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In this paper, a circular patch monopole antenna is proposed for super wideband (SWB) application. The SWB property is achieved by tapering the ground plane and feedline as well. In addition, a rec...

In this study, a rectenna (antenna + rectifier) performance is compared with two different types of antennas; planar and DRA. The CST Microwave Studio and Advance Design System (ADS) is used to perform co-simulation. In this, first a .S2P is generated using two similar antennas keeping at a far-field distance in CST, afterward it is imported in ADS and tested with a typical rectifier circuit. Further, two experimental methods are performed in indoor and outdoor environments to validate the simulation results. In the indoor environment, a horn antenna excited with a signal generator is used as an RF power transmitter. In contrast, in the outdoor environment, the horn antenna is replaced with an ambient power source like a mobile base station. In both methods, at receiving side rectenna (antenna + rectifier) is kept in the far-field region. Here, both planar metallic and dielectric resonator antennas are use done after another with the rectifier circuit to test the rectenna system. From the simulation and experiments performed in indoor and outdoor environment method, it is confirmed that the rectenna system tenders the best performance with dielectric resonator antenna.

A wideband differential Fabry–Perot cavity antenna (FPCA) is presented. Unlike the mostly used patch antennas, a rectangular dielectric resonator antenna (DRA) has been investigated as primary radiation source. A compact partially reflective surface (PRS) is proposed and used as superstrate layer over the DRA for wideband gain enhancement. Measurements show that the antenna exhibits a wide impedance bandwidth (for |S 11

In this paper, a wideband bandpass filter (BPF) is proposed with three transmission zeros (TZs) that are created using immittance inverters. Impedance- (K-) and admittance- (J-) inverters are integrated with the high-pass and low-pass sections, respectively, and both sections are integrated to obtain a bandpass response. Controllable TZs are created near the passband for improving the skirt factor (SF). For the theoretical investigation and validation, a lumped equivalent circuit model of the proposed BPF is extracted with the quasi-lumped element techniques. The simulation results of electromagnetic (EM)/distributed model, equivalent lumped circuit model, and measured results of fabricated prototype BPF are in good agreement. Fabricated EM/distributed BPF has a center frequency of 2.17 GHz, with a fractional bandwidth of 67.3% (1.4–2.9 GHz). The measured insertion loss and group delay at the center frequency are 0.57 dB and 5.91 ns, respectively. A high SF of 0.97 is achieved at both the cutoff frequencies with the compact physical circuit size 20.5 $\text {mm} \times 28$ mm and normalized circuit size $0.24\lambda _{g} \times 0.33\lambda _{g}$ .

An effective scheme is proposed and investigated to improve the performance of thin film solar cells using a two-dimensional (2-D) plasmonic grating structure at the rear electrode or back metal contact. The proposed light trapping scheme replaces the conventional flat rear electrode by a corrugated electrode with a square mesh of periodic grooves forming a 2-D plasmonic grating. The grating surface diffracts the light and increases the path for reflected light. Further, the energy of surface plasmons excited inside the grooves gets coupled to the absorber layer. An efficient light trapping scheme and surface plasmons resonance conjointly increase the absorption in the absorber layer of solar cell, which results as enhanced efficiency. Maximum contribution of light path enhancement and surface plasmons is achieved by optimizing the periodicity, width, and depth of the grooves. The proposed design is compared with the conventional simple solar cell as well as with the solar cell having the rear electrode with 1-D plasmonic grating structure to demonstrate the effectiveness of the scheme. Finally, the optimized design is proposed which exhibits 92% absorption, 43% enhanced light path and more than 200% increase in the short circuit current as well as conversion efficiency.

This paper presents a patch loaded slot antenna for super wideband (SWB) application. To obtain SWB characteristic, the proposed antenna geometry combined a rectangular slot and an overlying patch excited by a trident shaped microstrip feed. It is observed that the hybrid nature of the proposed antenna effectively enhances the impedance bandwidth up to 120%, by combining the resonance of both patch and slot. Besides, it is investigated that after converting the conventional tapered feed into the trident shape feed, the impedance bandwidth is increased further from 120% to 167% ranging between 1.25 to 15 GHz. Moreover, one U-shaped slot and two L-shaped stubs are inserted into the antenna design to introduce the dual-band rejection property from 1.8 to 2.4 GHz (GSM 1800, Wi-Fi 2.1 and 2.4) and 3.1 to 4.2 GHz (WiMAX and C-band). Further, to validate the simulation results a prototype is fabricated and tested. The measured result shows that the proposed antenna offered an impedance bandwidth of 170.3% from 1.2 GHz to 15 GHz.

A modification to the conventional anti-reflection coating (ARC) is proposed to improve the performance of the amorphous silicon solar cells. The performance is improved by replacing the conventional anti-reflection coating (ARC) by a modified ARC. The modified ARC has an embedded array of silver Yagi–Uda nanoantenna. Due to the highly directive and broadband characteristics of Yagi–Uda nanoantenna, the modified ARC minimizes the reflection over large range wavelengths and guides the incoming solar radiation towards absorber layer effectively which results in increased absorption and subsequent increase in the short-circuit current density. Solar cell with proposed ARC exhibits 1.66 times improved short-circuit current density and 1.43 times increased conversion efficiency. To the best of our knowledge, this is the first report on a Yagi–Uda nanoantenna incorporated in a solar cell to improve its performance.

A multiband C shape slot reconfigurable MIMO antenna integrated with wideband sensing antenna is proposed for cognitive radio (CR) application. The wideband sensing antenna designed for CR is offering an impedance bandwidth of 5.15 GHz (0.85–6 GHz). The frequency-reconfigurable C slot-based MIMO antenna referred as communicating antenna in CR is capable to switch between multiple frequency sub-bands, i.e., 1.8, 2.1, 2.5 and 3.6 GHz, assigned for various communication applications. A two-element reconfigurability MIMO antenna is acknowledged by utilizing the PIN diode. The proposed MIMO antenna for CR could improve data throughput and channel capacity of the system. Both antennas share the same substrate/platform could be used to sense electromagnetic spectrum in a wide range and to communicate using GSM, LTE, UMTS, 3G, Wi-Fi, Bluetooth, WiMAX and WLAN frequency bands, respectively.

A novel approach based on the extraordinary transmission is proposed to improve the photovoltaic properties of thin film solar cells. In this approach, a perforated gold film with a periodic array of square holes is embedded inside the absorber layer of the solar cell at an optimum depth. The gold film also serves the purpose of an electrode to take dc output. The transmission of light through the film takes place due to the extraordinary transmission which leads to significant absorption increase in the absorber layer. To achieve the optimal response the periodicity of holes is varied and the corresponding solar cell parameters including short-circuit current and efficiencies are calculated. Here, we report that the increased absorption of solar energy gives almost twofold enhancement in short-circuit current density and optical conversion efficiency of the solar cell. The investigation is performed using finite difference time domain (FDTD) computational method.

This study presents two compact high-efficiency active integrated antennas (AIAs) working at 2.15 GHz. Both AIAs are realised by integrating the planar inverted-F antenna (PIFA) at the back side of the class-E power amplifier. In the first design, the antenna input impedance is transformed into an optimum impedance of the power amplifier. It achieves the maximum power added efficiency (PAE) of 68.6% with a total dimension of 0.36 λ 0 × 0.32 λ 0 × 0.03 λ 0 ( λ 0 is calculated at 2.15 GHz). In the second design, the antenna directly connected to the drain terminal of the power amplifier and offers a maximum PAE of 74% with a compact size of 0.21 λ 0 × 0.17 λ 0 × 0.04 λ 0 , results in the size reduction of 59%. The novelty of the second design is it offers frequency reconfigurable nature by moving the shorting plate of PIFA without scaling the power amplifier and antenna, which can support Universal Mobile Telecommunications System (UMTS) (1920-2170 MHz), long term evolution (LTE)-40 (2300-2400), and Worldwide Interoperability for Microwave Access (WiMAX) (2500-2690 MHz) frequency bands. The measured results demonstrate that the proposed reconfigurable AIA yields the maximum PAE of 64% at both frequencies 2.3 and 2.6 GHz.

A compact monopole with multiple band notches filtering antenna is analyzed in this paper. The monopole antenna includes a rectangular patch which covers the ultra-wideband (UWB) frequency range from 3.1GHz to 10.6GHz. Further to reject the interfering licensed frequency bands like WiMAX, wireless local area network (WLAN) and X-Band, λg/2 resonators are used. The rectangular split ring resonator within monopole radiator is used to create band notch at 3.5GHz (WiMAX) and E shaped dual notch resonator for notch bands at 5.8GHz (WLAN) and 8.4GHz (X-Band). The proposed prototype is designed and simulated in commercially available software known as CST Microwave Studio. Simulated results are showing the performance of proposed filtering antenna as desired.

In this paper, a 4×4 inverted L-monopole antenna with semi elliptical radiating patch is proposed for 5G application in sub-6GHz (3.5GHz) band. All the antenna elements are placed orthogonally to attain pattern diversity. Moreover, a neutralization line associated with square ring at the middle of the ground plane is introduced which mitigate the near field coupling among antenna elements and in turns improves the isolation (>20dB). Moreover, it helps to realize a compact structure (0.64λx0.64λ mm2where λ is the free space wavelength). The proposed MIMO antenna is working in the frequency range 3.36-3.68 GHz (10 dB impedance bandwidth = 320MHz). The radiation patterns are in orthogonal directions, which provide the pattern diversity in the MIMO antenna. The simulated antenna peak gain is 2.8 dB at the desired frequency (3.5GHz) and the maximum efficiency is 52%. Moreover, overall low ECC (

This paper deals with the design of a $$2\times 2$$ Integrated Filter Antenna array working at 5.2 GHz for IEEE 802.11a WLAN application. The filtering action is incorporated into the conventional antenna array, rendering enhanced selectivity and sharper gain roll-off than the conventional approach. An equivalent circuit model is extracted to validate the working of the proposed design. Fractional band width of $$3.0\%$$ around 5.2 GHz (ranging between 5.15 and 5.31 GHz) and maximum gain of 11.11 dBi is obtained through this design.

A circularly polarised filtering dielectric resonator antenna is proposed. Left hand circularly polarised electromagnetic field is generated by virtue of a rectangular ring slot present on the ground plane of the dielectric laminate, beneath the dielectric resonator antenna, which is fed by a 50 Ω microstrip line. Additionally, a semi-elliptical shape bandpass filter is incorporated in the feed line to produce high selectivity, flat gain and wide stopband. A detailed analysis of the filter and the antenna has been carried out. The design offers fractional bandwidth of 6.13% ranging from 7.9 to 8.4 GHz, gain around 5.3 dBic and 3 dB axial ratio bandwidth of 3.68%. The simulated radiation efficiency is >80% in the pass band. The proposed structure has been fabricated and the results are compared with the simulated values.

In this paper, a compact planar CPW-fed antenna operating over the four frequency bands is proposed for RF energy harvesting applications. The proposed antenna includes five radiating elements and a stepped ground plane, occupies a total area of 48 × 42 mm2. By virtue of stepped ground plane, the antenna exhibits a better impedance match compared to the antenna with the full ground plane. The measured | S 11 | better than −10 dB is obtained at the frequency bands GSM-900, GSM-1800, Wi-Fi 2.1 GHz and Bluetooth (2.4 GHz), showing its suitability for RF energy harvesting application. For this to be feasible, the developed antenna is matched with the rectifier at four desired frequencies using a compact quad-band matching network. The merit of the proposed rectifier circuit is it can be extended for n number of frequency the band by using only 3n-1 number of lumped elements. To validate the design method experimentally, a prototype of a dual-band rectifier is also fabricated. The measured result demonstrates that the proposed dual-band rectifier circuit achieved the peak efficiency of 42 % and 38 % for 0.9 and 2.1 GHz, respectively at a load impedance of 4.7 k Ω .

In this paper, a low profile dielectric resonator antenna (DRA) is proposed and investigated. To achieve the broad impedance bandwidth the proposed antenna geometry combines the dielectric resonator antenna and an underlying microstrip-fed slot with a narrow rectangular notch, which effectively broadens the impedance bandwidth by merging the resonances of slot and DRA. The physical insight gained by the detailed parametric study has led to find out a set of guidelines for designing the antennas for any particular frequency band. The design guidelines have been verified by simulating a set of antennas designed for different frequency bands. For validation, a prototype antenna is fabricated and tested experimentally. The measured results show that the proposed DRA offers an impedance bandwidth of about $$125.34\%$$ from 1.17 to 5.1 GHz with reasonable gain between 3.5 and 5.7 dBi. The volume of the proposed DRA is $$0.16\lambda _{dr}^{3}$$ , where $$\lambda _{dr}$$ is the wavelength at center operating frequency of the DR. A comprehensive study on bandwidth shows that the proposed DRA provides maximum bandwidth in terms of the DR volume ( $$\hbox {BW}/V_{dr}$$ ) and the DR height ( $$\hbox {BW}/h_{dr}$$ ) than the other similar reported work on hybrid wideband DRA designs.

This paper presents a compact active integrated antenna (AIA) comprising of class-A power amplifier (PA) and stepped impedance planar inverted-F antenna (PIFA). In the proposed design, a common ground is used for both PA and PIFA, resulting a compact antenna of size 0.14λ 0 × 0.11λ 0 × 0.01λ 0 (λ 0 is free space wavelength at 0.85 GHz). Moreover, it is demonstrated that by using the stepped impedance radiator the operating frequency of the active PIFA is shifted down from its natural resonant frequency of 1.36 GHz to 0.85 GHz, offering an extensive size reduction of 80%. This active integration increases the passive antenna gain through the effective loading of the antenna to the power amplifier. The measured result indicates that the active and passive antennas achieved the gain of 15.7 dB and 3.81 dBi, respectively after the integration. In addition, the maximum SAR value of antenna is found to be 0.64 W/kg.

This paper presents a broadband hybrid slot-dielectric resonator antenna for radiofrequency (RF) energy-harvesting application. The antenna geometry consists of a simple pentagon-shaped dielectric resonator antenna (PDRA) excited by a microstrip feed underlying rectangular slot with narrow notch. It is investigated that the bandwidth of the proposed PDRA is improved significantly owing to electromagnetic coupling between feeding slot and the dielectric resonator. The measured results demonstrate that the proposed PDRA achieves an impedance bandwidth of 110.8%, covering the frequency range from 0.86 to 3 GHz in addition of stable radiation pattern with peak gain of 6.8 dBi and more than 90% radiation efficiency throughout the band, showing its suitability for RF energy harvesting application. For this to be feasible, the developed antenna is matched with the rectifier at two public telecommunication bands of GSM-900 and GSM-1800 using a compact dual-band hybrid matching network. The measured result demonstrates that the proposed dual-band rectenna system provides the peak efficiency of 63 and 59% for a load impedance of 4.7 kΩ at 0.9 and 1.8 GHz, respectively.

This paper focuses on various design constraints of radio frequency energy harvesting circuit (RFEHC). Matching networks such as L- and Π-type are used to investigate the RFEHC performance. The sim...

A novel high gain and broadband hybrid dielectric resonator antenna (DRA) is designed and experimentally validated. To obtain the wide impedance bandwidth, the proposed antenna geometry combines the dielectric resonator antenna and an underlying slot with a narrow rectangular notch, which effectively broadens the impedance bandwidth by merging the resonances of the slot and DRA. An inverted T-shaped feed line is used to excite both antennas, simultaneously. It supports amalgamation of different resonant modes of the both, DRA and slot antenna. The measured results show that the proposed antenna offers an impedance bandwidth of 120% from 1.67 to 6.7 GHz. The antenna gain is next enhanced by a reflector placed below the antenna at an optimum distance. On engineering the height and dimension of this reflector the antenna gain is improved from 2.2 dBi to 8.7 dBi at 1.7 GHz. Finally, antenna operation is attested experimentally with a rectifier circuit in the frequency range of 1.8–3.6 GHz, where various strong radio signals are freely available for RF energy harvesting. The measured maximum efficiency of the rectifier and rectenna circuit were found to be 74.4% and 61.4%, respectively.

In this letter, a new varactor-tuned low-pass filter (LPF) with sharp roll-off factor at different tunable frequencies and wide stopband is presented. By loading the low-impedance stubs of stepped-impedance resonators with the varactor diodes in shunt and a tunable coupling network in series, the cutoff frequency is tuned. To increase the stopband, two semicircular slots are etched in the ground plane, and the patches are connected to feed lines at both ends. A prototype of the proposed tunable LPF is designed, fabricated, and tested. Simulation and measured results demonstrate a good agreement. Measured results show the tuning range 75% (1–2.2 GHz), with a roll-off factor of 50 and 70.6 dB/GHz at lower and upper cutoff frequencies, respectively. The stopband is extended up to 20 GHz for lower cutoff, maintaining a rejection level >10 dB.

In this work, a frequency reconfigurable MIMO antenna for 4G and early 5G applications is presented. The MIMO antenna design consists an array of two radiating/receiving elements positioned diagonally opposite to each other for better isolation (>12 dB) and pattern diversity. Each antenna element in MIMO array has a single module consisting two meandered radiating arms which could be connected or disconnected to the 50 Ω feedline electronically using two PIN diodes to operate in two switchable frequency bands/modes, 2.4 GHz or 3.5 GHz assigned for 4G/LTE and early 5G/Sub-6 GHz wireless communication technologies, respectively. The length of each radiating arm is around half-wavelength at operating frequency of interest (2.4 GHz or 3.5 GHz). The overall size of the MIMO antenna system is 120 mm × 60 mm × 1.52 mm. The proposed MIMO antenna configuration provides a 28.81% FBW (2.0 GHz to 2.7 GHz) and 49.7% FBW (2.57 GHz to 4.27 GHz) in both the resonance modes, respectively. The measured antenna gain values in two switchable frequency modes are 3.7 dBi and 4.2 dBi, respectively with overall efficiency > 60%. A low envelope correlation coefficient (0.0056 at 2.4 GHz and 0.0009 at 3.5 GHz) is achieved. Furthermore, the SAR and hand mode analysis is carried out to verify the performance of the MIMO antenna for mobile handset. The measured ergodic channel capacity of the MIMO antenna has been achieved more than 10b/s/Hz for both the mode.

A novel low profile dielectric resonator antenna (DRA) is presented in this study for broadband applications. An asymmetric E-shaped dielectric resonator is analysed and optimised numerically as a wideband radiator. The fundamental mode is excited along with three nearest higher modes inside the DRA. A detailed impedance transformation is discussed to merge these modes collectively resulting in a single wideband operation. A microstrip fed conformal strip is used to stimulate the DRA. The proposed DRA is fabricated and tested. For |S 11| ≤ −10 dB, the DRA offers a frequency band of 6.0–10.2 GHz with an impedance bandwidth of 52%. The measured and calculated results are compared and found in good match. The DRA's radiation characteristics are measured at different frequencies. A stable radiation pattern is observed throughout the band of operation. The measured gain of the wideband antenna is ranging from 4.5 to 8.1 dBi.

In this work a new hexagonal shape compact elliptical low pass filter (LPF) is introduced. To improve and extend the stop band, two additional transmission zeros are created by introducing three semi-circular slots in the ground plane. Insertion loss is 18 dB in the entire pass band. Rejection band is extended up to >20 GHz with attenuation level better than −20dB. Obtained roll-off factor is 100 dB/GHz and group delay is 0.25 ns.

A theoretical study on nanoantenna and its application in enhancing the performance of the thin film solar cell (TFSC) is presented. In this work, a novel design of nanoantenna i.e. Euler spiral nanoantenna (ESNA) is introduced, which has evolved after bending the conventional dipole nanoantenna in the manner of Euler spiral. The bending is performed up to an optimum length so that the antenna can equally respond to the two orthogonally polarized waves. Then the proposed nanoantenna in turnstile manner is examined for the intended application of enhancing the absorption in TFSCs. The antenna is placed on the absorber layer (Si amorphous) of the TFSC with a coating of Zinc Oxide. The simulation results show that the proposed ESNA can significantly increase the absorption in the absorber layer of the TFSC. The performance in terms of absorption and quantum efficiency of the solar cell incorporated with ESNA has been studied. ESNA confines the electric field in a larger area which results in absorption increase. The simulation results show that proposed ESNA can enhance the absorption up to 97.6% in the absorber layer and the photocurrent is enhanced by a factor of 1.39. To the best of our knowledge, this is the first study on Euler spiral nanoantenna and so as in its application with solar cells.

A frequency reconfigurable mobile handset antenna for future sub-6GHz band wireless services is proposed in this paper. The antenna is very simple in design with two dipole radiators designed on one side of a 120mm × 60mm circuit board. Frequency reconfigurable performance at 3GPP LTE band 40/41 and sub-6GHz band at 3.5GHz for 5G services (3GPP LTE band 42/43) is achieved in its two resonance modes. Good 3:1 VSWR bandwidth is obtained with 25% FBW and 11.89% FBW in the two resonance modes respectively. The antenna provides gain over 4dB in both the resonance modes of the antenna with more than 70% efficiency in the entire operation bandwidth. This antenna offers a simple yet effective design for future mobile handset antennas for sub-6GHz band services.

Pattern reconfigurable antennas are extremely important in the present-day world of wireless communication systems as they steer their radiation beam in specific directions to overcome interferences & adjust to surroundings. One such microstrip antenna proposed in this research work consists of a hexagon shaped Alford type loop radiator with a tapered ground plane for proper matching, fed by a coaxial connector. It consists of three pin diodes switched by changing bias voltages to achieve beam reconfigurability. The antenna operates in the 2.4GHz band with a 10dB impedance bandwidth from 2.33GHz to 2.58GHz, with rotating beam at angles of 60° covering the entire azimuthal plane. The antenna provides a maximum gain of 3dB with significant beamforming capability. Simulated results are presented in this paper.

A novel printed monopole antenna with filtering characteristics for ultra-wideband application is presented. The antenna consists of an elliptical radiating patch and a defected ground structure. An LPF is integrated on the feed line to get a sharp cut off at 10.6 GHz which also results in the improvement of out-of-band performance. The filter-antenna configuration is simple, compact and there is considerable improvement from basic antenna configuration. The fractional bandwidth is 115.7% and the impedance bandwidth is 7.7 GHz.

A dual band Circularly Polarized Dielectric Resonator Antenna (CPDRA) is presented in this paper. A single feed, aperture coupling technique is being used to obtain the CPDRA. A cross shaped DRA is placed above a rectangular ring-shaped slot which is truncated at the four corners. The slot is fed by a 50Ω microstrip line present on the opposite side. The proposed design gives a Fractional Bandwidth of 15% and 4.4% and 3-dB Axial Ratio Bandwidth 0.2 & 0.17 GHz around 8.0 and 11.2 GHz, respectively. The maximum gains at both the bands are 6.1 and 4.4 dBic, respectively. A detailed analysis of the operating principle and the results of the prototype are being carried out in this paper.

A class-E power amplifier integrated with a rectangular ring planar inverted-F antenna (PIFA) is presented in this paper. The proposed PIFA is very compact and occupying less volume 16 × 10 × 5.5 mm3. The measured result shows that the proposed PIFA offers an impedance bandwidth of 250 MHz from 2.3–2.55 GHz, which is useful for LTE band 40 and WLAN (2.4–2.48 GHz). The maximum power-added efficiency (PAE) of class-E power amplifier is found to be 70% at 2.3 GHz. Further, the proposed PIFA is integrated with the class-E power amplifier to design an active-integrated antenna. The simulated results of the active-integrated antenna are presented. It is found that the gain of the active-integrated antenna system is increased from 2.4 dBi (passive) to 17.2 dBi (active).

In this letter, a highly selective ultra wide band (UWB) band pass filter (BPF) with triple notch bands is proposed using C-Shaped and E-Shaped resonators along with a triangular ring loaded stub resonator (TRLSR) resting on a multi-mode resonator (MMR). The MMR is constructed using a uniform transmission line and parallel coupled lines connected to 50 $\Omega$ feed lines at both ends. Five even and odd modes are created to achieve an UWB passband response. Additionally, two transmission zeros at lower and upper cutoff frequencies of the passband are formed by TRLSR which helps to get a high skirt factor (SF) of 0.975. In addition, multiple notch bands are created using $\lambda_\mathrm{g}/2$ resonators to reject three interfering frequency bands named as WiMAX, WLAN, and X-Band. The center frequency of each notch can be controlled by tuning the length of the resonator. The proposed filter is simulated, fabricated, and tested experimentally. Both the predicted and the measured results are in good agreement and replicating the behavior of the proposed filter.

In this paper a multifunctional antenna is presented which offers an ultra-wideband (UWB) operation, an UWB operation with two switchable notches and reconfigurable dual-band operation for WiMAX and WLAN applications, respectively. Total seven functions/states could be achieved from a single antenna using an electronic switching. The antenna uses dual slots on the ground plane to provide a wide bandwidth, ranging from 3.1 GHz to 10.6 GHz. U-Shaped slot and C-Shaped printed strip in the ground are used to generate two notches at 3.6 GHz(WiMAX) and 5.2 GHz (WLAN/ WiFi) bands, respectively. Moreover, four parasitic strips are added in the feed side to make antenna functional at either3.6 GHz or 5.2 GHz or both. Total Five PIN diodes are required to obtain seven operations from the proposed antenna. Seven structures are fabricated and measured to verify the seven states and results are found in good agreement with estimated results obtained from the simulation.

This paper deals with a 2×2 Integrated Filter Antenna (IFA) array designed at 5.2 GHz. By incorporating the filtering action in the conventional antenna array, the need for an additional filter for suppressing the out-of-band signals has been avoided. In order to achieve this the last resonator of the filter has been replaced by a slot antenna, operating at the same band as that of the filter, in each arm of the array. The overall dimension of the subsystem has been optimized to 1.56λ 0 × 1.56λ 0 . It has got a fractional bandwidth of 3.0% at 5.2 GHz. The sub-system provides a maximum gain of 12.43 dBi and HPBW of 33° in broadside direction. The proposed structure was designed, simulated and fabricated. The measured reflection co-efficient plot shows a shift of 0.09 GHz of the overall band which may be due to the fabrication tolerances.

In this paper, impact of diode's nonlinearity on the harvesting circuit performance is studied using LSSP simulation. Based on this study, two reactance compensation techniques are developed for a single band harvesting circuit. These techniques compensate the capacitive reactance of the circuit and thus sustain its resonance for a specific power range (−20dBm to 10dBm). Both circuits have been fabricated and tested. The measured results are compared with simulated results to validate our proposed techniques. A good agreement is obtained. The measured output voltage of the proposed harvesting circuit is found to be 1.5V for an input of −5dBm.

In this paper, LTE band 40 (2300–2400MHz) Multiple input Multiple output (MIMO) Antenna array is proposed. MIMO antenna array consist of two diagonally placed angular ring slot antenna cut from two edges of ground plane. MIMO antenna array has a volume 60 × 60 × 1.5 mm3. Two antenna elements are placed orthogonal to each other and stubs are arranged to improve isolation between two antenna and envelope correlation coefficient characteristics. Channel capacity of proposed MIMO antenna is calculated based only on S-parameters. Performance of MIMO antenna in terms of S-parameter, envelope correlation coefficient (ECC), radiation pattern, capacity loss, channel capacity, TARC is simulated. The results shown that MIMO antenna array is good candidate for 100MHz bandwidth LTE band.

A differentially excited rectangular dielectric resonator antenna (RDRA) is proposed. The RDRA is excited with two equal magnitude signals with 18° out of phase. A well accepted hybrid coupler is designed on the same substrate and integrated with the RDRA. The RDRA able to achieve an optimum impedance bandwidth of 33.6% at center frequency of 2.76 GHz with this proposed feeding arrangement. The proposed feeding arrangement also provides a control over the impedance bandwidth. A detailed parametric variation is presented. The RDRA shows a stable radiation pattern with a steady gain of 6∼7.2dBi in the broadside direction over the frequency band of interest.