Dual-polarized Microstrip Antenna Research Articles

A Compact Dual-Band Dual-Polarized Microstrip Antenna Array for MIMO-SAR Applications

This paper presents a compact dual-band dual-polarized microstrip antenna array with wide bandwidth and low profile for multiple-input multiple-output (MIMO) synthetic aperture radar- imagery applications where both high resolution and portability are required. This array has a stacked structure, consisting of two shared-aperture dual-band orthogonal-polarized sub-arrays with high isolation. Each pair of driven patches for the two-band shares two parasitic patches to achieve compactness. Slits are etched on the shared parasitic patches to adjust the coupling frequency between two elements of the two bands. The defected ground structure integrated in the array effectively suppresses H-plane cross-polarization. A $4\times6$ array as an MIMO element sized of 77 mm $\times79$ mm $\times2.2$ mm has been fabricated and tested. Both wide beamwidth and stable gain are achieved, where the impedance bandwidth of 27.7%, 30.6%, 15.6%, and 23.8% in X-band vertical, X-band horizontal, Ku-band vertical, and Ku-band horizontal polarizations, respectively.

A Novel Broadband and High-Isolation Dual-Polarized Microstrip Antenna Array Based on Quasi-Substrate Integrated Waveguide Technology

A $2 \times 2$ dual-polarized (DP) aperture-coupled microstrip antenna array with high isolation, broadband, and low cross polarization for Ku-band is proposed based on the quasi-substrate integrated waveguide (Q-SIW) technology. The proposed microstrip antenna array is excited by two orthogonal four-way corporate (parallel) feed networks, which not only has a multistage structure with broadband but also provides pairs of differential outputs. The Q-SIW structure, composed of several reflectors and substrate integrated metal pillars, is used to increase the bandwidth, improve the isolation, and reduce the influence of feed network. The measured and simulated results show that the DP array exhibits an impedance bandwidth of 26.37% for vertical port and 27.77% for horizontal port. The cross polarization level is better than −34 dB and −40 dB for two ports, and the isolation between the two ports is above 32 dB.

A High-Gain Transmitarray for Generating Dual-Mode OAM Beams

This paper proposes a novel transmitarray antenna which can achieve high gain and produce dual-mode orbital angular momentum (OAM) beams in Ku -band. Two back-to-back wideband dual-polarized microstrip antennas are employed as the unit cells, which are connected using metalized via holes. Full 360° phase ranges can be obtained by varying the length of feeding lines in two orthogonal polarizations. Due to high isolation between the two orthogonal polarizations, dual-mode OAM beams can be formed simultaneously by tuning phase distributions in x- and y-polarizations, respectively. The approach for generating OAM beams is explained. To verify this concept, one prototype carrying 0 and +1 mode OAM beams is designed, fabricated, and measured. Experimental results demonstrate that both 0 and +1 mode OAM beams can be generated successfully, and the measured results agree well with the simulated results. Because of high directivity and focusing effects of transmitarray, the proposed +1 mode OAM beam has stable performance at a long propagation distance. The maximum gain reaches 26 and 20 dBi in 0 and +1 mode OAM beams, respectively. Meanwhile, a narrow divergence angle of ±5° is obtained in +1 mode OAM beam. Compared with other OAM antennas reported, main advantages of the proposed antenna include high gain, narrow divergence angle, low cost, planar structure, and the capability of producing dual-mode OAM beams.

Design of a dual linear polarization antenna using split ring resonators at X-band

Abstract. Dual linear polarization microstrip antenna configurations are very suitable for high-performance satellites, wireless communication and radar applications. This paper presents a new method to improve the co-cross polarization discrimination (XPD) for dual linear polarized microstrip antennas at 10 GHz. For this, three various configurations of a dual linear polarization antenna utilizing metamaterial unit cells are shown. In the first layout, the microstrip patch antenna is loaded with two pairs of spiral ring resonators, in the second model, a split ring resonator is placed between two microstrip feed lines, and in the third design, a complementary split ring resonators are etched in the ground plane. This work has two primary goals: the first is related to the addition of metamaterial unit cells to the antenna structure which permits compensation for an asymmetric current distribution flow on the microstrip antenna and thus yields a symmetrical current distribution on it. This compensation leads to an important enhancement in the XPD in comparison to a conventional dual linear polarized microstrip patch antenna. The simulation reveals an improvement of 7.9, 8.8, and 4 dB in the E and H planes for the three designs, respectively, in the XPD as compared to the conventional dual linear polarized patch antenna. The second objective of this paper is to present the characteristics and performances of the designs of the spiral ring resonator (S-RR), split ring resonator (SRR), and complementary split ring resonator (CSRR) metamaterial unit cells. The simulations are evaluated using the commercial full-wave simulator, Ansoft High-Frequency Structure Simulator (HFSS).

Harmonic suppression of a dual-polarized microstrip array by using microstrip stubs

A compact dual-polarized two-element microstrip antenna array has been designed at 3.5 GHz frequency band and the higher order modes up to second harmonics have been successfully suppressed for two orthogonal modes. Two pairs of microstrip stubs of electrical lengths λg1/4 (λg1 = wavelength of 1st harmonic signal) and λg2/8 (λg2 = wavelength of 2nd harmonic signal) respectively have been integrated with the microstrip feed line and two harmonics and a sub-harmonic of the fundamental mode have been reduced. The design offers a port isolation of more than 23 dB over the operating band and the measured bandwidths of the two polarizations of 250 and 275 MHz, respectively, are reported. Simulated and measured results show that the harmonic components exist at 7.05 GHz (1st harmonic, TM20), 10.45 GHz (2nd harmonic, TM30) and also a sub-harmonics at 5.5 GHz (TM12 of the fundamental frequency have been successfully suppressed. The harmonic properties of microstrip antenna with and without stubs have been studied and the result indicates that the harmonic components of the array for two orthogonal polarizations have been well eliminated because of the effect of the tuning stubs. To validate the concept the prototypes were fabricated, tested and compared with the simulated results.

Extremely low-profile wideband dual-polarized microstrip antenna for micro-base-station applications

Extremely low-profile wideband dual-polarized microstrip antenna for micro-base-station applications

A Wideband Differential-Fed Dual-Polarized Microstrip Antenna Under Radiation of Dual Improved Odd-Order Resonant Modes

A low profile differential-fed dual-polarized microstrip patch antenna (MPA) with bandwidth enhancement is proposed under radiation of the first and second odd-order resonant modes. First, all of even-order modes are fully suppressed by using a differentially feeding scheme instead of the single probe feed. Next, the radiation pattern of a square MPA is theoretically analyzed. It is demonstrated that the traditional monopole-like radiation of the second odd-order mode in the H-plane, i.e., TM21 mode, can be transformed into the broadside radiation by etching out a narrow slot at the center of the radiating patch. After that, an array of shorting pins is symmetrically embedded underneath the radiating patch so as to progressively push up the resonant frequency of the TM01 mode (or TM10 mode), while almost maintaining that of TM21 mode (or TM12 mode) to be unchanged. With these arrangements, a wide impedance bandwidth with stable radiation peak in the broadside direction is achieved for the MPA under this dual modes operation. Finally, the dual-polarized MPA is fabricated and measured. The measured results are found in good agreement with the simulated ones in terms of the reflection coefficient, radiation pattern, and realized gain, demonstrating that the MPA’s impedance bandwidth ( $\vert S_{\mathrm { {dd11}}}\vert dB) is tremendously increased up to about 8% with a high differential port-to-port isolation of better than 22.6 dB. In particular, a low profile property of about 0.024 free-space wavelength and the stable radiation pattern are also achieved.

Ka-band antenna arrays with dual-frequency and dual-polarized patch elements

In this contribution a dual-band, dual-polarized microstrip antenna element for array applications is presented. The patch antenna is designed to operate simultaneously at around 30 and 20 GHz, the up- and downlink frequencies of modern Ka-band satellite communication systems. The antenna is smaller than half the freespace wavelength at 30 GHz to enable its utilization as array element of dual-band ground terminals. Integrating transmitter and receiver circuits allows, in turn, for a very compact active terminal solution. To minimize production cost, the design is carried out in standard multilayer printed circuit board technology. The antenna features two distinct polarization ports suitable for either dual linear or dual circular polarization if both ports are excited in quadrature. The single antenna design process is described in detail and simulation and measurement results are presented. Finally, different arrays based on this patch antenna are evaluated by simulation and measurements.

Design of Dual-Band and Dual-Polarized Microstrip Antenna for Applications on HAPs

This paper presents the design of a dual-band microstrip antenna with dual polarization characteristic for high altitude platforms (HAPs). The antenna has two isolated ports and is suitable for terminals with receiving and transmitting functions operating simultaneously. The element is designed for operation at 5.8 and 7 GHz with 100 MHz bandwidth in each band. The antenna geometry and its main design parameters are presented and discussed in the paper. Numerical and experimental results show that this radiator exhibits good performance in terms of impedance matching and circular polarization purity.

A broadband proximity-coupled dual-polarized microstrip antenna with L-shape backed cavity for X-band applications

A broadband proximity-coupled dual-polarized microstrip antenna with a L-shape backed cavity is presented. The L-shape cavity backed ground plane is used to enhance the feeding coupling and thus to broaden the bandwidth of this antenna. The parameter study is done in detail to show the guideline of designing this antenna. A prototype antenna with optimized parameters is designed and fabricated. Simulation and measurement results show that the proposed design achieves S11≤−10dB bandwidth of more than 30% (8.2–11.4GHz) and the port isolation is larger than 20dB over that band. This antenna has a relatively simple structure, and can be directly mounted on the metal body surface in application.

H-커플링 슬롯 광대역 이중편파 마이크로스트립 안테나

본 논문에서는 H-형 커플링 슬롯을 가진 광대역 이중 편파 마이크로스트립 안테나를 제안하였다. 제안된 안테나는 통신사업자들이 경쟁적으로 공공장소에 구축하고 있는 hot-spot zone과 같은 제한된 장소에서 많은 통신 단말기가 동시에 사용되면 상호 간섭이나 다중경로 페이딩에 의한 전송품질의 열화 발생을 방지할 수 있다. 설계된 안테나는 2.7GHz 이하의 주파수 대역에서 33.98%의 임피던스 대역폭(<TEX>$SWR{\leq}2$</TEX>)과 8.58 dBi (at 2.11 GHz)의 최대 이득을 갖는 것을 측정결과를 통하여 확인하였다. 제안된 안테나는 단순한 구조로 다중 주파수 대역을 수용할 수 있으며 다양한 상업적인 적용이 가능하도록 대량생산의 장점을 갖는다. This paper investigates wideband dual-polarized microstrip antenna with H-shaped coupling slot. These types of antennas are used to prevent deterioration of transmission quality caused by terminal interference or multipath fading, which usually occur when many terminals are used in limited space such as hot-spot zones. The experimental results show that the impedance bandwidth (<TEX>$SWR{\leq}2$</TEX>) of 33.98% and the peak gain of 8.58 dBi (at 2.11 GHz) were obtained by the frequency band under 2.7 GHz. The proposed antenna is designed originally for multiple service bands with simple structure and easily be mass-produced for various commercial applications.

Slot antenna for mobile base station using AMC

In this paper, a new configuration of dual-band, dual-polarized microstrip antenna applicable to mobile base stations is proposed. The concept behind the new design is the use of an artificial magnetic conductor (AMC) structure that operates in the required two bands beneath a radiating diamond shaped slot. The choice of the diamond-shaped slot is due to its support of an infinite number of resonant modes where the dimensions of the diamond shape have more degree of freedom that controls the excited modes when compared to the rectangular slot. The proposed antenna works over the 870–960 MHz (GSM850/GSM900) band and the 1710–2170 MHz (DCS1800/PCS1900/UMTS2100) bands for mobile communication systems. The antenna is suitable for transmitting and receiving mobile signals since it has two ports of orthogonal polarization. The antenna is fabricated on a combination of FR4 dielectric substrate and foam layers in order to achieve low cost. The proposed antenna yields high isolation between its two ports not exceeding −30 dB and a front-to-back ratio exceeding 15 dB. The average antenna gains are about 6.6 dBi at the GSM850/GSM900, 7.1 dBi at the DCS1800/PCS1900, and 6.8 dBi at the UMTS2100 bands. The theory of radiation is proved analytically and verified by comparing its results with some simulated results. Finally, a good agreement between the simulated and measured results is noticed.

Broadband and High-Isolation Dual-Polarized Microstrip Antenna With Low Radar Cross Section

A Ku-band dual-linear polarized broadband aperture-coupled antenna with high-isolation and low radar cross section (RCS) in special direction is presented, fabricated, and measured based on substrate integrated waveguide technology. The substrate-integrated rows of metallized via holes (SIRMHs) are inserted into the conventional aperture-coupled antenna to enhance the isolation and improve the impedance matching. Monostatic RCS is reduced because the surface current of the metallized ground plane is guided by the SIRMHs. The theoretical and experimental results are in good agreement. Experimental results indicated that the isolation is more than 40 dB, the bandwidth obtains 21% of return loss less than -20 dB, and the RCS is reduced to as much as 23 dB from 12.2 to 16 GHz compared to a traditional antenna when incident angle is 30 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> .

DESIGN OF DUAL-FEED DUAL-POLARIZED MICROSTRIP ANTENNA WITH HIGH ISOLATION AND LOW CROSS POLARIZATION

A broadband dual-feed dual-polarized microstrip antenna with low cross polarization and high isolation is presented. The dual- orthogonal linearly polarized mode is excited by two difierent feed mechanisms from a single circular radiating patch. One of the two modes is excited by a pair of L-shaped probes with a 180 - phase difierences, and the other is excited by an H-shaped aperture. The proposed design has a very simple antenna structure with a wide input impedance bandwidth (23.25% for Port 1 and 35% for Port 2) and also its two input port isolation is found to be as low as i40dB. Measured results of the fabricated antenna prototypes are also carried out to verify the simulation analysis.

Design and Simulation of a Broad Band Retrodirective Array Element

In this paper, a novel dual-polarized antenna fed by microstrip line for retrodirective array is presented. The star-shaped patch is used to reduce the mutual coupling among array elements; also bandwidth can be enhanced by choosing stacked patch. The simulated results indicate that the impedance bandwidth (VSWR&lt;2) achieve 17%, the antenna gain is higher than 8dB, the port-to-port isolation and polarization isolation maintain at less than-20dB. A 1-D retrodirective array is designed based on this novel element, the array displays better retrodirectivity. It is validated that the dual-polarized microstrip antenna can be widely used in retrodirective array.

Single-Feed Dual-Band Dual-Linearly-Polarized Proximity-Coupled Patch Antenna

In this paper, two novel single-feed dual-band dual-polarized microstrip antennas, fed by proximity coupling, are presented. The first approach begins with a new patch antenna that provides dual-band dual-polarized operation by means of an open-circuit stub, added at the open end of the feed line. By adding a stub to the end of the feed line, one can make an antenna with two resonant frequencies. The first resonant frequency is approximately the same as that in the initial design, but the second frequency depends on the stub's length, the stub's location, and the location of the feed point across the patch's width. Moreover, the variation of the feed-line location with respect to the patch's length has no significant effect on the first resonance frequency, while the second frequency changes. The second approach that is studied to realize a dual-band dual-polarized design utilizes a microstrip-gap proximity-coupled feed mechanism. Further insight is sought through the investigation of the surface-current densities on the proposed patch antennas at their resonant frequencies. The radiation performance - including radiation pattern, cross polarization, and gain - is satisfactory within two bands. The CST simulation results and measurement results showed good agreement with each other.

Development of Shared Aperture Dual Polarized Microstrip Antenna at L-Band

A simple technique to develop dual feed dual linearly polarized aperture coupled planar microstrip patch antenna at L-band frequency has been presented. A 4 × 2 array of aperture coupled square resonant patch antenna has been designed, fabricated and tested. The design optimization is carried out using commercial method of moment (MoM) based simulation software. The inter element spacing, inter-layer separation, isolation between the feeding ports, and other associated antenna parameters are optimized by successive simulations using the commercial software. Measured gain is better than 14 dBi. Measured results are also presented.

Single-Feed Dual-Band Dual-Mode and Dual-Polarized Microstrip Antenna based on Metamaterial Structure

A novel single-feed dual-band dual-mode and dual-polarized microstrip antenna based on metamaterial structure is proposed. The composite right/left-handed transmission line (CRLH TL) theory is used to design this antenna. Dual-mode can be obtained by exciting the antenna with a monopolar radiation in the n = 0 mode and a patch-like radiation pattern in the n = +1 mode, respectively. As the geometry of the radiating patch does not affect the infinite wavelength mode, circular polarization (CP) is obtained for the n = +1 mode by truncating the square radiating patch with the n = 0 mode, linear polarization (LP) staying unchangeable. Results of a fabricated one illustrate that this antenna is valuable in practical application for its low-profile, easy fabrication, radiation pattern selectivity and polarized diversity.

Dual Polarized Array Antenna for S/X Band Active Phased Array Radar Application

A dual-band dual-polarized microstrip antenna array for an advanced multi-function radio function concept (AMRFC) radar application operating at S and X-bands is proposed. Two stacked planar arrays with three different thin substrates (RT/Duroid 5880 substrates with e r =2.2 and three different thicknesses of 0.253 ㎜, 0.508 ㎜ and 0.762 ㎜) are integrated to provide simultaneous operation at S band (3～3.3 ㎓) and X band (9～11 ㎓). To allow similar scan ranges for both bands, the S-band elements are selected as perforated patches to enable the placement of the X-band elements within them. Square patches are used as the radiating elements for the X-band. Good agreement exists between the simulated and the measured results. The measured impedance bandwidth (VSWR≤2) of the prototype array reaches 9.5 % and 25 % for the S- and X-bands, respectively. The measured isolation between the two orthogonal polarizations for both bands is better than 15 ㏈. The measured cross-polarization level is ≤?21 ㏈ for the S-band and ≤?20 ㏈ for the X-band.

Dual-Feed Dual-Polarized Patch Antenna With Low Cross Polarization and High Isolation

A dual-feed dual-polarized microstrip antenna with low cross polarization and high isolation is experimentally studied. Two different feed mechanisms are designed to excite a dual orthogonal linearly-polarized mode from a single radiating patch. One of the two modes is excited by an aperture-coupled feed, which is comprised of a compact resonant annular-ring slot and a T-shaped microstrip feed line; while the other is excited by a pair of meandering strips with a 180deg phase differences. Both the linearly-polarized modes are designed to operate at 2400 MHz frequency band, and from the measured results, it is found that the isolation between the two feeding ports is less than 40 dB across a 10 dB-input-impedance bandwidth of 14%. In addition, low cross polarization is observed from the radiation patterns of the two modes, especially at the broadside direction. Simulation analyses are also carried out to support the measured results.