Showing papers on "Patch antenna published in 2015"
TL;DR: In this article, a novel kind of patch antenna with high-selectivity filtering responses and high-gain radiation performance is presented, which is mainly composed of a driven patch and a stacked patch, with its entire height being ${0.09\lambda }$.
Abstract: This paper presents a novel kind of patch antenna with high-selectivity filtering responses and high-gain radiation performance. The proposed antenna is mainly composed of a driven patch and a stacked patch, with its entire height being ${0.09\lambda }$ . Three shorting pins and a U-slot are embedded in the driven patch to enhance out-of-band suppression levels and skirt selectivity near the lower band-edge, whereas the stacked patch provides a sharp roll-off rate at the upper band-edge and also an enhanced gain. Without using extra filtering circuits, the proposed antenna exhibits a quasi-elliptic boresight gain response with three radiation nulls. For demonstration, an antenna is implemented covering the LTE band (2.3–2.7 GHz). The antenna achieves an average gain of 9.7 dBi within passband, and out-of-band suppression levels of more than 21 dB.
330 citations
TL;DR: In this paper, a metamaterial-based broadband low-profile grid-slotted patch antenna is presented, where a periodic array of series capacitor-loaded patch cells is formed, and excited through the coupling aperture in a ground plane right underneath and parallel to the slot at the center of the patch.
Abstract: A metamaterial-based broadband low-profile grid-slotted patch antenna is presented. By slotting the radiating patch, a periodic array of series capacitor loaded metamaterial patch cells is formed, and excited through the coupling aperture in a ground plane right underneath and parallel to the slot at the center of the patch. By exciting two adjacent resonant modes simultaneously, broadband impedance matching and consistent radiation are achieved. The dispersion relation of the capacitor-loaded patch cell is applied in the mode analysis. The proposed grid-slotted patch antenna with a low profile of $0.06 \lambda_{0}$ ( $\lambda_{0}$ is the center operating wavelength in free space) achieves a measured bandwidth of 28% for the $\vert{\text{S}_{{11}}}\vert$ less than $-{10}\;\text{dB}$ and maximum gain of 9.8 dBi.
239 citations
TL;DR: In this paper, a low-profile single-feed circularly polarized (CP) patch antenna using metasurface is proposed for broadband operation, which is comprised of a truncated corner square patch sandwiched between a lattice of $4 \times 4$ periodic metal plates and the ground plane.
Abstract: A low-profile single-feed circularly polarized (CP) patch antenna using metasurface is proposed for broadband operation. The antenna is comprised of a truncated corner square patch sandwiched between a lattice of $4 \times 4$ periodic metal plates and the ground plane. Surface waves propagating on the metasurface are excited in the proposed structure. This phenomenon generates additional resonances and minimum axial ratio (AR) points for the radiating structure, consequently broadening the impedance-matching and AR bandwidths of the antenna. The final prototype, with an overall size of $32\;{\text{mm}} \times 32\;{\text{mm}} \times 3\;{\text{mm}}$ ( $0.58{\uplambda}_{\text o} \times 0.58{\uplambda}_{\text o} \times 0.056{\uplambda}_{\text o}$ at 5.5 GHz), was fabricated and tested. The measurements resulted in a $\vert{S}_11 \vert bandwidth of 4.70–7.48 GHz (45.6%) and a 3-dB AR bandwidth of 4.9–6.2 GHz (23.4%). In addition, the antenna yielded a good broadside left-hand CP radiation with a small gain variation (7.0–7.6 dBic) and a high radiation efficiency ( ${>} 90$ %) within the operational bandwidth.
215 citations
TL;DR: In this paper, a very compact ultrawideband (UWB) multiple-input multiple-output (MIMO) antenna with high isolation is presented, consisting of two UWB slot antennas.
Abstract: A very compact ultrawideband (UWB) multiple-input multiple-output (MIMO) antenna with high isolation is presented in this letter. The proposed antenna, consisting of two UWB slot antennas, has a very compact size of $22 \times 26~\hbox{mm}^{2}$ , which is smaller than most of UWB antennas only with single antenna element. A T-shaped slot is etched on the ground to improve the impedance matching characteristic in the low-frequency and reduce the mutual coupling for the frequencies $ \geq 4~\hbox{GHz}$ . By etching a line slot to cancel out original coupling, isolation enhancement at the 3–4 GHz band is achieved. The antenna possesses a low mutual coupling of less than $ - 18~\hbox{dB}$ over the operating band from 3.1–10.6 GHz. The performance of this antenna both by simulation and by experiment indicates that the proposed antenna is a good candidate for UWB applications.
214 citations
TL;DR: In this article, a high-gain transmitting lens antenna by employing layered phase-gradient metasurface (MS) was proposed to focus the propagating plane wave to a point with high efficiency.
Abstract: We propose a high-gain transmitting lens antenna by employing layered phase-gradient metasurface (MS). The MS is engineered to focus the propagating plane wave to a point with high efficiency. An X-band patch antenna is placed at the focal point of the MS as a feed source, and then the quasi-spherical wave emitted by the source is transformed to plane wave. Due to the successful conversion of quasi-spherical wave to plane wave, the beam width of the patch antenna has been decreased 66° and the gain has been enhanced 11.6 dB. The proposed lens antenna not only opens up a new route for the applications of phase-gradient MS in microwave band, but also affords an alternative for high-gain antenna.
189 citations
TL;DR: In this article, a compact circularly polarized (CP) co-designed filtering antenna is reported, which is based on a patch radiator seamlessly integrated with a bandpass filter composed of coupled stripline open-loop resonators, which are designed together as a system.
Abstract: A compact circularly polarized (CP) co-designed filtering antenna is reported. The device is based on a patch radiator seamlessly integrated with a bandpass filter composed of coupled stripline open-loop resonators, which are designed together as a system. In the proposed design, the patch functions simultaneously as the radiator and the last stage resonator of the filter, resulting in a low-profile integrated radiating and filtering module with a small overall form factor of $\mathbf{0.53{\lambda _0} \times 0.53{\lambda _0} \times 0.07{\lambda _0}}$ . It is shown that the filtering circuit not only ensures frequency selectivity but also provides impedance matching functionality, which serves to broaden both the impedance and axial ratio bandwidths. The designed filtering antenna was fabricated and measured, experimentally achieving an $\mathbf{{S_{11}} , an axial ratio of less than 3 dB and a gain higher than 5.2 dBi over a bandwidth from 3.77 to 4.26 GHz, i.e., around 12.2%, which makes it an excellent candidate for integration into a variety of wireless systems. A linearly polarized version of the integrated filtering antenna was also demonstrated. In addition, further full-wave simulations and experiments were carried out to verify that the designed CP filtering antenna maintains its properties even when mounted on different positions of the human body with various body gestures. The stable impedance and radiation properties also make it a suitable candidate as a wearable antenna for off-body wireless communications.
188 citations
TL;DR: In this article, a compact multiple-input-multiple-output (MIMO) antenna with band-notched function is presented for ultrawideband (UWB) applications.
Abstract: A compact multiple-input–multiple-output (MIMO) antenna is presented for ultrawideband (UWB) applications with band-notched function. The proposed antenna is composed of two offset microstrip-fed antenna elements with UWB performance. To achieve high isolation and polarization diversity, the antenna elements are placed perpendicular to each other. A parasitic T-shaped strip between the radiating elements is employed as a decoupling structure to further suppress the mutual coupling. In addition, the notched band at 5.5 GHz is realized by etching a pair of L-shaped slits on the ground. The antenna prototype with a compact size of $38.5 \times38.5~\hbox{mm}^{2}$ has been fabricated and measured. Experimental results show that the antenna has an impedance bandwidth of 3.08-11.8 GHz with reflection coefficient less than $-10~\hbox{dB}$ , except the rejection band of 5.03-5.97 GHz. Besides, port isolation, envelope correlation coefficient and radiation characteristics are also investigated. The results indicate that the MIMO antenna is suitable for band-notched UWB applications.
174 citations
TL;DR: Cavity-backed patch antenna arrays with full corporate substrate integrated waveguide (SIW) feed networks are demonstrated at V-band for applications with the needs of high-gain antennas.
Abstract: Cavity-backed patch antenna arrays with full corporate substrate integrated waveguide (SIW) feed networks are demonstrated at V-band for applications with the needs of high-gain antennas. A prototype of $16 \times 16$ radiating elements with a waveguide transition is fabricated by applying standard printed circuit board (PCB) facilities. A gain up to 30.1 dBi with a 3-dB gain bandwidth of 16.1%, an impedance bandwidth of 15.3% for $\mathrm{SWR} \,{ , and symmetrically broadside radiation patterns with $-40\,\mathrm{dB}$ cross-polarizations are achieved. The performance of the proposed antenna array is also systematically evaluated. The result serves as a reference for designing large antenna arrays operating at millimeter-wave frequencies.
174 citations
TL;DR: In this article, a multimode filtering antenna, which is realized by integrating a multi-modal resonator and an antenna, has been applied to the design of dual-polarized antenna arrays for achieving a compact size and high performance in terms of broad bandwidth, high-frequency selectivity and out-of-band rejection.
Abstract: A novel design concept of multimode filtering antenna, which is realized by integrating a multimode resonator and an antenna, has been applied to the design of dual-polarized antenna arrays for achieving a compact size and high performance in terms of broad bandwidth, high-frequency selectivity and out-of-band rejection. To verify the concept, a $2 \times 2$ array at C-band is designed and fabricated. The stub-loaded resonator (SLR) is employed as the feed of the antenna. The resonant characteristics of SLR and patch as well as the coupling between them are presented. The method of designing the integrated resonator-patch module is explained. This integrated design not only removes the need for separated filters and traditional ${50}{\text - }{\Omega }$ interfaces but also improves the frequency response of the module. A comparison with the traditional patch array has been made, showing that the proposed design has a more compact size, wider bandwidth, better frequency selectivity, and out-of-band rejection. Such low-profile light weight broadband dual-polarized arrays are useful for space-borne synthetic aperture radar (SAR) and wireless communication applications. The simulated and measured results agree well, demonstrating a good performance in terms of impedance bandwidth, frequency selectivity, isolation, radiation pattern, and antenna gain.
166 citations
TL;DR: In this article, a dual-band wearable fractal-based monopole patch antenna integrated with an electromagnetic band-gap (EBG) structure is presented for the GSM-1800 MHz and ISM-2.45 GHz bands.
Abstract: This letter presents the design of a dual-band wearable fractal-based monopole patch antenna integrated with an electromagnetic band-gap (EBG) structure. The prototype covers the GSM-1800 MHz and ISM-2.45 GHz bands. The EBG structure reduces the radiation into the human body over 15 dB. It also reduces the effect of frequency detuning due to the human body. The performance of the antenna under bending, crumpling, and on-body conditions has been studied and presented. Specific absorption rate (SAR) assessment has also been performed to validate the antenna for its usefulness in wearable applications.
160 citations
TL;DR: In this article, two different artificial magnetic conductor (AMC) unit cells are designed to obtain 180 $^\circ $ ( $ \pm 30^ √circ $ ) reflection phase difference over broadband frequency range.
Abstract: A design approach aimed at reducing the radar cross section (RCS) of microstrip antenna in wide frequency band is proposed. First, two different artificial magnetic conductor (AMC) unit cells are designed to obtain 180 $^\circ $ ( $ \pm 30^\circ $ ) reflection phase difference over broadband frequency range. Then, chessboard configuration is structured with the two AMC unit cells and is applied to a microstrip antenna for RCS reduction. The simulated results indicate that the proposed antenna possesses remarkable RCS reduction from 8.0 GHz to 20.0 GHz for both polarizations, covering the working band of the original antenna. The maximum reduction is 31.9 dB. Moreover, the radiation performance of the antenna has been well kept. Measured results of the fabricated prototype are in good agreement with the simulations.
TL;DR: A wideband high-gain high-efficiency hybrid integrated plate array antenna for inter-satellite links is presented in this paper, which consists of microstrip patches, substrate integrated waveguide (SIW) and waveguide power dividers.
Abstract: A wideband high-gain high-efficiency hybrid integrated plate array antenna for inter-satellite links is presented in this paper This antenna consists of microstrip patches, substrate integrated waveguide (SIW) and waveguide power dividers A novel feeding structure is proposed to excite the microstrip sub-array with a wideband characteristic The radiation efficiency of SIW arrays with different sizes is compared by experiment The hybrid SIW-waveguide feeding topology is optimized to realize high efficiency, low cost and compact configuration at the same time The array antenna is fabricated through standard multi-layer PCB process and milling technology Measured results demonstrate about 146% of reflection coefficient bandwidth ( $\vert {\rm S}_{11}\vert dB) in the frequency band of 57–66 GHz The gain fluctuates less than 3 dB within the same band The 1 dB gain bandwidth is 81% within the frequency band of 59–64 GHz The maximum gain is 392 dBi at 59 GHz with the efficiency of 41%
TL;DR: A frequency-reconfigurable bow-tie antenna for Bluetooth, WiMAX, and WLAN applications is proposed, which shows that the proposed antenna can be tuned to operate in either 2.2-2.53, 2.97-3.71, or 4.51-6 GHz band with similar radiation patterns.
Abstract: A frequency-reconfigurable bow-tie antenna for Bluetooth, WiMAX, and WLAN applications is proposed. The bow-tie radiator is printed on two sides of the substrate and is fed by a microstripline continued by a pair of parallel strips. By embedding p-i-n diodes over the bow-tie arms, the effective electrical length of the antenna can be changed, leading to an electrically tunable operating band. The simple biasing circuit used in this design eliminates the need for extra bias lines, and thus avoids distortion of the radiation patterns. Measured results are in good agreement with simulations, which shows that the proposed antenna can be tuned to operate in either 2.2–2.53, 2.97–3.71, or 4.51–6 GHz band with similar radiation patterns.
Patent•
12 Mar 2015TL;DR: In this paper, a rectenna according to the present invention includes a circularpolarized patch antenna having dual slots fed by a microstrip and configured to receive and output a radio frequency (RF) signal, and a rectifying circuit configured to convert for output the RF signal, received by the circular-polarised patch antenna, into a direct current (DC) signal and transfer the DC signal from the antenna to a load, wherein the rectification circuit comprises at least one radial stub.
Abstract: A rectenna according to the present invention includes a circular-polarized patch antenna having dual slots fed by a microstrip and configured to receive and output a radio frequency (RF) signal, and a rectifying circuit configured to convert for output the RF signal, received by the circular-polarized patch antenna, into a direct current (DC) signal and transfer the DC signal from the antenna to a load, wherein the rectifying circuit comprises at least one radial stub.
TL;DR: In this paper, a dual-band three-pole Chebyshev filtering patch antenna with orthogonal polarizations in the two bands is developed for 2.4/5.8 GHz ISM-band applications.
Abstract: A compact dual-band three-pole Chebyshev filtering patch antenna with orthogonal polarizations in the two bands is developed for 2.4/5.8-GHz ISM-band applications. Step impedance resonators and aperture coupled feed techniques are integrated together to fulfill the goal. The synthesis procedure is discussed using formulation and design curves. The advantages of the proposed design, including harmonic suppression and controllable bandwidth, are verified by experiments. According to the summary table, this dual-band filtering antenna, realized in planar form, shows either a more compact size or improved radiation characteristics when compared with those reported in the open literature.
TL;DR: In this article, a stub-loaded microstrip patch antenna with reconfigurable operation in both frequency and polarization is presented, using 12 varactors with two independent voltages, achieving a fractional bandwidth of around 40% while allowing selection between circular polarization with both rotating senses and linear polarization (LP).
Abstract: A stub-loaded microstrip patch antenna with reconfigurability in both frequency and polarization is presented. Using 12 varactors with two independent voltages, reconfigurability is achieved in a fractional bandwidth of around 40% while allowing selection between circular polarization (CP) with both rotating senses and linear polarization (LP). The design is optimized based on an analytical model, which significantly speeds up the process while yielding reasonably accurate predictions. For illustration of the concept, an antenna is designed, optimized, and manufactured for reconfigurable operation in the 2.4–3.6 GHz frequency range. A good agreement between simulations and measurements is obtained which validates the proposed method. A full reconfigurability is demonstrated in the operation band with the ability to both tune the antenna to a given frequency and select a polarization state among left-hand or right-hand CP or various states of LP.
TL;DR: In this paper, a dual-band, wearable metamaterial-loaded antenna is proposed for 2.4/5.2 GHz WLAN applications, which features a low backward radiation in both bands.
Abstract: A dual-band, wearable metamaterial-loaded antenna is proposed for 2.4/5.2-GHz WLAN applications. The loading is with a composite right/left-handed transmission line (CRLH-TL) metamaterial, resulting in a significant miniaturization down to ${\lambda _0}/6 \times {\lambda _0}/6 \times {\lambda _0}/20$ . Similar radiation patterns are obtained by simultaneously exciting the first-order positive ( ${ n}=+1$ ) and negative ( ${ n}=-1$ ) modes. The antenna features a low backward radiation in both bands, which is highly desirable in minimizing electromagnetic coupling to the body. The antenna is fabricated fully using textiles except for the connector and is evaluated in free space and on body, under both planar and bent conditions. Besides a good agreement between simulations and measurements, results indicate that the proposed topology is reasonably immune to body coupling and robust with respect to mechanical changes. The specific absorption rate (SAR) level is numerically investigated to determine the on-body safety level.
TL;DR: In this paper, a differential microstrip antenna with improved gain for RF energy harvesting is presented, which can be used in either center grounded or differential configuration for GSM900 band (890-960 MHz).
Abstract: A differential microstrip antenna with improved gain for RF energy harvesting is presented in this paper. The developed antenna can be used in either center grounded or differential configuration. The antenna is designed and fabricated for GSM900 band (890–960 MHz). The antenna has a gain of 8.5 dBi at the center frequency and exhibits VSWR $\boldsymbol{\leq} 2$ for frequencies between 870 MHz to 1.05 GHz. The efficiency of the antenna is 80%. The developed antenna finds its application in energy harvesting, RFID tags and in wireless communication circuits, where differential inputs/outputs are needed. A complete differential RF energy harvesting system with a peak efficiency of 65.3% for a load of $3 {\mathbf{k}}\boldsymbol{\Omega}$ is also developed.
TL;DR: A study on the bandwidth performance of the proposed design reveals that wide bandwidth can be achieved for the antenna by choosing a thick supporting substrate between the water patch and the ground plane, and can be conveniently integrated with the solar cells to realize a dual-function design.
Abstract: A novel water dense dielectric patch antenna (DDPA) fed by an L-shaped probe is proposed and investigated. In contrast to the water antennas in the literature, including the water monopole and the water dielectric resonator antenna, the operation mechanism of the proposed water DDPA is similar to the conventional metallic patch antenna. The antenna is excited in a mode like the TM $_{{\textrm {10}}}$ mode of the rectangular patch antenna. An L-shaped probe, which is widely used for the conventional patch antenna, is used to excite the water DDPA. A study on the bandwidth performance of the proposed design reveals that wide bandwidth can be achieved for the antenna by choosing a thick supporting substrate between the water patch and the ground plane. A prototype is fabricated to confirm the correctness of the design. An impedance bandwidth of 8%, maximum gain of 7.3 dBi, radiation efficiency up to 70%, and symmetrically unidirectional patterns with low backlobe and low cross polarization levels are obtained. Furthermore, owing to the transparency of the water patch, the proposed water DDPA can be conveniently integrated with the solar cells to realize a dual-function design. Measurements on the prototype demonstrate that the existence of the solar cells does not significantly affect the performance of the antenna and vice versa.
TL;DR: In this article, an energy harvesting at 35 GHz has been developed, which known as a rectenna, an array of a rectangular microstrip patch antenna with 16 elements was used to efficiently convert RF to dc signal, and a step-impedance low-pass filter was used between the antenna and rectifier circuit to suppress second-order harmonic generated by the diode.
Abstract: In this letter, an energy harvester at 35 GHz has been developed, which known as a rectenna. An array of a rectangular microstrip patch antenna with 16 elements was used to efficiently convert RF to dc signal. A step-impedance low-pass filter is used between the antenna and rectifier circuit to suppress second-order harmonic generated by the diode. A GaAs Schottky diode MA4E1317 was used in parallel with load as a half-wave rectifier circuit. The fabrication process is based on conventional optical photolithography to obtain an integrated circuit. The maximum RF-to-dc conversion efficiency of 67% was successfully achieved with input RF power of 7 mW at 35.7 GHz.
TL;DR: In this paper, a multifunctional reconfigurable antenna (MRA) capable of operating in nine modes corresponding to nine steerable beam directions in the semisphere space is presented.
Abstract: A multifunctional reconfigurable antenna (MRA) capable of operating in nine modes corresponding to nine steerable beam directions in the semisphere space $\{-30^{\circ},0^{\circ}, 30^{\circ}\}; \phi\ \in \{0^{\circ}, 45^{\circ}, 90^{\circ}, 135^{\circ}\})$ is presented. The MRA consists of an aperture-coupled driven patch antenna with a parasitic layer placed above it. The surface of the parasitic layer has a grid of 3 $\,\times\,$ 3 electrically-small square-shaped metallic pixels. The adjacent pixels are connected by PIN diode switches with ON/OFF status to change the geometry of the parasitic surface, which in turn changes the current distribution on the antenna, thus provides reconfigurability in beam steering direction. The MRA operates in the IEEE 802.11 frequency band (2.4—2.5 GHz) in each mode of operation. The antenna has been fabricated and measured. The measured and simulated impedance and radiation pattern results agree well indicating an average of ${\sim} 6.5$ dB realized gain in all modes of operation. System level experimental performance evaluations have also been performed, where an MRA equipped WLAN platform was tested and characterized in typical indoor environments. The results confirm that the MRA equipped WLAN systems could achieve an average of 6 dB Signal to Noise Ratio (SNR) gain compared to legacy omni-directional antenna equipped systems with minimal training overhead.
TL;DR: In this paper, a patch antenna with parasitic strips is presented for wideband circular polarization, in which four parasitic strips are sequentially rotated and gap-coupled around the patch.
Abstract: A patch antenna with parasitic strips is presented for wideband circular polarization. In order to broaden the axial-ratio (AR) bandwidth of the original corner-truncated patch, four parasitic strips are sequentially rotated and gap-coupled around the patch. A capacitive-coupled feed with a small disc on the top of the feeding probe is utilized to obtain a wide impedance-matching bandwidth. Moreover, another disc-loaded shorting pin is placed at the center of the antenna to adjust the squint beams and improve the gains along $ + z$ -axis. Measured results show that the proposed antenna with a low profile of $0.13{\lambda _0}$ obtains a global bandwidth of 24% (2.32–2.95 GHz) for $\vert{S_{11}}\vert , ${\rm AR} , and average gain of 8 dBic.
TL;DR: In this article, a three-dimensional (3-D) filtering antenna with features of high selectivity and low cross-polarization is proposed and experimentally verified in this communication.
Abstract: A three-dimensional (3-D) filtering antenna with features of high selectivity and low cross-polarization is proposed and experimentally verified in this communication. Thanks to the vertically 3-D integration, the high selectivity at either frequency sides of the filtering antenna is achieved by a novel cross-coupling scheme between in-band and out-of-band modes in a single cavity located in the lower substrate, while the low cross-polarization in the far-field is realized due to the symmetric feed and radiators on a cavity-backed dual-slot antenna at the upper substrate. In our design, the cavity-backed dual-slot antenna performs not only a radiator but also the last resonator of the bandpass filter (BPF). A prototype is demonstrated at Ka -band with a center frequency of 31.495 GHz and fractional bandwidth of 1.56%. Two radiation nulls [transmission zeros (TZs)] at either frequency band edges can be observed and a cross-polarization level lower than $- 30\,\mathrm{dB}$ is obtained.
TL;DR: In this article, the authors describe the design of a novel planar multiple-input-multiple-output (MIMO) antenna with a canonical two-port antenna that can be replicated and concatenated together to form MIMO antennas with arbitrary even numbers of ports.
Abstract: In this paper, we describe the design of a novel planar multiple-input-multiple-output (MIMO) antenna. The basic idea of the design is the development of a canonical two-port antenna that can be replicated and concatenated together to form MIMO antennas with arbitrary even numbers of ports. The design of the canonical element uses compact folded slots for the radiating elements but includes the use of field cancelation to enhance isolation by incorporating a coupling parasitic element. In addition by properly designing the coupling parasitic and the two-port antenna, coupling between canonical elements is also reduced allowing them to be concatenated together. The canonical element size is $27.5 \times 30\;{\rm mm}^2$ operating at 2.6 GHz and it can be packed together with high densities of up to 22 elements per square wavelength. To validate the design, results from 20-port planar printed MIMO antennas are presented operating at 2.6 GHz with a bandwidth of 100 MHz. The 20-port antenna has size of $1.3{\lambda}_{0} \times 0.69{\lambda}_{0}\;{\rm mm}^2$ providing an antenna density of 22 antenna in free space square wavelength ( ${\lambda}_{0}^{2}$ ). Even though the individual antennas are densely packed, all combinations of mutual couplings between ports exhibit better than 10 dB isolation. The antennas are printed on an FR-4 printed circuit board (PCB), which is a low-cost substrate and allows straightforward prototyping.
TL;DR: A printed antenna with frequency and pattern reconfiguration is presented in this letter to meet the requirements of IEEE 802.11a/b/g/n and 802.16 standards and provides a low-profile, low-cost, and reconfigurable solution for multistandard wireless communication applications.
Abstract: A printed antenna with frequency and pattern reconfiguration is presented in this letter to meet the requirements of IEEE 802.11a/b/g/n and 802.16 standards. By controlling five p-i-n diodes, the antenna can be considered as a planar monopole or a microstrip patch and has three operation modes, i.e. an omnidirectional pattern mode at the lower frequency band of 2.21–2.79 GHz, a unidirectional pattern mode at the higher frequency band of 5.27–5.56 GHz, and both of them working simultaneously. It provides a low-profile, low-cost, and reconfigurable solution for multistandard wireless communication applications.
TL;DR: In this paper, a new design approach for a microstrip patch antenna to achieve reconfigurable dual-band operation with tunable frequency ratio is introduced, which uses a lumped capacitor in the middle of a slotted patch antenna, which results in two resonant frequencies.
Abstract: A new design approach for a microstrip patch antenna to achieve reconfigurable dual-band operation with tunable frequency ratio is introduced. The approach uses a lumped capacitor in the middle of a slotted patch antenna, which results in two resonant frequencies. The two resonant frequencies and their ratio are functions of the capacitance value. If a varactor with an appropriate biasing network is used, electronic tuning is realized by changing the applied DC voltage. To understand the dual-resonance behavior of the proposed antenna, an equivalent circuit model based on the transmission line theory of the antenna is established, considering the slot effect and the lumped capacitor. The results are verified with full wave simulation. Furthermore, measurements for fabricated antenna prototypes operating in 2–4.5 GHz are carried out for validation, and the performance shows a tunable frequency ratio from 1.45 to 1.93 with a capacitance range from 0.31 to 0.74 pF. It is worthwhile to point out that the radiation patterns are similar at both bands because both resonances are due to the fundamental TM01 mode.
TL;DR: In this paper, a novel microstrip circular disc monopole antenna with a reconfigurable 10-dB impedance bandwidth is proposed in this communication for cognitive radios, which is fed by a microstrip line integrated with a bandpass filter based on a three-line coupled resonator (TLCR).
Abstract: A novel microstrip circular disc monopole antenna with a reconfigurable 10-dB impedance bandwidth is proposed in this communication for cognitive radios (CRs). The antenna is fed by a microstrip line integrated with a bandpass filter based on a three-line coupled resonator (TLCR). The reconfiguration of the filter enables the monopole antenna to operate at either a wideband state or a narrowband state by using a PIN diode. For the narrowband state, two varactor diodes are employed to change the antenna operating frequency from 3.9 to 4.82 GHz continuously, which is different from previous work using PIN diodes to realize a discrete tuning. Similar radiation patterns with low cross-polarization levels are achieved for the two operating states. Measured results on tuning range, radiation patterns, and realized gains are provided, which show good agreement with numerical simulations.
17 May 2015
TL;DR: In this article, a linearly polarized dual-band substrate integrated waveguide (SIW) antenna/array operating at Ka-band is proposed, where the antenna element consists of a SIW cavity with two longitudinal slots engraved in one of the conducting planes.
Abstract: The design of linearly polarized dual-band substrate integrated waveguide (SIW) antenna/array operating at Ka-band is proposed. The single antenna element consists of a SIW cavity with two longitudinal slots engraved in one of the conducting planes. The longer and shorter slots are resonating at 28 GHz and 38 GHz, respectively. Only the simulated results are presented. All simulations have been carried out using industry-standard software, CST Microwave Studio. For single antenna element, an impedance bandwidth (S11< −10 dB) of 0.45 GHz (1.60 %) and 2.20 GHz (5.8 %) is achieved with the maximum gain of 5.2 dBi and 5.9 dBi at 28 GHz and 38 GHz, respectively. To achieve high gain, a horizontally polarized linear array of four elements (1 × 4) is designed. For the antenna array, a microstrip lines feed network is designed using 3-dB wilkinson power divider. At 28 GHz and 38 GHz, the impedance bandwidth is 0.32 GHz (1.14 %) and 1.9 GHz (5%) having maximum gain of 11.9 dBi and 11.2 dBi, respectively. A low loss/cost substrate, RT/Duroid 5880 is used in the proposed designs.
TL;DR: In this article, a 3D printed microwave patch antenna is presented, which is fabricated by combining fused filament fabrication method for the dielectric part and ultrasonic metal wire mesh embedding approach for the conductor part.
Abstract: In this work, the design, fabrication and characterization of a 3-D printed microwave patch antenna is presented The antenna is fabricated by combining fused filament fabrication method for the dielectric part and ultrasonic metal wire mesh embedding approach for the conductor part Full wave finite-element simulations for different wire mesh structures and also the entire antenna have been done to make sure the embedded wire mesh has good performance at microwave frequency A microstrip patch antenna working around 75 GHz is printed and characterized to demonstrate the efficiency and accuracy of this technique The measured reflection coefficient shows a good resonance peak at 75 GHz The measured gain of this antenna is 55 dB at the resonance frequency Good agreement between simulation and measurement is obtained in both reflection coefficient and radiation pattern
TL;DR: In this article, a novel broadband RHCP/LHCP reconfigurable patch antenna array using an E-shaped patch antenna element was investigated, and a particle swarm optimization (PSO) was applied to achieve a combined bandwidth of 17% with good radiation pattern stability.
Abstract: A novel broadband RHCP/LHCP reconfigurable patch antenna array using an E-shaped patch antenna element is investigated. By applying particle swarm optimization (PSO), a challenging, combined $\mathbf{S}_{11}$ -AR bandwidth of 17% was achieved and verified through measurement for the isolated element using MEMS switches at an overall substrate thickness of $0.092 \boldsymbol{\lambda}_0$ . The achieved bandwidth is significantly higher than the current state-of-the-art in single-layer, single-feed circularly polarized (CP) patch element designs with similar substrate thickness. A small percentage of the upper frequency band experiences a pronounced beam squint similar to other thick substrate CP patch antennas. To overcome the beam squint, a novel rotated-element configuration is implemented to force pattern symmetry. Derivations of pattern symmetry and network effects are also shown. The final design prototype using rotated elements provides a measured 20% $\mathbf{S}_{11}$ -AR bandwidth with good radiation pattern stability.