Dual-polarized Microstrip Research Articles

Dual-Band Dual-Polarized Microstrip Antenna Array Using Double-Layer Gridded Patches for 5G Millimeter-Wave Applications

This article presents a dual-band and dual-polarized microstrip antenna array with broadside beam scanning ability for millimeter-wave applications. Within a compact multilayer structure, wide bandwidth and high port isolation are achieved by using double-layer gridded patches with three groups of metallic via-fences. For beam scanning purpose, a prototype of <inline-formula> <tex-math notation="LaTeX">$2 \times 2$ </tex-math></inline-formula> array is designed, fabricated, and tested. The experimental results agree well with the simulations. For both orthogonal polarizations, the &#x2212;10 dB bandwidth covers 23.3&#x2013;31.7 and 42.5&#x2013;46.5 GHz with average gains of 12 and 13.1 dBi, respectively. A 3 dB beam scanning angle from &#x2212;51&#x00B0; to 43&#x00B0; at 27 GHz and &#x2212;28&#x00B0; to 30&#x00B0; at 45 GHz is obtained. The proposed array provides dual-band and wideband properties for dual orthogonal polarizations with competitive beam steering range and compact dimensions, as a feasible solution for fifth-generation (5G) millimeter-wave mobile communications.

A High Isolation Dual-Polarized Microstrip Antenna for Sub-6 GHz Base Station

A dual-polarized microstrip antenna with high isolation for Sub-6 GHz (3.4- 3.6 GHz) base station application is presented in this letter. To increase isolation between two feed ports, the stacked patches are excited by double orthogonal open-ended feed lines. The proposed antenna is simulated by HFSS18.0. The simulation results show that the isolation is better than 50 dB over the whole bandwidth from 3.23 to 3.85 GHz with the cross-polarization levels less than - 30 dB when the gains are higher than 7.64 dBi for dual polarization. It’s valuable for this design method to devise mobile communication system base station antenna used in Sub-6 GHz of China Unicom and China Telecom.

Dual Polarization MIMO Antenna for 5G Mobile Phone Applications

A dual-polarization microstrip multiple-input-multiple-output (MIMO) antenna for 5G mobile phone applications is proposed in this communication. Eight differentially fed microstrip antenna elements are arranged on the back cover of a mobile phone. Four shorted radiation patches constitute the radiator of an antenna pair, and four antenna pairs form an eight-element MIMO antenna. The antenna element can excite two modes by utilizing the interaction of the two elements of one antenna pair and has a wide operating band. A prototype of the MIMO antenna is fabricated, and eight power dividers are applied to provide the differential feeding. The measured −6 dB impedance operating band is 4.37–5.5 GHz and can cover the N79 band (4.4–5 GHz) for 5G. The measured efficiencies of the antenna elements with a low profile of 1.2 mm are 40%–50% in the N79 band though the substrate has a high loss tangent of 0.02. The measured results show that the MIMO antenna has low mutual couplings of lower than −22 dB, low envelope correlation coefficients (ECCs) of lower than 0.068, and the ratios of mean effective gains (MEGs) of lower than 2.28 dB. Some issues in practical applications are discussed. The proposed antenna provides a promising solution to design a compact and pony-size MIMO antenna without occupying the inner space or ground clearance of a mobile phone.

Dual-Polarized Microstrip Antennas With Capacitive via Fence for Wide Beamwidth and High Isolation

A dual-polarized microstrip antenna loaded with capacitive via fence is proposed for compact size, wide beamwidth, and high isolation. By exploring a capacitive blind-via fence near the radiating apertures, the field is concentrated between the fence and ground, achieving obvious dimension miniaturization and wide beamwidth for regular dual-polarized microstrip antennas. The proposed blind-via fence is constituted by four rows of metallic wires with subwavelength diameter, period, and gap to the ground. Thanks to the field concentration brought by the blind-via fence, high isolation is realized by suppressing the radiation from the feeding probes, similar to two disk-loaded monopole antennas, and forcing the fundamental mode of the patch. To validate the proposed concept, a prototype is fabricated and characterized with the size of 0.19 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> × 0.19 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> × 0.07λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> (λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> is the free-space wavelength at the center frequency). The simulated and measured results agree well, with wide half-power beamwidth of 107° and 105° in the Eand H-planes, respectively. Meanwhile, the port isolation is higher than 32 dB within the operating bandwidth of 2.48-2.56 GHz. The proposed antenna is with the merits of compact size, wide beamwidth, and high isolation, exhibiting potential usage in diversity or multiple-input and multiple-output (MIMO) systems with wide-coverage applications.

Dual Wide Band Circularly Polarized Microstrip Patch Antenna with Offset Feed

Dual Wide Band Circularly Polarized Microstrip Patch Antenna with Offset Feed

Dual-Polarized Perpendicularly Fed Balanced Feed Antenna With High Polarization Purity

The design and analysis of a high-performance dual-polarized perpendicularly fed microstrip patch antenna are presented. The planar balanced feeding technique has been evolved to a highly isolated nonplanar method for exciting a dual-polarized microstrip patch antenna. Reducing the number of parallel dielectric and ground plane layers improves the isolation between polarization and increases the antenna scan capability. The simulation and measurement results of the proposed antenna are presented. The proposed antenna possesses high-performance electromagnetic characteristics. Input isolation of better than 52 dB between orthogonal polarizations in the entire frequency band of 2.7-2.9 GHz and cross-polarization level of better than -32 dB have been achieved in the measured results.

Optimal design of a large dual-polarization microstrip reflectarray with China-coverage patterns for satellite communications

A large dual-polarization microstrip reflectarray with China-coverage patterns in two operating bands is designed. To sufficiently compensate for the spatial phase delay differences in two operating bands separately, a three-layer rectangular patch element is addressed, which is suitable for the large dual-polarization reflectarray. Due to the complexly shaped areas and high gain requirements, there are more than 25 000 elements in the reflectarray, making it difficult to design, due to more than 150 000 optimization variables. First, the discrete fast Fourier transform (DFFT) and the inverse DFFT are used to establish a one-to-one relationship between the aperture distribution and the far field, which lays a foundation for optimizing the shaped-beam reflectarray. The intersection approach, based on the alternating projection, is used to obtain the desired reflection phases of all the elements at some sample frequencies, and a new method for producing a suitable initial solution is proposed to avoid undesired local minima. To validate the design method, a dual-polarization shaped-beam reflectarray with 7569 elements is fabricated and measured. The measurement results are in reasonable agreement with the simulation ones. Then, for the large broadband reflectarray with the minimum differential spatial phase delays in the operating band, an approach for determining the optimal position of the feed is discussed. To simultaneously find optimal dimensions of each element in two orthogonal directions, we establish a new optimization model, which is solved by the regular polyhedron method. Finally, a dual-band dual-polarization microstrip reflectarray with 25 305 elements is designed to cover the continent of China. Simulation results show that patterns of the reflectarray meet the China-coverage requirements in two operating bands, and that the proposed optimization method for designing large reflectarrays with complexly shaped patterns is reliable and efficient.

A Method for Radiation Pattern Reconstruction of Phased-Array Antenna

In this letter, we propose an approach for reconstructing the radiation pattern of a phased-array antenna by application of the minimum norm least-square solution. Compared with conventional methods, our construction process only requires fewer beam patterns and distortion is also largely mitigated by compensating the mutual coupling between the elements in the antenna. Our approach has low reconstruction error for the copolar and cross-polar patterns while being valid for a large scanning range. Moreover, we design a dual-polarization microstrip patch array antenna to test the effectiveness of the proposed method.

Cross-Polarization Suppression of a Dual-Polarized Microstrip Antenna Using Enclosed Substrate-Integrated Cavities

An enclosed substrate-integrated cavities (ESICs) backed dual-polarized (DP) array with suppressed cross polarization for an X-band radar is investigated. Initially, stacked patches and cross aperture-coupled technique are utilized to achieve a wideband impedance matching and a DP operation. Additionally, a couple of multistage corporate feed networks based on the pairwise anti-phase feed technique are employed to suppress cross polarization over the operating band. Finally, five ESICs are inserted into the array to further suppress the cross polarization. A prototype of array is fabricated and measured. The measured results show that the DP array yields fractional bandwidths (VSWR ≤ 2) of 29.89% for Port H and 30.73% for Port V. The cross-polarization levels are better than –42 dB for V-pol and –44 dB for H-pol at 9.6 GHz, and the isolation between two ports remains above 39 dB over the whole operating bandwidth.

Linear array of dual‐polarised slot‐coupled dielectric‐rod elements for wireless applications

The design of a dual-polarised series-fed microstrip array antenna for wireless applications, especially in the 5150–5750 MHz band, is delineated in this study, which consists of 12 dielectric rods, fed by circular slots. The rod height can be exploited to improve antenna gain and control its azimuth beamwidth. Using circular slot elements with a central crossing point improves port isolation and cross polarisation. The array elements are fed via two series-fed six-element arms having 25 dB Taylor distribution in each polarisation. The given arms are fed from the centre. Regarding H-polarisation, the arms are fed with a 180° phase shift to improve isolation between the ports as well as the cross polarisation. Additionally, a reflector plane is placed behind the array to suppress back-lobe radiation. A prototype of the array antenna is fabricated and measured. The return loss of the antenna is over 10 dB, varying from 5.1 to 5.8 GHz, and the isolation exceeds 30 dB over the bandwidth. The measured and simulated patterns are presented for both polarisations.

Design and evaluation of a wideband reflectarray antenna using cross dipole with double‐ring elements

This article reports the design and analysis of a wideband, single layer, and dual-polarized microstrip reflectarray for Ku-band applications. The array element is constructed using a crossed dipole enclosed by two cross dipole loops. The element is optimized to exhibit a linear phase response and wide reflection phase range. The reflection characteristic of the unit cell is analyzed using an infinite array approach and the results are presented. A 324-element Ku-band microstrip reflectarray antenna of size 20 × 20 cm2 is simulated, fabricated, and experimentally evaluated. The 2.9-dB gain-bandwidth and aperture efficiency of the reported reflectarray are 45.3% and 35%, respectively. The reflectarray operates in the frequency range of 10.6 to 16.8 GHz.

High gain dual-polarised pentagonal microstrip antenna for wireless communications

In this paper we propose a dual polarised pentagonal microstrip antenna for massive MIMO-base station to operate at 2.4 GHz WLAN band (IEEE 802.11 b/g/n/ax). The various researchers have used antenna array with different feeds for the massive MIMO BS to obtain the desired gain with required impedance bandwidth. However, this proposed work contradicts with existing method by using a single novel radiating element with suspended substrate to achieve the desired gain and required impedance bandwidth. The circular polarisation is achieved by using two coaxial-probe feeds. The main focus of research is on the selection of proper shape of the radiating element for Massive MIMO BS. The proposed antenna is successfully simulated using HFSS 13.0, fabricated on a FR-4 substrate and measured. The proposed antenna exhibits a much higher gain of 6.17 dB, improved impedance bandwidth of 171.9 MHz (return loss, S11=−10 dB), the axial ratio (AR) is 1.78 dB (< 3 dB), the patch area of 1,775 mm2, and also yields return loss better than −15 dB around the centre frequency of 2.45 GHz. The measured characteristics of the antenna are in good agreement with the simulated results.

Design of Compact Dual Band Circular Polarized Micro-strip Antenna for High Efficiency WLAN 802.11ax-2019

Design of antennas for the latest upcoming standards of WLANs is considered as a key challenge in the science of Mobile Communication Engineering. Micro strip antennas are supposed to have some quality features in mobile and wireless network systems. Their weight and size are reduced and they are capable of having low power capacity. All these interesting features enabled these type of antennas suitable for the communication of IEEE 802.11ax-2019 high speed WLANs. Shape of these antennas can be designed in an efficient manner to achieve required gain and bandwidth. In this paper the concept of circular polarization has been introduced along with compact design of antennas in order to achieve return loss and axial ratio of less than -10 dB and 3dB respectively. Antenna has been designed and simulated on CST MW studio software and usage of dual bands 2.4 and 5.2GHz having circular polarization is properly elucidated for 802.11ax-2019.

Design of Compact Dual Band Circular Polarized Micro-strip Antenna for High Efficiency WLAN 802.11ax-2019

Design of Compact Dual Band Circular Polarized Micro-strip Antenna for High Efficiency WLAN 802.11ax-2019

Dual Linearly Polarized Microstrip Antenna Using a Slot-Loaded TM50 Mode

We present a high-gain, low-profile dual-polarized microstrip antenna operating in the hybridized higher order mode. The proposed antenna consists of a slot-loaded cross-shaped patch, which can be considered as orthogonally polarized radiating elements operated in the TM50 mode. Moreover, the four loaded slots can effectively excite the in-phase TM10 mode such that the superposition of both modes can lead to gain enhancement in the broadside direction, with suppressed sidelobes. The proposed antenna requires only a single-dielectric layer and a simple feeding method, while exhibiting good isolation between the two polarizations. We have developed a prototype, which has a total size of only 1.65 λ0 × 1.65 λ0 × 0.04 λ0 (λ0 is the free-space wavelength at the center frequency) and a measured maximum gain of 10.9 dBi. This dual-polarized microstrip antenna with the advantages of high gain, low profile, low cost, and good isolation, is envisioned to benefit many multiple-input, multiple-output and the fifth generation (5G) communication systems.

Design, fabrication, and test of a novel broadband dual-polarized microstrip antenna for WLAN applications

AbstractA dual-polarized dual-layer wideband microstrip antenna is presented. Dual orthogonal linear polarization and enhanced isolation between two ports are achieved by employing two radiating patches perpendicular to each other and printed on two separate substrates. Broadband behavior of the antenna is realized by using two wideband double-sided printed strip dipole and angular ring as radiating patches along with wideband baluns as feeding system. The patches are connected to baluns with two separate twin-lead transmission lines. Moreover, to improve the impedance bandwidth of the strip dipole significantly, a diamond-shape parasitic patch is artily incorporated into the top side of the upper layer of the antenna. The proposed antenna can easily be employed in large-scale arrays thanks to the feeding system of the patches. A prototype is fabricated to verify the simulation results where the measurement results show the −10 dB impedance bandwidths of 40% (4.3–6.5 GHz) and 43% (4.2–6.5 GHz) at port #1 and port #2, respectively. Besides, the isolation between two ports and the radiation gain are obtained around 35 dB and 9 dBi, respectively, which are useful for WLAN applications.

Dual-polarized lens antenna based on multimode metasurfaces**Project supported by the Open Research Program of the State Key Laboratory of Millimeter Waves, China (Grant No. K201926), the Postgraduate Research & Practice Innovation Program of Jiangsu Province, China, and the Nanjing University of Posts and Telecommunications Scientific Foundation, China (Grant No. NY215137).

We propose a dual-polarized lens antenna system based on isotropic metasurfaces for 12 GHz applications. The metasurface lens is composed of subwavelength unit cells (0.24λ0) with metallic strips etched on the top and bottom sides of the unit cell, and a cross-slots metallic layer in the middle that serves as the ground. The multimode resonance in the unit cell can realize a large phase shift (covering 0°–360°), and the total transmission efficiency of the lens is above 80%. The feed antenna at the focal point of the lens is a broadband dual-polarized microstrip antenna. Both the simulated and the measured results demonstrate that the dual-polarized lens antenna system can realize a gain of more than 16.1 dB, and an input port isolation of more than 25.0 dB.

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.

Double-Differential-Fed, Dual-Polarized Patch Antenna With 90 dB Interport RF Isolation for a 2.4 GHz In-Band Full-Duplex Transceiver

This letter presents a 2.4 GHz, dual-polarized microstrip patch antenna with extremely high interport isolation for a shared antenna architecture-based in-band full-duplex transceiver. The presented antenna configuration is based on four-ports linearly polarized single radiating element with differential feeding for both transmit $(T_{x})$ and receive $(R_{x})$ operation. The double-differential feeding using two identical 3 dB/180° ring hybrid couplers with nice amplitude and phase balance effectively suppresses the interport RF leakage to achieve very high isolation. The prototype of the proposed antenna architecture is implemented using a 1.6 mm thick general-purpose FR-4 substrate. The implemented antenna provides more than 90 and 80 dB interport RF isolation for 20 and 40 MHz bandwidths, respectively, in addition to more than 98 dB port-to-port peak isolation when measured inside an anechoic chamber. To the best of our knowledge, this is the highest amount of RF isolation reported for a single dual-polarized patch antenna.