Polarized Antenna Array Research Articles

Wideband circularly polarised antenna array with isoflux pattern

The authors present a wideband circularly polarised antenna array consisting of a 10-element ellipse dipole antenna and a feed network. A metal pillar is vertically loaded at the end of each ellipse dipole arm to extend the current path, thereby reducing the lateral dimension of the antenna element. For uniform coverage over the Earth's surface, antenna with an isoflux pattern is required due to its uniform power density over a wide coverage area. To obtain wideband and isoflux characteristics, the amplitude and phase distributions along the network are optimised by applying the hybrid of the genetic algorithm and particle swarm optimisation. Particularly, the feed network with broadband phase shifting performance is designed to attain a broad bandwidth requirement. The proposed antenna can achieve excellent impedance matching and axial ratio characteristics from 1.1 to 1.6 GHz. In addition, the isoflux radiation pattern is obtained with the beamwidth of ±21° where the gain is higher than 0 dBi in the elevation plane (xoz-Plane). The realised gain is better than 10.2 dBi and the side lobes are below −14.2dB across the operating frequency. Finally, the antenna array is manufactured and measured, and good agreement is achieved between the simulation and measurement results.

A right‐handed circularly polarized array antenna based on gap waveguide technology at 35 GHz

AbstractIn this article, the authors have proposed a right‐handed circularly‐polarized array antenna with gap waveguide (GWG) distribution network at 35 GHz. By using GWG technology, the strict electrical contact of different layers is not required so that the expensive vacuum welding or the diffusion bonding technology can be avoided. The entire geometry consists of the top radiation layer and two distribution network layers on the bottom. The aperture shape of the top radiation layer has been designed as a hexagon in order to generate the circular‐polarized electromagnetic waves. The final measurement results show that the reflection coefficient of the whole array antenna is below −10 dB with 8.45% bandwidth where the axial ratio is less than 2 dB. The antenna efficiency is higher than 70% over the whole operating frequency band, and the corresponding antenna gain is higher than 30.8 dBi.

Wideband, low radar cross section circularly polarized array antenna based on metasurface and sequential phase feed

A planar circularly polarized (CP) array antenna based on polarization conversion electromagnetic band-gap (PCEBG) and sequential phase (SP) feed network with wideband circular polarization and low radar cross section (RCS) is presented. The array is formed by 2 × 2 PCEBG elements. The CP performance is obtained due to the PCEBG, and the SP feed network contributes to the wide bandwidth and symmetric radiation pattern. The proposed array antenna, with an overall size of 64 mm × 64 mm × 2.008 mm (1.6 λ0 × 1.6 λ0 × 0.05 λ0 at 7.5 GHz) has been fabricated and measured. The measured results are as follows, an impedance bandwidth of 42.90% (6.61-10.22 GHz), a 3-dB axial ratio bandwidth (ARBW) of 28.3% (6.65-8.83 GHz) and a 3-dB gain bandwidth of 23.7% (6.7-8.5 GHz). The antenna exhibits left-hand CP(LHCP) characteristics with a peak broadside gain of 14.1 dB. The proposed antenna achieves an in-band and out-band RCS reduction more than 8 dB under normal incidence. The measured results are in agreement with the simulated results.

60‐ghz wideband circularly polarized antenna array based on TE 340 ‐mode SIC and sequential rotation feeding technique

60‐ghz wideband circularly polarized antenna array based on <i>TE</i> ₃₄₀ ‐mode SIC and sequential rotation feeding technique

Basic Study of a Monopulse DOA Estimation Circularly Polarized Array Antenna Integrated with Magic-Ts

Basic Study of a Monopulse DOA Estimation Circularly Polarized Array Antenna Integrated with Magic-Ts

Circular Polarization Array Antenna with Triplate Stripline Elliptic Resonator Antennas

This paper presents a plane antenna and array for X-band circular polarization. The novel factors of this development are elliptic resonator antenna and Glass-Epoxy substrates. High efficiency in resonance and radiation of microwave energy is expected by elliptic resonators. Easy process in fabrication is expected by Glass-Epoxy substrate. Elliptic ratios of feed- and reactance-elements are chosen independently each other. The dielectric constant εr and tan δ are 4.6 and 0.010 respectively. Enough bandwidth of axial ratio of circular polarization and directive gain are confirmed to be 15 % of central frequency and 10 dB respectively for antenna array.

High gain, low radar cross‐section, and left hand circularly polarized antenna array based on metamaterial inspired elements

AbstractIn this research work, a wideband metamaterial‐inspired circularly polarized antenna array is designed. The designed antenna array has a low radar cross‐section (RCS) but high gain. The basic element of the planar array is analyzed as a dual‐band electromagnetic absorber. Under normal incidence, the designed basic element has two absorbing peaks at 3.6 and 11.2 GHz. Further, four elements of the 4 × 4 elements array are connected to the feeding network through metallic vias. The feeding network is designed on the bottom layer. The circular polarization is archived by feeding the cross shape metallic resonator at two feed points, in a manner that there is a 90° time phase difference between the fields of two. It is shown that a good axial ratio is obtained over a wideband. This design method simultaneously validates high gain antenna performance and also meets the conditions of low‐RCS.

Dual-Band Dual-Circularly Polarized Antenna Array With Printed Ridge Gap Waveguide

A dual-band dual-circularly polarized magneto-electric dipole antenna array for full-duplex communication systems is presented in this communication. The proposed array can simultaneously achieve left-hand circular polarization (LHCP) around 20 GHz and right-hand circular polarization (RHCP) around 30 GHz with a low-loss feed network using the printed ridge gap waveguide (PRGW). The antenna is composed of two sets of stacked interconnected short-circuit patches operating at different frequencies and fed by the same gap. The LHCP at the 20 GHz band and RHCP at the 30 GHz band are realized by exciting the corresponding orthogonal electric-dipole mode and magnetic-dipole mode with -90°/90° phase difference. A cylindrical cavity consists of a series of metalized vias with a top metal strip used for surface wave inhibition. Using the PRGW, a four-way power divider with a low transmission loss is designed. Finally, the simulated 2 ×2 array was fabricated and measured. The measurement results show that the impedance bandwidths are 18.85-20.8 and 29.5-30.9 GHz. The 3 dB axial ratio bandwidths are 19.4-20.4 and 28.5-31.4 GHz, with the peak gains of 13.2 and 11.5 dBic, respectively.

Dual polarized antenna array of planar dipoles for mobile communication base stations of 3,3–5,9 GHz band

Dual polarized antenna array of planar dipoles for mobile communication base stations of 3,3–5,9 GHz band

Fast Measurement of Single-Cut Far-Field Patterns at Quasi-Far-Field Distance for Linear Antenna Array of Any Polarization

Corrected method for fast measurement of single-cut Far-Field (FF) pattern at Quasi-Far-Field (QFF) distance for linear antenna array of any polarization by two orthogonal measurements has been proposed in this paper. The analytical equations were deduced based on cylindrical wave expansion (CWE). The required measurement distance of proposed method don’t need to satisfy the FF condition of the antenna under test (AUT), only need to satisfy the FF region of small dimension of the AUT, so it is in the Quasi-Far-Field (QFF) of another large dimension, which makes the process same as FF measurements. Therefore, the introduced method is especially applicable to arbitrary polarized antennas with one dimension large, and another dimension small. 45° linearly polarized and circularly polarized antenna array were simulated to prove the proposed method, the corrected results using the presented algorithm are consistent with the theoretical results.

A single fed wideband mode‐reconfigurable OAM metasurface CP antenna array with simple feeding scheme

In this paper, a low-profile mode reconfigurable orbital angular momentum (OAM) circular polarization (CP) array antenna is presented, which consists of 2 × 2 elements and a single feed network. Each element is a metasurface subarray composed of 4 × 4 square patchs. The vias in the subarray produces 90° phase difference between x- and y- polarizations, and CP is realized. Both the 90° phase-shifting reconfigurable feed network and broadband 180° phase shift by the mirror images are used to generate the OAM helical phase. The OAM modes l can be dynamically switched between l = +1 and l = −1 by controlling operation states of p-i-n diodes in the feed network. The CP and OAM impedance bandwidths are 13.3% (from 5.8 to 6.6 GHz). The peak gains for the two modes are 9.4 dBi. The developed array antenna has the following advantages of the least pin diode number, high gain, small size, lowest divergence angle, wideband CP, low cross-polarization and low fabrication cost. Therefore, the proposed antenna is very promising for modern high-speed and large capacity wireless communication systems.

Dual Circularly Polarized Array Antenna Based on Corporate Feeding Network in Square Waveguide Technology

In this communication, the design and fabrication of a Ku -band antenna array is presented for dual circular polarization, using a corporate feeding network (CFN) with orthogonal dual-mode operation. A four-way CFN in square waveguide technology is implemented to uniformly illuminate the antenna array. Each of the two propagating modes in the square waveguide excites orthogonal polarizations in the antenna. A dual circularly polarized radiating element is used for the dual-polarized array. Consequently, the link capacity can be doubled by using orthogonal polarizations in a compact and low-loss antenna system. Prototypes have been fabricated by conventional machining and they have been experimentally tested. A 90% total efficiency and matching coefficient better than −10 dB have been obtained in the frequency band between 16.5 and 17.5 GHz for the dual circularly polarized antenna. Further simulations have proven the validity of this topology for larger dual-polarized planar arrays.

A High Accuracy Positioning Method for Single Base Station in Indoor Emergency Environment

Objectives In recent years, the demand of indoor and outdoor emergency location service is growing rapidly. Affected by indoor space environment, signal types, sensor performance and other factors, the existing positioning methods of single signal source, single sensor source, integrated navigation, fusion positioning are not perfect in accuracy, stability, reliability, rapidity and other aspects. The main objective of this study is to propose a high precision wireless location method for single base station in emergency positioning environment. Methods A method of angle measurement with high precision was proposed to eliminate redundant phase caused by modulated signal and sequential sampling. Firstly, a circular antenna array was constructed which sampling received signal on one channel by switching the dual polarized antenna array element in turn, and on the second channel by comparison antenna. Then, the echo signal mathematical model of dual channel antenna was established. Finally, the super-resolution angle estimation algorithm of Capon spectral and polarization decoupling was given for multipath indoor environment. In order to reduce the computational complexity of four-dimensional search, the steering vector was rewritten by hardard product, and target angle estimation was obtained by solving the minimum eigenvalue to minimize the cost function. Results From the comparison results of array phases between single channel and dual channel, it can be seen that the proposed two channel antenna has better phase stability. Experimental results on several fixed location points demonstrate that the root mean square(RMS) positioning error in X direction and Z direction is better than 0.5 m. Both static and dynamic tests show that the influence of source signal phase and frequency synchronization error to switch-antenna array can be effectively eliminated. Conclusions The proposed method can achieve two-dimensional accurate localization with a single base station, which has wider application than the single channel switch-antenna array and is easy to rapid deployment in emergency positioning environment.

High-Directivity, Compact, Omnidirectional Horizontally Polarized Antenna Array

Omnidirectional horizontally polarized (OTIP) X-band magnetic dipole (MD) antenna arrays are reported that simultaneously achieve high directivity and wide bandwidth while being compact in size. A major innovation is the seamless integration of several phase inverters into an electrically long TE0.5,0 mode open waveguide. The resulting open structure radiates as a collinear series of MD sections. The inverters facilitate the realization of in-phase electric fields along its entire length and, hence, phase coherence between all of these MDs. Each phase inverter is realized as a combination of a meandering slot on one metallic surface of the waveguide and several shorting vias surrounding it. Two such multistaged (six- and eight-element) collinear OTIP MD arrays were designed and optimized. Prototypes of both were fabricated with standard, low-cost PCB manufacturing technology. The volume of the six-element (eight-element) OTIP array is only 0.07 × 0.22 × 3.3 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> (0.07 × 0.22 × 4.3 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> ); it achieves a measured 8.2 dBi (10.4 dBi) peak realized gain (RG). The measured overlapping -10 dB impedance bandwidth and 3 dB RG bandwidth was 8% in both cases. These designs are ideal for wireless applications requiring thin high-directivity TIP sources covering the entire azimuthal plane.

Wideband Circularly Polarized Array Antennas With Sequential-Rotation Polarization Grid and Simplified Full-SIW Feeding Networks

Two wideband circularly polarized (CP) antenna arrays are proposed, based on sequential rotation (SQR) arranged polarization grid and specially designed wideband full-substrate integrated waveguide (SIW) SQR feeding network. First, as the CP array element, an SIW-excited log-periodic dipole array (LPDA) loaded with an inhomogeneous polarization grid is designed. Then, the element with the grid is extended into a 2×2-element SQR array, and a wideband planar SIW-feeding cavity is used to provide the full-SIW array feeding. The SQR configuration is simplified by exploring the symmetric property of the LPDA dipole elements for 180° phase shift. Finally, in order to solve the high sidelobe problem existing in the first array design, another full-SIW array configuration with a new 3-D SIW-feeding cavity for the purpose of element spacing reduction is proposed. Another SQR network simplification method is studied here in favor of the 3-D SIW-feeding cavity, in which the out-of-phase power division property of the SIW E-plane junction is explored. With this configuration, a much lower sidelobe result is obtained by the second array. The measured results indicate that both arrays have advantages of wide CP working bandwidth (37%), high efficiencies (~80%), and also wide 3 dB gain bandwidth (39%).

A wideband circularly polarized antenna array with sequential rotation feed

A novel wideband circularly polarized (CP) antenna array is designed, which consists of a horizontally placed wideband phase shifting feed network and four vertically placed linearly polarized dipole antenna elements, and the circular polarization is realized based on sequential rotation feeding technology. By placing two parasitic strips and two grounding strips on the top and side of each T-shaped dipole antenna element, the impedance bandwidth and circular polarization performance of the antenna can be further improved. The simulation results show that the 10-dB impedance bandwidth of the antenna is 93% (1.56-4.27 GHz) and the 3-dB AR bandwidth is 80.7% (1.7-4.0 GHz). The measured results are in good agreement with the simulation results. Due to the use of orthogonally placed wideband feed network and wideband array elements, the proposed antenna array has a wider circular polarization bandwidth than the similar antenna arrays reported.

Two-Dimensional Beampattern Synthesis for Polarized Smart Antenna Array and Its Sparse Array Optimization

Polarized smart antenna array has attracted considerable interest due to its capacity of matched reception or interference suppression for active sensing systems. Existing literature does not take full advantage of the combination of polarization isolation and smart antennas and only focuses on uniform linear array (ULA). In this paper, an innovative synthesis two-dimensional beampattern method with a null that has cross-polarization for polarized planar arrays is proposed in the first stage. This method aims to further enhance the capability of interference suppression whose optimization problem can be solved by second-order conic programming. In the second stage, a new sparse array-optimized method for the polarized antenna array is proposed to reduce the high cost caused by the planar array that is composed of polarized dipole antennas. Numerical examples are provided to demonstrate the advantages of the proposed approach over state-of-the-art methods.

Single-Layer Wideband End-Fire Dual-Polarized Antenna Array for Device-to-Device Communication in 5G Wireless Systems

A millimeter wave (mm-wave) wideband dual-linearly polarized antenna array with the end-fire radiation is presented as a promising candidate for device-to-device (D2D) communications in the 5G wireless systems. To realize the property of dual polarizations, two types of orthogonally-polarized radiators are arranged alternately, forming a linear array. By using the crossover, the whole array architecture, including radiators and feed networks, is built into a same layer. A 2 × 4-element array prototype is architected based on the substrate integrated waveguide (SIW) technology. Both radiators and feed networks are carefully designed and analyzed for a wideband operation. Experimentally, the proposed array obtains an impedance bandwidth of 28.6% (24∼32 GHz) for both polarizations. The port isolation is larger than 18.85 dB. Peak gains are 10.5 dBi and 11.6 dBi for the horizontal and vertical polarizations, respectively.

Single-layer wideband circularly polarized antenna array using sequential phase feed for C-band applications

This paper proposes a circularly polarized 2 × 2 antenna array for C-band wireless applications. The most attractive feature of the proposed design is that it is only fabricated on a single layer of a dielectric substrate, while maintaining wideband operation and high gain radiation as well. The single-layer design is able to significant reduce the antenna’s complexity. The array element is based on a truncated corner patch and a periodic structure. The final prototype of 2 × 2 antenna array with overall dimensions of 1.2λ × 1.2λ × 0.04λ, where λ is the lowest operating frequency, was fabricated and experimentally validated. The proposed array yields a measured impedance bandwidth of 42.9% (4.4–6.8 GHz) and a measured 3-dB axial ratio bandwidth of 36.4% (4.5–6.5 GHz). Within the operating band, good radiation patterns are achieved and the boresight gain is from 9.5 to 11.5 dBic. Compared with the other reported single-layer sequential-fed antenna arrays in literature, the proposed shows the best operating bandwidth with competitive gain radiation.

Characterization of Metasurface Lens Antenna for Sub-6 GHz Dual-Polarization Full-Dimension Massive MIMO and Multibeam Systems

A metasurface lens antenna fed by a planar $8\times8$ dual polarized antenna array is proposed and characterized for full-dimensional massive multiple-input multiple-output (MIMO) and multibeam systems at sub-6 GHz bands. The lightweight multilayer metasurface structure consisting of Jerusalem cross elements is used for a planar lens design. The lens antenna with the size of $10\lambda _{0} \times 10\lambda _{0} \times 5\lambda _{0}$ is fed by an $8\times8$ dual-polarized stacked patch array to operate over the range from 5.17 to 6.10 GHz, where $\lambda _{0}$ is the free-space operating wavelength at the center frequency of 5.6 GHz. This article shows the scanning range of ±25° with a maximum gain of 22.4 dBi and the gain variation of 3.3 dB at 5.6 GHz. Beam coverage performance, pattern envelope correlation coefficient, and port isolation properties demonstrate its full-dimension access capability of the antenna. Besides, the multibeam antenna system with high-gain coverage is achieved by beams operating at the same frequencies, while the frequency division multiplexing can be realized for the isolated beams. The proposed metasurface lens antenna, featuring lightweight, compactness, and low cost compared to a 3-D dielectric lens and low-complexity compared to the array scenarios, can be an alternative for fifth-generation (5G) sub-6 GHz frequency bands.