Dual-polarized Planar Antenna Research Articles

Low-Profile Planar Ultrawideband Modular Antenna Array Loaded With Parasitic Metal Strips

A low-profile dual-polarized planar ultrawideband modular antenna (PUMA) array is proposed in this paper. The overall profile is as small as 11.4 mm (0.228λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>high</i></sub> , where λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>high</i></sub> is the free-space wavelength at the highest operating frequency) based on element sizes 25 × 25 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> (0.5 × 0.5λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>high</i></sub> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) and a large operating frequency bandwidth achieved by loading lossless parasitic metal strips between the dipole patch and the ground plane. The loop-mode resonance that causes deterioration of the port isolation around the lowest operating frequency is comprehensively analyzed and suppression methods are proposed. To further reduce the overall profile, a metasurface-based wide-angle impedance matching (MS-WAIM) layer is introduced. The surface waves guided by the MS-WAIM layer during wide-angle scanning in H-plane are suppressed by cutting properly-sized square holes at critical positions. The calculated results show that the proposed infinite array can scan up to ±60° in E/H-planes with active VSWRs below 2.9 within 2–6 GHz and orthogonal port isolations beyond 20 dB. A 12 × 11 array prototype is fabricated and reasonable agreement is achieved between the calculated and measured results.

A novel Ultra-wideband Wide-angle scanning Dual-polarized antenna with multilayer dielectric

In this paper, a dual-polarized planar ultra-wideband modular antenna (PUMA) with wide-scanning angle matching layers is proposed. The multiple dielectric layers and frequency selective surfaces (FSS) are loaded on the dipoles. Each frequency selective surface is etched on the dielectric plate as one wide-angle -matching layer. By applying three wide-angle-matching layers, the wide-scanning angle performance is guaranteed. As for the ultra-wideband performance, a metal cylinder is added to the lower space between adjacent dipoles, and the upper end of the cylinder has a certain distance from the dipole. This forms a “ridge” structure which shift problematic common-mode resonances caused by circulating current out of band. A dual-polarized 256-port array (16×16) is set and simulated. The simulation result indicates that the proposed antenna operating over 4.79GHz -20.15GHz (4.20:1) achieves VSWR<3 while scanning to 60° in E-plane and D-plane, and to 45° in H-plane respectively.

Design of broadband dual‐polarized planar antenna with triple radiators

A wideband dual-polarized planar antenna with triple radiators is proposed for the LTE600/LTE700/GSM850/GSM900 base station in this paper. A novel concept of multi-radiator for multi-resonance by close coupling feed is presented and analysed . The proposed antenna is mainly composed of two pairs of loop dipole, L-shaped radiator, step dipole, two L-shaped feed lines, balun and reflector. The reflector is designed with a centrosymmetric partible baffle for directional radiations, which contribute to stable radiations as well. Owing to the novel closely coupling scheme for multi-radiators, three resonances are simultaneously excited within the desired band, producing a wide bandwidth of 47.7% (from 0.59 to 0.96 GHz) for |S11| < −15 dB with high isolation more than 30 dB. Moreover, an average gain of 8.8 dBi as well as stable radiation patterns are achieved simultaneously.

A Miniaturized Wideband Dual-Polarized Planar Antenna Based on Multiresonance

In this letter, a miniaturized wideband dual-polarized antenna with a simple structure is proposed. The proposed antenna includes two stacked square loops, which are positioned around the cross-dipole, these loops are utilized to introduce a new resonant mode at a relatively low frequency band, which essentially widens the impedance bandwidth and realizes the miniaturization design. It also includes metallic plates that are vertically positioned on the reflector. These parasitic vertical metallic plates, operating in coincidence with the coupling energy from the nearby radiators, serve to generate an additional resonant mode outside the original impedance passband of the cross-dipole antenna. This enables further expansion of the impedance bandwidth. A prototype was fabricated and tested, where the measured results demonstrated that the proposed antenna ability to achieve a wide impedance bandwidth, i.e., up to 91% (0.98 to 2.6 GHz) with VSWR <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$ &lt; $</tex-math></inline-formula> 2. Additionally, the isolation between the two linear orthogonal polarizations was greater than 20 dB. The unidirectional radiation patterns are stable over the entire operating frequency band, with an average gain of 7.5 dBi. Furthermore, the overall size of the proposed antenna is very compact, amounting to only approximately <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\ 0.36\;{{\mathrm{\lambda }}_{\mathrm{L}}} \times 0.36\; {{\mathrm{\lambda }}_{\mathrm{L}}} \times 0.13\; {{\mathrm{\lambda }}_{\mathrm{L}}}$</tex-math></inline-formula> , where <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${{\mathrm{\lambda }}_{\mathrm{L}}}$</tex-math></inline-formula> is the longest operating wavelength.

Dual-Polarized Antenna With Dual-Differential Integrated Feeding for Wideband Full-Duplex Systems

A new two-port dual-polarized planar antenna with an integrated feeding circuit for in-band full-duplex (FD) (IBFD) applications is presented. The antenna consists of four H-shape slots, stacked patches for enhanced bandwidth (BW), and a separate layer of two differential (0° and 180° split) power dividers connected using vertical transmission lines which define the feeding system. The multilayer antenna is well matched from about 2.2 to 2.5 GHz with isolation values from about 40 to 60 dB. When compared to similar IBFD antenna systems, the proposed configuration provides a higher isolation BW (10%) and higher gain (7.8 dBi) whilst adopting a simple feeding network. Also, by using the proposed feeding circuit, the manufactured antenna does not require any external cables and couplers. This simplifies the structure and reduces the number of cable connections. This allows for other analog-based self-interference reduction schemes for further improvements in the transmit and receive data link. In addition, the proposed antenna design was extended to a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4 \times 1$ </tex-math></inline-formula> array. These dual-differential IBFD antenna systems are a good alternative to more conventional FD designs which typically require external coupler-based feeding. In addition, the operating BWs and isolation values offered by these S-band systems can support new data link possibilities for beam steering and future IBFD wireless networks by low-cost antenna and feeding circuit integration.

A Dual-Polarized Planar Antenna Array Differentially-Fed by Orthomode Transducer

This article presents a new design of a differentially fed substrate integrated planar antenna array with dual-polarization. Compared with the traditional dual-polarized antenna arrays, the proposed array antenna has the advantages of simple configuration, high cross-polarization discrimination (XPD), and high gain. The 2×2-element subarray design with a via-loaded crossover structure is used, which reduces the complexity of the array antenna. The operation bandwidth is improved by generating three resonances in the subarray. An 8×8 antenna array is designed, prototyped, and tested to exemplify its potential applications in large dual-polarized antenna arrays. A planar orthomode transducer is used to achieve differential excitation for the antenna array. The measured results show that the proposed antenna array has an impedance bandwidth of 19.2-20.7 GHz for |S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> | <; -10 dB and port isolation higher than 20 dB. The array antenna exhibits a high XPD of 43 dB and a flat gain of about 22.2 dBi within the bandwidth.

Triband Dual-Polarized Shared-Aperture Antenna for 2G/3G/4G/5G Base Station Applications

This article presents a novel triband dual-polarized shared-aperture antenna with frequency-selective function for sub-6 GHz base station applications. The proposed antenna is composed of a dual-polarized square loop antenna with two parasitic loops for 2G/3G/4G (1710-2690 MHz) and a differentially fed dual-polarized planar antenna for 5G (3300-3600 and 4800-5000 MHz) base station applications. These two antennas are placed coaxially but different altitudes for saving the installation space. In order to achieve good individual performance for these two antennas in the same aperture without interference or blocking, the lower band (LB) antenna is designed as a frequency-selective surface (FSS) for the nether mid/upper bands (M/UBs) antenna. The measured results show that the proposed antenna achieves a high port isolation (>20 dB) between LB and M/UBs and a -10-dB impedance bandwidth of 50.4% (1.60-2.70 GHz), 14.9% (3.28-3.80 GHz), and 8.6% (4.75-5.18 GHz). To further validate the design concept, an antenna array composed of four LB elements and eight M/UBs elements with the corresponding spacing is fabricated and measured, which demonstrates the application of the triband shared-aperture antenna in array form.

Dual-Polarized Planar-Printed Ultrawideband Antenna Array on a Triangular Grid

This article presents a dual-polarized planar-printed ultrawideband antenna array on an optimally sampled triangular (hexagonal) lattice. The design is based on the dual-polarized planar ultrawideband modular antenna (PUMA). In this article, the dual-polarized square lattice PUMA array is adapted to an equilateral triangular lattice for grating-lobe-free scanning at a 15.5% reduced element count. A prototype triangular lattice PUMA array is built and compared with a square lattice PUMA aperture of similar size. As configured, the triangular lattice array demonstrates an 8% larger aperture area with 7% fewer elements than the square lattice array. Modeling predictions are validated with measured results for embedded element performance. The triangular lattice PUMA is shown to compare favorably to the square lattice PUMA with modest performance compromises.

A Crossed Dipole Phased Array Antenna Architecture With Enhanced Polarization and Isolation Characteristics

A dual-polarized planar phased array antenna with enhanced polarization and isolation characteristics for multifunction applications is presented. A bent crossed dipole is selected as the element of the array antenna. The bend angle is optimized to widen the E-plane active element pattern of the dipole resulting in a pair of matched co-polar patterns. Contrary to common patch array antennas, this design does not require a continuous grounded substrate. This diminishes the surface wave propagation along the ground plane. Efficient techniques, applied to the element design, isolate the two polarizations from each other. Higher than 40 dB port isolation is achieved within the entire frequency range of 2.7–3.0 GHz in principal plane scanning. In order to preserve the symmetry of the array antenna, a mirrored arrangement in both orthogonal directions is applied to the array configuration. This enhances the co- to cross-polarization levels to better than 45 dB in scanning up to ±45° in the principal planes. The proposed phased array antenna with enhanced polarization purity can potentially improve polarimetric performance.

Dual-Polarized Planar Phased Array Antenna With Cavity-Backed Elements

A planar dual-polarized phased array antenna with cavity-backed elements is proposed in this letter. The array antenna is designed based on a dual-polarized patch antenna element with vertical orthogonal baluns. The antenna element is backed by a compact cavity to reduce the interelement mutual coupling and enhance the scanning performance of the planar array. The proposed array achieves a wide fractional bandwidth of over 20% when scanning up to ±45° in the E- and H-planes. The isolation between the two orthogonal ports in the same element is higher than 30 dB. The validity of a design is verified by simulation and measurements of a 10 × 10 array prototype.

Wideband Differentially Fed Dual-Polarized Planar Antenna and Its Array With High Common-Mode Suppression

A differentially fed dual-polarized planar antenna with a wide bandwidth and high common-mode (CM) suppression is presented in this paper. The antenna is composed of four folded dipoles that are connected to each other via the coplanar striplines. Two integrated baluns are utilized to excite the folded dipoles simultaneously to realize ±45° linear polarizations. Owing to the loaded shorting stubs, the impedance matching is improved and the operational bandwidth is broadened. Under differential-mode (DM) excitation, the antenna has a superior unidirectional radiation over a wide bandwidth. Under CM excitation, the antenna achieves a high level of CM suppression performance due to the proposed feeding structure. Measured results exhibit that the antenna gains a wide −15 dB differential impedance bandwidth of 51.1% (1.66–2.80 GHz) and a high port isolation of 38 dB between the differential ports. Moreover, the CM reflection coefficient is larger than −1.32 dB within the DM passband, which indicates that the high CM suppression is attained. To further validate the design concept, a $1\times4$ antenna array is fabricated and measured to demonstrate the superior performances of wide bandwidth, high port isolation, high CM rejection, and good unidirectional radiation.

Dual-Band Dual-Polarized Antenna Array With Flat-Top and Sharp Cutoff Radiation Patterns for 2G/3G/LTE Cellular Bands

This paper proposes a dual-band dual-polarized planar antenna array with flat-top and sharp cutoff radiation patterns for 2G/3G/LTE base stations. The array consists of $8 \times 8$ antenna elements arranged with nonuniform spacings and is assigned with optimized nonuniform excitations to achieve flat-top and sharp cutoff radiation patterns with low sidelobes. The radiating element consists of two square-shaped PCB boards. Extra adjustable coupling elements are introduced in the H-shaped patches to improve the impedance matching performance in an array environment as well as to reduce the size of the antenna element. In the 1.71–2.69 GHz band, the dual-polarized radiating element exhibits stable radiation patterns, excellent impedance matching (VSWR 40 dB). Frequency band selective variables are defined to group the antenna elements. They are optimized along with the element spacings and complex excitations in the optimizer to ensure stable flat-top radiation patterns. Rectangular-shaped baffles are introduced to reduce mutual couplings. A prototype of the $8 \times 8$ antenna array has been fabricated and measured. The results indicate that the proposed dual-band dual-polarized planar array achieves a half-power beamwidth of 50° ± 5° in both the H-plane and E-plane. The proposed antenna and its array exhibit attractive potentials for 2G/3G/LTE base station applications.

Low‐Profile Dual‐Polarized Planar Antenna with Compact Structure for Base Stations

A low-profile dual-polarized planar antenna with compact structure for 2.4GHz Wireless local area network (WLAN) and 2.5GHz Long term evaluation (LTE2500) base stations is proposed. A combination of a planar radiator and compact Artificial magnetic conductor (AMC) reflector is utilized to achieve a full planar structure without adding extra matching circuit, an extremely low-profile of 0.127 wavelength, as well as a high front to back ratio (F/B) of 25dB. The antenna is fabricated to test the performance such as S-parameters, radiation patterns and peak gain. Reasonable results show the suitability of the proposed antenna for 2.4GHz WLAN and LTE2500 applications.

A Broadband Differentially Fed Dual-Polarized Planar Antenna

A novel broadband differentially fed dual-polarized planar antenna is proposed in this communication. The antenna is composed of two dual-dipole elements, each of which is differentially fed by two coaxial cables through a short stub. Four pairs of parasitic elements are introduced to enhance the bandwidth. Both the dual-dipole elements and the parasitic elements are etched on the same substrate, making the antenna feature a planar configuration. The antenna achieves a 15-dB differential impedance bandwidth of 45% ( $\vert S_{\mathrm{ dd11}}\vert dB), a high isolation of 45 dB, an antenna gain of ~9 dBi, and a half-power beamwidth of 65° ± 8°.

A Dual-polarized Planar Antenna Using Four Folded Dipoles and Its Array for Base Stations

A ±45° dual-polarized base station antenna with a planar structure is proposed for 2G/3G bands. The +45° antenna and the −45° antenna share the same radiator, which is composed of four folded dipoles and four coplanar striplines. The coplanar striplines work as $\lambda $ /4 impedance transformers. Two Y-shaped feeding lines is designed to obtain a good impedance matching and a planar reflector is employed to achieve a stable radiation pattern. The antenna element has a wide impedance bandwidth of 27.8% with SWR 30 dB), a stable radiation pattern with 3-dB beamwidth 65° ± 5° in the horizontal plane, a high XPD and a high front-to-back ratio were achieved.

Design of Wideband Dual-Polarized Planar Antenna Using Multimode Concept

A wideband dual-polarized planar antenna is designed and analyzed by using the theory of characteristic modes (TCM). The eigenvalue, eigencurrent, characteristic pattern, and modal weighting coefficient are analyzed to bring physical insight to this kind of antenna. The results demonstrate that there are two modes resonant in the operating band for each polarization, which have been combined to form a wider frequency band. A bandwidth of 60.2% (1.72–3.2 GHz) for VSWR &lt; 1.5 with high isolation of 32 dB is achieved simultaneously. The size of the radiator structure is 0.33λ0× 0.33λ0× 0.22λ0(λ0refers to the center operating frequency).

A Broadband Dual-Polarized Planar Antenna for 2G/3G/LTE Base Stations

A broadband dual-polarized planar antenna is proposed for 2G/3G/LTE base stations. The dual-polarized antenna is composed of two perpendicularly crossed bow-tie dipoles. Each bow-tie dipole is excited by a microstrip stub that is directly fed by a coaxial line, making the dual-polarized antenna full planar. Due to the coupling between two crossed bow-tie dipoles, a broad bandwidth is achieved. It is shown that the dual-polarized antenna has a bandwidth of 45% (1.7-2.7 GHz) for return loss >15 dB with an isolation of higher than 30 dB between two polarization input ports. The dual-polarized antenna has a half-power beam width (HPBW) of around 65 ° and an average gain of 8.5 dBi for slant ±45° polarizations. An 8-element dual-polarized planar antenna array is developed for base station applications. A bandwidth of 56% (1.63-2.9 GHz) is obtained for the antenna array. The antenna gain of the array is about 16 dBi and the HPBW is 65±8° for each polarization.

A Novel Broadband Planar Antenna for 2G/3G/LTE Base Stations

A novel broadband planar antenna is developed for mobile communication base stations. The antenna is composed of a pair of folded dipoles which are coupling fed by an L-shaped microstrip line. Both the dipoles and the coupling microstrip line are etched on the same substrate. The planar antenna achieves a bandwidth of 53% for ${\rm return loss} > 15$ dB, covering the frequency range 1.65–2.85 GHz for 2G/3G/LTE applications. The antenna gain of the broadband antenna element is about 9 dBi. A ${\pm}45^{\circ}$ dual-polarized planar antenna consisting of two broadband antenna elements is proposed, which achieves a bandwidth of about 50% and an isolation of 30 dB. Two 8-element antenna arrays are developed respectively for the broadband antenna and for the ${\pm}45^{\circ}$ dual-polarized antenna. Both antenna arrays achieve a bandwidth of more than 58% (1.6–2.9 GHz). The antenna gains achieved for the both antenna arrays are higher than 15.5 dBi. The half-power beam widths in the horizontal plane for the antenna arrays are approximately $65\pm 10^{\circ}$ , suitable for base station applications.

A 7–21 GHz Dual-Polarized Planar Ultrawideband Modular Antenna (PUMA) Array

The design, fabrication, and measurement of a 16 × 16 dual-polarized planar ultrawideband modular antenna (PUMA) array operating over 7-21 GHz (3:1 bandwidth) are presented. The array is comprised of tightly coupled dipoles printed on a grounded dielectric substrate and are excited by an unbalanced feeding scheme that eliminates external wideband baluns and feed organizers. The array can be assembled modularly, where each low-profile, fully planar, low-cost tile is fabricated using standard multilayer microwave PCB techniques. A unique solderless, modular interconnect mates the array to a dilation fixture that facilitates measurements using standard surface-mount assembly (SMA) connectors and terminations. After presenting the most critical design trends, simulation results of the final array in infinite, infinite × finite, and finite × finite models are compared with measurements. This prototype array exhibits a measured active VSWR <; 2.1 and close to ideal gain at broadside, and VSWR <; 2.8 with low cross-polarization out to θ = 45° in all planes, showing close agreement with simulations.

Dual-Polarized Planar Feed for Low-Profile Hemispherical Luneburg Lens Antennas

A dual-polarized planar feed antenna suitable for illuminating a hemispherical Luneburg lens on a ground plane operating at Ku band is presented. Compared to a waveguide feed, the planar antenna has the advantage of reducing the overall profile of the lens system. The planar feed is realized using a 2 × 2 array of stacked patches, and orthogonal polarizations of the patches use different coupling methods to increase isolation between the two ports of the device. Simulated S-parameters, radiation patterns, gain, directivity, and efficiency of the planar feed are compared with measured results. Measured radiation patterns and gain are also presented for a commercial Luneburg lens illuminated by the planar feed, to characterize the combined lens/feed performance and to validate the utility of the planar feed design.