Wide-angle Scanning Phased Array Research Articles

Ka-Band Wide-Angle Scanning Phased Array with Dual Circular Polarization

A wide-angle scanning phased array with dual circular polarization in the Ka-band is presented in this paper. To improve the scanning capability of the phased array, the microstrip element is modified by loading many metal posts at its center and periphery. In addition, a stripline coupler is designed to achieve dual circularly polarized (CP) radiation, and the inner conductor of the subminiature micro-push-on (SSMP) connectors for feeding the coupler is extended to the top layer of the multilayer element by introducing an open stub, which simplifies the assembly process between the SSMP connector and multilayer printed circuit board (PCB) due to through-hole soldering instead of blind-hole soldering. The proposed element can cover a frequency range from 28 GHz to 30.5 GHz with a relative bandwidth of 8.5% in the Ka-band. An 8 × 8 phased array is constructed based on this proposed element, and a wide-angle scanning range from −65° to +65° is obtained for the dual circular polarization. The proposed array has a gain fluctuation of 5.1 dB and an axial ratio (AR) of less than 3.3 dB during beam-steering. The prototype is fabricated and measured, with a good agreement between the measured and simulated results. The proposed phased array can be applied in a Ka-band millimeter-wave (MMW) communication system.

Design of Compact, Broadband, 2-D Wide-Angle Scanning and Low-RCS Phased Array Using Split Ring Structures

Design of Compact, Broadband, 2-D Wide-Angle Scanning and Low-RCS Phased Array Using Split Ring Structures

Circularly Polarized Wide-Angle Scanning Phased Array Based on Heterogeneous Beam Elements

Circularly Polarized Wide-Angle Scanning Phased Array Based on Heterogeneous Beam Elements

Wide-angle scanning and Wideband millimeter-wave phased array with Enhanced Isolation using Novel Triple-function Electric Walls

A wide-angle scanning millimeter-wave (mm-wave) phased array with enhanced bandwidth and isolation using novel triple-function electric walls (TEWs) is presented in this work. First, a novel concept for element beamwidth broadening is proposed by using a suspended horizontal magnetic current (SHMC) with a conical pattern. Then, based on this concept, an antenna element is designed using the proposed TEWs. TEWs not only broaden the element beamwidth by forming a suspended horizontal magnetic current(SHMC), but also widen the element bandwidth by introducing a new mode. Meanwhile, the proposed TEWs can be used as a band-stop filter in the array to reduce the mutual coupling. Based on the three beneficial functions of the proposed TEWs, a wide-angle scanning mm wave phased array with enhanced bandwidth and isolation is designed. Measured results show that the phased array achieves an active impedance bandwidth of 19.3% (24.7-30 GHz) and a good isolation of more than 15 dB. Meanwhile, a wide 3 dB scanning angle larger than ±74° is achieved by the proposed array with the maximum scanning angle of ±80° at 27 GHz.

1-D Wide-Angle Scanning Phased Array With Enhanced Gain and Reduced Mutual Coupling Using Thin Dielectric Superstrate

1-D Wide-Angle Scanning Phased Array With Enhanced Gain and Reduced Mutual Coupling Using Thin Dielectric Superstrate

Dual-CP Antenna with Wide-HPBW and Wide-ARBW Performance for Wide-Angle Scanning Phased Array

Dual-CP Antenna with Wide-HPBW and Wide-ARBW Performance for Wide-Angle Scanning Phased Array

Millimeter-Wave Wide-Angle Scanning Phased Array Antenna Based on Heterogeneous Beam Elements

By imitating the element inclined beam distribution of a curved surface conformal (CSC) phased array antenna (PAA), a pseudo-curved surface conformal (PCSC) PAA realizes wide-angle scanning while maintaining a planar low profile. Inspired by the PCSC PAA, this communication proposes a PAA based on heterogeneous beam elements (HBEs) to realize wide-angle scanning. Using HBEs introduces a new design degree of freedom (DoFs), namely the element beam shape, to PAA. By optimizing HBEs and their arrangement, the effective aperture of a PAA can be increased at large scanning angles, and thus the scanning range can be improved. To verify the idea, first, a wide-beam 1×4-element subarray is developed. Then, a standard 4×4-element PAA is implemented using four uniform 1×4-element subarrays, achieving a >±60° 3-dB gain variation scanning range. At last, based on the standard PAA, by adjusting its structure to tailor four subarrays’ beam inclinations, a 4×4-element HBE PAA is designed. It further improves the scanning range to >±70° at an average cost of ~1.5dBi broadside scanning gain within the 5G mmWave band (24.25-29.5GHz, 19.5%). To the authors’ best knowledge, compared with the former planar mmWave PAAs, the proposed design shows the widest scanning range in a wide bandwidth.

Design and analysis of a metasurface-based wideband wide-angle scanning phased array

This paper presents a wideband wide-angle scanning phased array, which employs Φ-shaped unit cells to form a metasurface (MS) for achieving wideband impedance matching. To optimize the impedance matching performance, a design procedure based on an equivalent circuit model is proposed. A quasi-analytical model based on the equivalent circuit model and the permittivity ϵ r and permeability μ r of the MS properly predicts the scan range of the full structure, and allows for an accelerated design process. The extensive analysis confirms the effectiveness of the MS as the wideband angle impedance matching layer for the antenna array. The MS has demonstrated a positive impact on the wideband wide-angle scanning performance. Finally, a prototype is fabricated and measured, and the experimental results agree well with the simulation results. The proposed array exhibits wide-angle scanning across a 3.5:1 impedance bandwidth (2–7 GHz) with ±60° scan volume in both E-plane and H-plane.

Circularly Polarized Metasurface Phased Array Antenna System With Wide Axial-Ratio Beamwidth for LEO Mobile Satellite Communication

In this paper a millimeter waves LHCP 1×32 with dummy on both sides phased array antenna is proposed. Multi-layer structure and single feed are employed. The antenna patch adopts 3×3 metasurface. The measured impedance bandwidth is 20%, ranging from 22.5 to 27.5 GHz. The axial ratio bandwidth with an axial-ratio (AR) level < 3 dB achieves 3.35 GHz ranging from 24.15 GHz to 27.5 GHz. Relative 3 dB axial ratio bandwidth reaches 13.4%. A total of 37 beams were measured in the anechoic chamber. The results show that whether the phased array antenna system serves as transmitter or receiver, the 3dB beam angle coverage at 26 GHz reaches -42°-45° at φ= 0° and -42°-42° at φ= 90°. The 3 dB axial ratio beam angle ranges from -80° to 89° at φ= 0°, and from -45° to 45° at φ= 90°. Based on this linear array, it is easy to expand to circular polarization planar wide-angle scanning phased array. The antenna system realizes circular polarization with wide angle wide axial ratio beam scanning, which can be used in LEO satellite communication system.

Miniaturized Wide Scanning Angle Phased Array Using EBG Structure for 5G Applications

This article presents a miniaturized wide-angle scanning phased array for fifth-generation (5G) application. A subarray of two closely packed patch antennas on electromagnetic bandgap structure (EBG) ground with the operating bandwidth of 26–29 GHz is used as the basic module of the linear array, which contains four equally spaced subarrays. The existence of the EBG ground enables the array to be compact in size (3.2 × 0.6 × 0.12λL3), yet the mutual coupling between each element can reach to more than 22 dB within the whole band of interest. The EBG structures also contribute to the wide element radiation pattern of the aperiodic array and consequently the wide scanning angle performance of the array. The range of the main beam scan with EBG structure can reach from −70° to 70° with more than 6 dB side lobe levels (SLLs) at 26.5 GHz with 3 dBi scanning gain loss. This proposed method enabling the array to be compact and wide in scanning angle is very attractive for 5G mobile terminal applications.

Dual-Polarized Wide-Angle Scanning Phased Array Antenna for 5G Communication Systems

A dual-polarized phased array antenna is presented with wide-angle scanning capability in this article. To improve the mutual coupling in the array, a current cancellation method (CCM) is proposed by changing the current distribution on the excited unit to induce a pair of the canceled currents on the adjacent unit. Meanwhile, this current distribution broadens the beamwidth of the unit in the array. Besides, the proposed method can also optimize the array unit size and achieve a small inter-unit distance for wide-angle scanning capability. A low-profile dual-polarization antenna operating in the bandwidth from 4.4 to 5.0 GHz is designed as a linear array and a planar array to verify the proposed method. Regardless of the linear array or planar array, the mutual coupling in the array is below −19 dB, which is better than that in conventional arrays. Meanwhile, the antenna unit in the array can radiate a wide-beam pattern. Two arrays can scan over ±60° for both polarizations. Within the scanning range, the realized gain reduction is less than 3 dB and the sidelobe level is lower than −7.5 dB. To verify the performance, two array antenna prototypes are fabricated and tested. The experimental results agree well with the simulation.

A Shaped-Beam Antenna for Wide-Angle Scanning Phased Array

A phased array usually suffers from severe gain drop when its beam steers in a wide range. In this article, an alleviating technique based on a gain-compensating approach is proposed. Isolated element pattern (IEP) and array factor are jointly considered. When calculating the array factor, mutual couplings between antennas in an array are also included. The IEP is optimized in such a way that the element gain is nearly inversely proportional to the peak gain of the array factor. As a result, the peak gain of the overall array beam can be kept almost the same in a wide scanning range. As an example, a cylindrical dielectric resonator antenna (DRA) array is investigated. In such a design, a dip is introduced to the top of the element pattern so that the top peak in the array factor envelope can be compensated. This idea is demonstrated by using an X-band cylindrical DRA, with its beam shaped by using a loading peripheral metal ring and two top dielectric slabs. This shaped-beam DRA element is used to construct a nine-element H-plane linear phased array. The element and array prototypes were fabricated and measured, and reasonable agreement between the measured and simulated results is observed. The measured 3-dB beamwidths of the DRA element are 172° and 149° in the E- and H-planes, respectively. It is found that the H-plane main beam of the DRA array can scan from <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$- \mathrm{72}^{\circ }$ </tex-math></inline-formula> to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$+ \mathrm{72}^{\circ }$ </tex-math></inline-formula> with a small gain fluctuation of less than 0.9 dB.

Wideband Open-Ended Ridge Gap Waveguide Antenna Elements for 1-D and 2-D Wide-Angle Scanning Phased Arrays at 100 GHz

A new antenna element type based on the open-ended ridge gap waveguide (RGW) is proposed for phased array applications. This element type is of a particular interest at high millimeter-wave frequencies ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\geq$</tex-math></inline-formula> 100 GHz) owing to a contactless design alleviating active beam-steering electronic integration. The key challenge addressed here is a realization of a wide fractional bandwidth and a wide scan range with high radiation efficiency. We demonstrate a relatively simple wideband impedance matching network comprised of an aperture stepped ridge segment and a single-pin RGW section. Furthermore, the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$E$</tex-math></inline-formula> - and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$H$</tex-math></inline-formula> -plane grooves are added that effectively suppress antenna elements’ mutual coupling. Results demonstrate a wide-angle beam steering ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\geq \text{50}^\circ$</tex-math></inline-formula> ) over <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\geq {20\%}$</tex-math></inline-formula> fractional bandwidth at the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$W$</tex-math></inline-formula> -band with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\geq {89\%}$</tex-math></inline-formula> radiation efficiency that significantly outperforms the existing solutions at these frequencies. An experimental prototype of a 1 × 19 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$W$</tex-math></inline-formula> -band array validates the proposed design concept through the embedded element pattern measurements.

Wide‐angle scanning phased array using wide‐beamwidth dielectric resonator antenna with miniaturised radiator

A wide-beamwidth dielectric resonator antenna with small radiator is used to design a wide-angle scanning phased array. The proposed dielectric resonator antenna element uses concave structure for wide-beamwidth, and the metal patches on the top of the dielectric resonator are used to reduce the size of radiator. The simulated half-power beamwidth of dielectric resonator antenna is 157.8° and 140.9° in the E- and H-planes, respectively, while the size of the radiator of the dielectric resonator antenna is only 9.7 × 9.7 × 10 mm3 (0.162λ0 × 0.162λ0 × 0.167λ0). One 1 × 8 linear phased array is designed based on the dielectric resonator antenna element. Due to the small size of dielectric resonator radiator, the mutual coupling between the array elements is very small and each element in the array has the similar radiation pattern with wide-beamwidth. Because of these critical features, the phased array can scan from −67° to +67° with a gain fluctuation less than 1 dB and a maximum side lobe level less than −10 dB. Measurement results agree well with simulation.

A planar end‐loaded dipole phased array with enhanced bandwidth and wide‐angle scan

A bandwidth-enhanced wide-angle scanning phased array based on planar end-loaded dipole elements is designed and analyzed in this article. Initially, the phased array is designed based on wideband wide-beam dipole elements, which are placed in a hybrid artificial structure composed of surface waveguide (SWG) and high-impedance surface (HIS). An additional resonance caused by surface-wave propagation in the SWG is generated close to the dipole resonance. The dual-resonance mechanism improves the impedance bandwidth. Then, in order to enhance the array active reflection performance, the HIS is adopted to reduce the coupling between array elements which is caused by the excited surface waves. Besides, the SWG-HIS hybrid structure has a zero-phased reflection in the phased array operation band, which contributes to the wide-angle scan. The total dimension of the proposed eight-element phased array is about 3.24 λ0 × 0.675 λ0 (λ0 is the free-space wavelength at 4.5 GHz). The phased array shows a main-beam scan up to ±60° with a realized gain higher than 8.8 dBi and a total efficiency higher than 84% in an active reflection band of 4.35 ~ 4.85 GHz.

A planar end‐loaded dipole phased array with enhanced bandwidth and wide‐angle scan

A bandwidth-enhanced wide-angle scanning phased array based on planar end-loaded dipole elements is designed and analyzed in this paper. Initially, the phased array is designed based on wideband wide-beam dipole elements, which are placed in a hybrid artificial structure composed of surface waveguide (SWG) and high-impedance surface (HIS). An additional resonance caused by surface-wave propagation in the SWG is generated close to the dipole resonance. The dual-resonance mechanism improves the impedance bandwidth. Then, in order to enhance the array active reflection performance, the HIS is adopted to reduce the coupling between array elements which is caused by the excited surface waves. Besides, the SWG-HIS hybrid structure has a zero-phased reflection in the phased array operation band, which contributes to the wide-angle scan. The total dimension of the proposed eight-element phased array is about 3.24 λ0 × 0.675 λ0 (λ0 is the free-space wavelength at 4.5 GHz). The phased array shows a main-beam scan up to ±60° with a realized gain higher than 8.8 dBi and a total efficiency higher than 84% in an active reflection band of 4.35 ~ 4.85 GHz.

Dual-Port Phase Antenna and Its Application in 1-D Arrays to 2-D Scanning

A novel dual-port phase antenna is proposed to realize 2-D scanning. The antenna consists of two monopoles on both sides and a fishbone structure in the middle. By changing the phase difference <inline-formula> <tex-math notation="LaTeX">${\Delta \varphi }$ </tex-math></inline-formula> between two monopoles, energy is coupled to the proposed structure, exciting different degrees of superposition of even and odd modes. The continuous switching from the broadside lobe to the end-fire lobe is realized, and it has the characteristic of 2-D scanning. Furthermore, to provide an in-depth insight into the 2-D scanning mechanism, two linear arrays (Array 2 and Array 3) based on the proposed antenna element and a generalized principle of pattern multiplication (GPPM) are developed. The fabricated Array 2 can offer scanning angles of 0&#x00B0;&#x2013;73&#x00B0; along the <inline-formula> <tex-math notation="LaTeX">$\theta $ </tex-math></inline-formula>-direction with the gain of 6.5&#x2013;10.4 dBi and 90&#x00B0;&#x2013;140&#x00B0; along the <inline-formula> <tex-math notation="LaTeX">$\Phi $ </tex-math></inline-formula>-direction with the gain of 6.1&#x2013;11.7 dBi. Its scanning coverage of 3 dB beamwidth is <inline-formula> <tex-math notation="LaTeX">$0^{\circ } &lt; \Phi &lt; 140^{\circ }$ </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">$0^{\circ } &lt; \theta &lt; 90^{\circ }$ </tex-math></inline-formula>. The manufactured Array 3 can scan 0&#x00B0;&#x2013;90&#x00B0; along <inline-formula> <tex-math notation="LaTeX">$\theta $ </tex-math></inline-formula>-direction with the gain of 8.2&#x2013;11.1 dBi and 50&#x00B0;&#x2013;90&#x00B0; along the <inline-formula> <tex-math notation="LaTeX">$\Phi $ </tex-math></inline-formula>-direction with the gain of 6&#x2013;9.36 dBi, and its 3 dB coverage of the main beam scanning is <inline-formula> <tex-math notation="LaTeX">$0^{\circ } &lt; \Phi &lt; 180^{\circ }$ </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">$0^{\circ } &lt; \theta &lt; 90^{\circ }$ </tex-math></inline-formula>. Consequently, the proposed antenna and GPPM can be readily extended to wide-angle scanning phased arrays.

Design of an ultra-wideband dual-polarized array antenna

In order to meet the requirements of ultra-wideband wireless communication system applications, this paper studies an ultra-wideband dual-polarization strongly-coupled array antenna. The array element is composed of two pairs of connected printed dipoles orthogonally. The feed network is constructed by the Marchand Balun and the Wilkinson power splitter and realizes the balanced feed, the impedance transformation and common mode resonance suppression. Simulated and measured results show that the proposed antenna achieves an impedance bandwidth of 1.5 GHz to 4.0 GHz, and an E-plane beam scanning range ±60°, H-plane beam scanning range ±50°, and the antenna structure is simple, and is suitable for the applications of dual-polarization wide-angle scanning phased array antenna system.

Design of Physically Connected Wideband SIW Cavity-Backed Patch Antenna for Wide-Angle Scanning Phased Arrays

A novel wideband substrate integrated waveguide (SIW) cavity-backed antenna element and its array are proposed in this letter. The proposed linearly polarized array element consists of a SIW cavity, stacked patches, and a coaxial probe. The SIW cavity-backed array element is implemented with physically connected stacked patch. The coaxial pin is directly connected to the two patch radiators. Blind and buried vias were avoided, this work significantly reduces the manufacture cost and complexity. The array features light weight and simple feed structure. The proposed element exhibits an impedance-matching bandwidth of 18.2% (14.5–17.4 GHz) for | S 11| H -plane with 8% bandwidth (14.4–15.6 GHz), under the criterion of active voltage standing- wave ratio (VSWR) ≤ 3. For verification purposes, a 4 × 16 active phased array antenna prototype is fabricated using the conventional microwave multilayer printed circuit board (PCB) process. The measured results agree very well with simulations.

Wide-angle scanning linear phased arrays based on wide-beam magneto electric dipole antenna

Microstrip phased array has aroused interest of many researchers because of its beam agility. However, a big problem for typical microstrip array is that its main beam can only scan from about –50° to 50°, with a gain loss of 4-5 dB. Meanwhile, the relatively narrow operating bandwidth of microstrip antenna is also a problem in application. These flaws have dramatically limited its applications and spawned many studies on phased array with wide-angle scanning capability. Several methods have been proposed to broaden the scanning coverage of phased array, such as utilizing pattern-reconfigurable antenna as an element of array, taking wide-beam antenna as the element of array, and adopt metasurface as the top cladding of array. However, most of existing researches mainly focus on achieving wide-angle scanning performance within a relatively narrow bandwidth. A phased array that possesses wide-angle scanning capability at both main planes within a relatively wide bandwidth is highly desirable. In this paper, a wide-beam magnetoelectric (ME) dipole antenna is proposed. It consists of an ME dipole antenna in the form of microstrip patch and a pair of magnetic dipoles. Metallic through holes integrated with patches and ground are utilized to form magnetic currents. Extra magnetic dipoles are added to broaden the 3-dB beam-width. The simulated results reveal that the 3-dB beam-width of the proposed antenna is greater than 107° in the E-plane (9 GHz–12 GHz) and 178° in the H-plane (7 GHz–12 GHz) respectively. The impedance bandwidth of the proposed antenna is 53.26% from 7.3 GHz to 12.6 GHz (VWSR &lt; 2). Based on the proposed antenna element, two linear phased arrays are fabricated and measured. To test the wide-angle scanning capability of the arrays, each antenna element is simply fed with alternating currents with identical amplitude and linearly increasing phases. The measured results reveal that the wide-angle scanning capability of H-plane array and E-plane array can be obtained from 9 GHz to 12 GHz. The scanning beam of the H-plane array can cover the range from -90° to 90°. The scanning beam of the E-plane array can cover the range from –70° to 70°. The impedance bandwidth of the central antenna is 27.03% for the H-plane array from 9.6 GHz to 12.6 GHz (active VWSR &lt; 2.5) and 36.36% for the E-plane array from 9 GHz to 13 GHz (active VWSR &lt; 2) respectively. Hence, the proposed method can be used as a reference for designing a wide-beam antenna and wide-angle scanning phased array and the designed phased arrays can be applied to X-band radar systems.