5GHz. These frequency bands are critical for 5G technology, ensuring high-speed data transfer and improved network efficiency. The antenna achieves bandwidths of 11.7% and 9.3% for the lower and upper bands, respectively, offering robust performance and adaptability in diverse wireless communication scenarios. The design employs a dual L shape inverted to each other configuration with truncated L shaped ground plane to achieve the desired miniaturization and dual-band functionality. The antenna's performance metrics, including return loss, gain, and radiation patterns, demonstrate its suitability for integration into compact wireless devices, thereby advancing the development of efficient and space-saving 5G communication systems. [ABSTRACT FROM AUTHOR]

This research work addresses the challenges associated with isolation techniques in MIMO antenna design. The proposed 4-port L-Slotted Ultra-wideband (UWB) Multiple-Input Multiple-Output (MIMO) antenna design aims to offer a simple and compact solution that naturally ensures isolation between antenna elements. By employing innovative design strategies, notably incorporating L-Slotted structures, the research aims to extend the impedance bandwidth to 14.28 GHz, with a notch band covering the X-band and the lower portion of the Ku-band. The antenna's performance is evaluated by examining key metrics such as reflection coefficient (< – 10 dB), isolation (< – 20 dB), and diversity parameters. The proposed antenna achieved notable maximum |S11| of 22.77 dB at 6.945 GHz, a peak gain of 10.61 dBi, ECC < 0.0044, TARC < – 10 dB, and a diversity gain of approximately 9.999 dB. The wide impedance bandwidth and compatibility with various frequency bands make this antenna design adaptable to diverse applications and environments, providing flexibility for different system requirements. With its compact and efficient design, this antenna can be integrated into Internet of Things (IoT) devices and smart appliances, enabling reliable and high-speed wireless connectivity. Wide impedance bandwidth makes this antenna design suitable for various wireless communication applications, including Wi-Fi, 5G, and beyond. [ABSTRACT FROM AUTHOR]

An analytical model of metasurfaces made of a rectangular array deposited on a low thickness (10-150 µm) grounded dielectric layer is presented. The surface impedance and the equivalent circuit are extracted from full wave simulations. Contrary to previous works on higher thickness metasurfaces, the absorption corresponds to the first resonance under the patch. The equivalent circuit is made of a parallel resonant RLC circuit in series with an inductance Ls. The analytical expressions of the RLC components and of the quality factors are established from the study of the influence of the different parameters. The inductance Ls is attributed to the non-metallized part of the mesh. The impedance of the resonant circuit expresses as the product of a proportionality factor, the impedance of a single patch and a periodicity factor. The model is validated on different examples. Specific properties are evidenced like the quasi-independence of the equivalent circuit resistance versus the length of the patch, the total absorption condition and the extension of the model to a two patches metasurfaces. Giving a better understanding of the role of the different parameters, the model is useful in view of new applications development notably electrically driven tunable metasurfaces.

We present the results of an efficient analysis–based on adaptive network fuzzy inference systems (ANFIS)–of the impedance an infinite array of rectangular microstrip antennas. In the proposed modeling approach, first, a number of input–output pairs (inputs include spacing between antennas, outputs include resonant frequency, quality factor, and input resistance) are computed from full-wave methods, and they are then used in the training process. An advantage of the proposed model in comparison with full-wave and approximate methods is that, after convergence of the training process, it bypasses the repeated use of complex computations for new inputs presented to it without any restriction. In addition, a comparison of the proposed model with those related to a single rectangular microstrip antenna shows considerable differences, especially for input resistance and quality factor, which is of importance in practical applications. [ABSTRACT FROM AUTHOR]

With the increase in demand for high data rates and high bandwidth because of multiple users all over the globe, the technology has moved toward the next-generation of wireless communication. This rapid advancement of wireless communication technologies has led to the emergence of 5G networks, which promise significantly higher data rates, lower latency, and enhanced connectivity. Researchers believe that five essential techniques can enable 5G. Beamforming is one of those essentials, as it plays a vital role in achieving reliable and high-capacity communication. This review article portrays a comprehensive analysis of the 5G beam-former Microstrip Patch Antenna array techniques for communication systems. The paper comprises of a deep overview of the fundamental concepts and principles of beamforming, including analog, hybrid, and digital beamforming techniques. It explores the advantages and disadvantages of each approach and discusses their suitability for 5G applications. An in-depth examination of various beamforming techniques employed in 5G, encompassing traditional beamforming, massive Multiple- Input-Multiple-Output beamforming, hybrid beamforming, and adaptive beamforming. The discussion encompasses the strengths, weaknesses, and performance trade-offs of each technique, along with their applicability in diverse deployment scenarios and applications. The review of multiple couplers that are used for the feeding of the antenna is discussed with included hybrid coupler, Wilkinson power divider, branch line coupler, and butler matrix in beamformer smart antenna for 5G/6G communications. Numerous beamforming techniques are compared based on their merits, demerits, and applications. Moreover, the dielectric substrate utilized to design the beamformer was also reviewed. The findings presented in this paper serve as a valuable resource for the researcher, scholars, and engineers working in the field of 5G wireless communications and antenna designing, facilitating the development and deployment of efficient and robust beamforming solutions for future 5G networks. [ABSTRACT FROM AUTHOR]

With the increase in demand for high data rates and high bandwidth because of multiple users all over the globe, the technology has moved toward the next-generation of wireless communication. This rapid advancement of wireless communication technologies has led to the emergence of 5G networks, which promise significantly higher data rates, lower latency, and enhanced connectivity. Researchers believe that five essential techniques can enable 5G. Beamforming is one of those essentials, as it plays a vital role in achieving reliable and high-capacity communication. This review article portrays a comprehensive analysis of the 5G beamformer Microstrip Patch Antenna array techniques for communication systems. The paper comprises of a deep overview of the fundamental concepts and principles of beamforming, including analog, hybrid, and digital beamforming techniques. It explores the advantages and disadvantages of each approach and discusses their suitability for 5G applications. An in-depth examination of various beamforming techniques employed in 5G, encompassing traditional beamforming, massive Multiple-Input-Multiple-Output beamforming, hybrid beamforming, and adaptive beamforming. The discussion encompasses the strengths, weaknesses, and performance trade-offs of each technique, along with their applicability in diverse deployment scenarios and applications. The review of multiple couplers that are used for the feeding of the antenna is discussed with included hybrid coupler, Wilkinson power divider, branch line coupler, and butler matrix in beamformer smart antenna for 5G/6G communications. Numerous beamforming techniques are compared based on their merits, demerits, and applications. Moreover, the dielectric substrate utilized to design the beamformer was also reviewed. The findings presented in this paper serve as a valuable resource for the researcher, scholars, and engineers working in the field of 5G wireless communications and antenna designing, facilitating the development and deployment of efficient and robust beamforming solutions for future 5G networks.

A dual-band Multiple Input Multiple Output (MIMO) antenna with low mutual coupling is analyzed and studied for Fifth Generation (5G) Sub-6 GHz and Wireless Fidelity (Wi-Fi) 6E frequency-band applications. Each of the identical monopole radiators consists of a rectangular patch, inverted-E, and asymmetrical T-shaped strip to generate 5G Sub-6 GHz and Wi-Fi 6E frequency bands. The deployment of the radiators horizontally with end-to-end separation of 5mm makes the antenna compact with an overall dimension of $45\times 30$ mm2 ( $0.37\lambda \times 0.25\lambda $ for $\lambda $ at the lower resonating frequency of 2.5GHz). The antenna achieves measured impedance bandwidths of 2.39-2.57 GHz and 3.82-6.95 GHz, respectively, at two resonating frequencies of 2.5 GHz and 4.5 GHz. A Parasitic Dollar Shaped Structure (PDSS) introduced between the two monopole radiators to suppress the surface waves of each monopole reduces the measured mutual coupling up to -15 dB throughout the operating band. Furthermore, the measured gain, radiation efficiency, Envelope Correlation Coefficient (ECC), and Diversity Gain (DG) values remain in good agreement with simulated values and are well within the minimum limit set by industry standards. These results affirm the applicability of the MIMO antenna for 5G and Wi-Fi 6E frequency bands.

A monopole rectangular shape patch antenna (RSPA) with trapezoidal shape complementary split ring resonator (CSRR) is designed for wireless communication application is presented in this paper. The trapezoidal shape CSRR is considered to obtain circular polarization and rectangular slit is considered to operate antenna for triple frequencies at 1.88, 4.17, and 6.73 GHz, respectively. The axial ratio of 1.25, 1.05, 1.28 dB is observed and a maximum gain of 6.29 dBi at 1.88 GHz frequency is produced. The RSPA model is designed for mobile and fixed satellite application. [ABSTRACT FROM AUTHOR]

This paper proposes a new method to design a single-layer dual-band circularly polarized (CP) patch antenna with a small frequency ratio. The design consists of one or several pairs of rectangular patches proximity-fed by a 50- $\Omega $ microstrip line with an open-circuit termination. By exploiting both capacitive and inductive coupling mechanisms, and both orthogonal radiating modes of these patches, the antenna can be designed to operate at two close resonance frequencies. Due to its simple and single-layer structure, the antenna can be easily adapted with meshed configuration, which is suitable for transparent devices. For verification, a dual-band CP meshed patch antenna with a frequency ratio of 1.12 and two pairs of patch is designed, fabricated, and tested. The measurements show that the antenna prototype provides a $|S_{11}| < -10$ -dB bandwidth of 4.82–5.03 GHz (210 MHz) and 5.49–5.78 GHz (290 MHz), axial ratio < 3-dB bandwidth of 4.88–4.93 GHz (50 MHz) and 5.50–5.57 GHz (70 MHz), and broadside realized gains of 9.0 dBic and 8.6 dBic for the lower and upper bands, respectively.

The current research work, presents a compact dual-band and wideband slotted rectangular microstrip patch antenna. The system comprises three circular slots on the patch and a defected ground plane to achieve dual-band and wideband operation. The parametric variations applied to the proposed structure resulted in dual operating frequencies at 4.5 GHz and 8.0 GHz. The antenna prototype exhibits a good radiation pattern, directivity, and surface current over the bandwidth of 364 MHz (between 4.3 GHz and 4.7 GHz) and 2.5 GHz (between 6.5 GHz and 9.0 GHz). The proposed structure is fabricated with measured results of -21.87 dB at 4.5 GHz and -31.79 dB at 8.0 GHz for S11, respectively. The simulated and measured results are virtually identical. This indicates that the model is accurate, reliable, and best suited for 5G, satellites, and wireless applications. [ABSTRACT FROM AUTHOR]

This paper presents a discussion on a low-profile, frequency-reconfigurable penta-band antenna. This antenna consists of two asymmetric L-shaped rectangular patches electrically connected by a single PIN diode. The proposed antenna operates at five frequency bands depending upon the switching states of the PIN diode. It operates at 2.4 GHz (WLAN) and 5.3 GHz (5G) during forward bias of the diode, 3.3 GHz (5G) and 5.9 GHz (WLAN) during reverse bias of the diode and 4 GHz during zero bias condition providing a wide bandwidth (3.6–4.8 GHz) at this state. The antenna has voltage standing wave ratio (VSWR) ranges from 1 to 2, gain value ranges from 2.6 to 5.0 dBi, and a maximum radiation efficiency of 85%. This antenna can be integrated with modern devices such as smart phones, laptops, and other handheld devices due to its simplistic geometry. A prototype of the model is fabricated, and the results are validated.

Recent research has shown that choosing the right substrate for dielectric materials can enhance the antenna performance for the next generation of wireless communications. In this work, we present the results of the studies on the performance of the microstrip antennas for the new generation (5G) based on specific characteristics of the dielectric substrate. The simulation of the proposed patch antenna with the FR-4 Glass Epoxy substrate, in the frequency of 28 GHz, is provided significant values of gain, bandwidth, directivity, and radiation pattern compared to those given in the literature. [ABSTRACT FROM AUTHOR]

A dual-circularly polarized traveling wave antenna based on linear polarization array with wideband response is proposed. The circular polarization is realized by the sequential rotation arrangement of four linear polarization elements and series feeding with a phase difference 90°. Rotating four of such subarrays sequentially with a phase difference of 90° not only broadens the axial ratio (AR) bandwidth but also corrects the pattern beam deflection. Left-handed circular polarization (LHCP) and right-handed circular polarization (RHCP) are respectively achieved by exciting two different ports. The measured impedance bandwidth of the developed antenna array is 27.5 %. The 3-dB AR bandwidths of RHCP and LHCP are respectively 20.7 % and 22.4 % with the peak gains of about 8.7 and 8.3 dBic. [ABSTRACT FROM AUTHOR]

The rectangular Microstrip patch antenna is a popular choice for 5G applications due to its integrated design and wideband capabilities. Operating in the 1 GHz to 3 GHz range, this antenna boasts a gain of 4 dBi. In a recent study, researchers utilized the 5G mm-wave bands at a resonance frequency of 39 GHz to create a high-definition video antenna for various 5G applications. The proposed design incorporates a dielectric constant of 4.4 and was analyzed and simulated using HFSS software. Results from the simulation demonstrated a good bandwidth of 3.5 GHz, return loss of -31.87 dB, and a voltage standing wave ratio (VSWR) of 1.

This paper presents a discussion on a low-profile, frequency-reconfigurable penta-band antenna. This antenna consists of two asymmetric L-shaped rectangular patches electrically connected by a single PIN diode. The proposed antenna operates at five frequency bands depending upon the switching states of the PIN diode. It operates at 2.4 GHz (WLAN) and 5.3 GHz (5G) during forward bias of the diode, 3.3 GHz (5G) and 5.9 GHz (WLAN) during reverse bias of the diode and 4 GHz during zero bias condition providing a wide bandwidth (3.6-4.8 GHz) at this state. The antenna has voltage standing wave ratio (VSWR) ranges from 1 to 2, gain value ranges from 2.6 to 5.0 dBi, and a maximum radiation efficiency of 85%. This antenna can be integrated with modern devices such as smart phones, laptops, and other handheld devices due to its simplistic geometry. A prototype of the model is fabricated, and the results are validated. [ABSTRACT FROM AUTHOR]

A new design of a rectangular printed antenna for mobile communication is presented in this paper. The material substrate chosen is Rogers 3003c (∈r = 3) and DGS (Defected Ground Structure) is used for bandwidth enhancement. The proposed antenna resonates over 900, 1800 and 2600MHz frequencies for 2G/3G and 4G cellular phone. CST Microwave studio simulates the proposed rectangular printed antenna characteristics such as return loss S11, VSWR (voltage standing wave ratio), Gain and Radiation pattern. [ABSTRACT FROM AUTHOR]

This study discusses the design of a low-profile metamaterial-based antenna consisting of a 3 × 5 array of Hilbert shaped unit cells organised as a rectangular patch. The antenna is backed by with a partial ground plane loaded with square electromagnetic band gap defects for energy harvesting applications in the context of ultra-wideband self-powered wearable wireless devices. The antenna is mounted on a 28 × 32 mm FR4 substrate, with a thickness of 0.394 mm, a relative permittivity of 4.2 and a loss tangent of 0.02. The antenna is also printed on a flexible solar panel for self-powered devices through solant–rectenna output terminals. The proposed solant–rectenna is found to cover the frequency range from 0.8 up to 10 GHz. The I–V characteristics of the solar panel are measured with and without the antenna structure to realize low shadowing effects. After that, the solant radiofrequency (RF) port is connected to a rectifier circuit to create a rectenna port that collects the RF energy and converts it to an output DC voltage at 0.915 GHz. It is found that the proposed rectenna provides an output DC voltage of 1.42 V with a conversion efficiency of 90%.

In this work, design and analysis of microstrip patch antenna is carried out. A (2 X 1) antenna array is considered, with dimensions (W x L) as 35.11 mm x 27.13 mm. The dielectric substrate is taken to be FR4 epoxy with dielectric constant as 4.3 and loss tangent of 0.02. Dual trapezoidal slots are introduced to improve the gain considerations for the considered antenna array. The simulations are carried out and it is observed that the gain is improved. As a second stage in the work, to improve the bandwidth of operation for the dual trapezoidal antenna array, the concept of partial ground is taken into consideration. The simulations are carried in HFSS. It is found out that the introduction of partial ground improved the bandwidth of the antenna structure considered while preserving the gain to the maximum extent possible. The gain was found to be 7.0875 dB with centre frequency 2.4020 GHz. The frequency range below -10dB for the considered antenna array structure with partial ground was around 2.3 GHz to 2.6 GHz. This range is utilized in the WiMax application which covers the frequency ranges (2.3 GHz to 2.4 GHz) and (2.496 GHz to 2.690 GHz).

This work offers an optimized microstrip patch antenna for 5G and Wi-Max applications. The proposed design is based on rectangular patch antenna embedded with frequency selective surface consisting of an array of 4  4 patches to increase the gain of the antenna by more than 7dB. FSS layer is mounted under the microstrip patch of the antenna which provides a stop band response with more than -60 dB loss at the frequency range 3.5 GHz and more than 30 dB at 6 GHz. [ABSTRACT FROM AUTHOR]

This article presents the design and analysis of 4-hexyl-4′-biphenylcarbonitrile (6CB) nematic liquid crystal (NLC)–based rectangular patch antenna for S-band and C-band communication applications. Two glass substrates with permittivity of 6.4, loss tangent of 0.01 and thickness of 1 mm each with 21 × 25 mm2 and 19 × 19 mm2 dimension has been used, and 0.005 mm air gap has been placed to fill 6CB NLC. A rectangular patch of 10 × 11 mm2 size has been considered over the top substrate to achieve the application specific bands. The designed antenna model-1 with air gap is resonating at 5 GHz (4.01–7.85 GHz) with minimum S11 of −24.2 dB. The proposed antenna model-2 is filled with 6CB NLC in the air gap between glass substrates is resonating at 3.3 GHz (2.61–4.45 GHz) with minimum S11 of −29.75 dB. Antennas of both air gaps filled, and liquid crystal material filled models are fabricated and tested through combinational analyser for validation. The correlation between transmitted and received signals of the antenna models are analysed with time domain analysis by taking the identical antennas in face to face and side by side condition. The simulated results from HFSS electromagnetic tool and fabricated antennas results in chamber are exhibiting good agreement with each other. [ABSTRACT FROM AUTHOR]

In this paper, a monopole type antenna applicable to WLAN and WiMAX standard frequency bands is designed and fabricated. The proposed antenna is designed to have rectangular ring and rectangular patch based on microstrip feeding for triple band characteristics and inserted two stub in the top of the rectangular ring patch to enhance impedance bandwidth characteristics. The proposed antenna has 18.0mm (2W1+W2) × 33.0mm (L7+L8+L9) on a dielectric substrate of 27.0mm(W1) × 44mm(L1) × 1.0mm size. From the fabrication and measurement results, impedance bandwidths of 660MHz (2,08 to 2.74GHz) for 2.4/2.5MHz band, 488MHz (3.40 to 3.88GHz) for 3.5MHz band, and 2,180MHz (4.61 to 6.79GHz) for 5,000MHz band were obtained based on the impedance bandwidth. The proposed antenna also obtained the measured gain and radiation pattern in the anechoic chamber. [ABSTRACT FROM AUTHOR]

Significant improvements in terms of bandwidth of reflectarray antennas have been achieved by introduction of innovative paper substrate dielectric materials. Three differently custom composed organic dielectric substrates have been characterized for dielectric properties using a broadband technique based on open ended coax cable method. The substrates show low dielectric permittivities of 1.81, 1.63 and 1.84 along with a loss tangent of 0.053, 0.047 and 0.057. Validation of using the proposed substrates for reflectarray antenna was done by modelling and fabricating reflectarray unit elements on the three substrates. Scattering parameter analysis of unit reflectarray elements show encouraging results with a broadband frequency response of 340 MHz at a phase gradient of 0.14°/MHz. Thus the proposed substrate could serve exceptionally to address the narrow bandwidth problem in reflectarray antennas. [ABSTRACT FROM AUTHOR]

This study develops a differential‐fed filtering patch antenna, which features superior frequency selectivity, compact size, low cross‐polarisation, and symmetrical radiation patterns. The proposed antenna consists of a rectangular patch on the top layer, which is differentially fed by a balun bandpass filter on the bottom layer. A pair of rectangular coupling slots were etched on the middle layer for energy coupling. The patch antenna performs not only as the radiator but also as the last resonator of the whole filter circuit for compactness. A prototype of the proposed filtering antenna operating at 2.45 GHz was fabricated and tested. The measured in‐band peak gain is 5.9 dBi with steep roll‐off at band edges, and the out‐of‐band gain is less than − 25 dBi. Moreover, symmetrical radiation patterns and low cross‐polarisation levels of − 22 dB are also realised for the proposed filtering antenna. [ABSTRACT FROM AUTHOR]

A novel printed rectangular slotted patch antenna with defected Ground plane(DGS) for dual-band operations is presented. By embedding a T-shaped strips and defecting L-shaped slot in the ground plane, triple-mode resonances for achieving dual operations bands can be excited for achieving additional resonances. The designed antenna has very small size of 15 x 20 x 0.8mm3 printed on FR4 substrate and operate over the frequency ranges, (3.2-3.6) GHz and (5.02-6.64) GHz suitable for WiMAX (3.5/5.5GHz),WLAN (5.2/5.8GHz) and ISM medical band (5.725-5.82GHz). Simulation results show that the antenna gives an acceptable gain over the operating bands. In addition, effects dimensions of the T-shaped strips and the DGS for this design on the electromagnetic performance are examined and discussed in detail. The antenna was simulated using Computer Simulation Technology Microwave Studio (CST MWS) based on the finite difference time domain (FDTD). Finally, the proposed antenna was fabricated and reflection coefficient parameter was measured to validate against simulation results. [ABSTRACT FROM AUTHOR]

Novel designs of modified rectangular shape printed monopole antenna for Ultra wide band response are proposed, which gives bandwidth across 1GHz-10 GHz range. Further two variations of rectangular shape patches to realize tunable notch characteristics, are also presented. They yield tunable notch characteristics in two different frequency bands. Proposed antennas give broadside radiation pattern with peak gain of 2 dBi. [ABSTRACT FROM AUTHOR]

Artificial neural networks (ANNs) have acquired enormous importance in computing of the performance parameters of microstrip antennas due to their generalized and adaptive features. However, recently the concept of support vector machines (SVMs) has become very much popular in performance parameters computation due to several attractive features over ANNs. Specifically, SVMs outreach ANNs noticeably in terms of execution time. Likewise, ANNs are having multiple local minima problem, whereas a global and unique solution is provided by SVMs. In this paper, several performance parameters like: resonant frequency, gain, directivity, and radiation efficiency of slotted microstrip antennas with modified ground plane are computed with the help of SVM formulation. Comparisons of different parameters of simulated and computed values are illustrated. The achieved radiation patterns at particular resonant frequency in different planes are included as well. A prototype of the optimized antenna is also fabricated and characterized. A good agreement is attained among the computed, simulated, and measured results. [ABSTRACT FROM PUBLISHER]

This paper deals with the advantages of Minkowski fractal geometries and Defected Microstrip Structure (DMS) techniques in designing and testing of a low profile, cost effective multiband antenna for WLAN and WiMAX applications. The design of microstrip patch antenna, application of Minkowski fractal property and the use of defected microstrip structure in improving the performance of the proposed antenna design are discussed in detail. Flame Retardant (FR4) Substrate and microsrip inset feed is used for the fabrication of proposed antenna design. The proposed antenna design is simulated using High Frequency Structural Simulator (HFSS) and the design is fabricated and tested. The performance of the proposed antenna is analyzed based on the tested results. [ABSTRACT FROM AUTHOR]

This paper deals with the characterization of Rectangular Patch Antenna Arrays numerically and experimentally. This antenna is designed to work around frequency of 9.4GHz for radar applications. In the design process, the Computer Simulation Technology (CST®) simulator software is utilized to determine the value of the antenna parameters such as gain, radiation pattern, and voltage standing wave ratio (VSWR). The Rectangular Patch Antenna Arrays realized by using the 1x16 patch antenna array, while the patch antenna is implemented using microstrip lines. The Duroid/RT5880 substrate with a dielectric constant of 2.2 and a thickness of 1.57mm applied for implementation. The characterization results show that the VSWR of realized antenna is 1.052, and the gain is 15,26dB which is 1.4dB lower than the design result, while the radiation pattern is unidirectional and elliptical polarization. [ABSTRACT FROM AUTHOR]

This communication presents a single-layered broadband dual-band reflectarray with linear orthogonal polarizations in two adjacent bands. The reflectarray is designed to focus a broadside beam at 10.7–12.7 GHz band in vertical polarization and 12.7–14.7 GHz band in horizontal polarization, respectively. Different from the traditional square grids adopted in many reflectarray designs, this communication proposes subwavelength rectangular grids in a single-layered structure for achieving broad bandwidth in both the bands. Two pyramidal horn antennas with opposite positions are employed to feed the reflectarray for vertical and horizontal polarizations, respectively. The elements consist of single-layered patches arranged in subwavelength rectangular grids. To realize the dual-band operation, one dimension of the patches is adjusted to direct the beam at the lower band in vertical polarization, whereas the other orthogonal dimension is tuned to focus the beam at the upper band in horizontal polarization. The measured results show that the proposed dual-band reflectarray can realize a broad 1.5-dB gain bandwidth of 24% and 21% with aperture efficiency of 48% and 38% for the lower and upper band, respectively, which demonstrates better behavior than various existing dual-band designs adopting traditional square grids. [ABSTRACT FROM AUTHOR]

This paper presents a detailed explanation on the design of a novel triple frequency rectangular slot antenna for wireless local area network (WLAN) applications in IEEE 802.11b/g/a systems. This proposed antenna operates in ISM band at frequency of 2.4 Ghz and also in C band at 4.85 Ghz AND 6.1Ghz. The antenna has been designed and simulated on a foam substrate with dielectric constant of 1.06 and a thickness of 7 mm. The design is analysed by Finite Element Method based HFSS Simulator Software (version 13.0) by which return loss, 3D polar plot and Gain of the antenna are computed. In addition, the measured results show good radiation characteristics at the three operating frequencies, proving the dual-band operation of the proposed antenna. [ABSTRACT FROM AUTHOR]