Beam-steering Antenna Research Articles

IEEE AWPL Special Cluster 2022 on “Disruptive Beam-Steering Antenna Technologies for Emerging and Future Satellite Services”

IEEE AWPL Special Cluster 2022 on “Disruptive Beam-Steering Antenna Technologies for Emerging and Future Satellite Services”

A beam steering antenna based on Fresnel zone plate radome

In this study, a beam steering antenna was presented, comprising patch antenna and two layers of Fresnel zone plate (FZP). One of the FZP was a fixed structure, the other was a 1-D collapsible radome with alternately deployed metal strips covering and non-covering regions. The two sets of FZP were arranged in order in front of the patch antenna. First, the beam was compressed vertically by the fixed FZP. Subsequently, the beam steering was achieved with the use of the collapsible radome by setting the folding status in the respective region. To assess the effectiveness of the method, a 1-D beam steering antenna working at 3 GHz was designed by applying linear polarized patch antenna as the feeding source. The collapsible FZP structure was developed using a low-loss fiberglass cloth that was covered with copper strips. Based on the simulation and the experiment, the beam was focused to a beam width of 30° vertically and 10° horizontally. Moreover, 60° of beam steering in the horizontal direction could be achieved by regulating the folding angles in the respective region. This antenna design was found to be light weight and flexible, which has promising applications in 5G cell coverage and satellite communication.

A novel approach for design of beam steerable aperiodic planar array antenna with reduced number of elements

This paper introduces the design of an aperiodic beam steerable planar array antenna using a novel strip-projection (SP) method, offering the reduced array elements with improved peak SLL with beam scan. The SP method generates the aperiodic lattice by projecting a section of the 3D body-centric tetragonal lattice onto the aperture and rotating it using Rodrigue's formula. The optimized lattice parameters are obtained using Jaya algorithm. The proposed SP method requires only three optimization parameters for any aperture dimensions and 21.9% less elements as compared to the rectangular lattice. For comparison, pinwheel-based aperiodic planar array antenna has been designed and analyzed. The peak SLL is maintained <−11.63 dB and <−12.70 dB for 0°-30° beam scan by proposed array and pinwheel-based array respectively. Both types of aperiodic lattice have been populated with S-band dielectric resonator antenna and simulated. Position standard deviation has also been introduced and computed to quantify the aperiodic distribution.

Beam‐steering transmitarray with active frequency selective surface for wireless power transmission

This letter presents a beam-steering antenna with an active frequency selective surface (AFSS). The proposed AFSS-based antenna consists of a source antenna and an active frequency selective surface as a superstrate. The AFSS unit consists of three layers, where the upper and lower layers are identical and the middle layer has a slight variation. This structure makes it possible to obtain 360° phase variation, which can be achieved by changing the bias voltage at both ends of the varactor diodes in the case of three layers. Its passband is about 40 MHz (from 5.14 to 5.18 GHz). Finally, the proposed unit cell was stacked into a 5 × 5 array; both simulated and measured results demonstrated that the transmitarray has the scan ability of ± 25° at 5.16 GHz. The proposed transmitarray is suitable for dynamic wireless power transmission.

Graphene-based terahertz closed-stopband tunable composite right/left-handed leaky-wave antennas

A simple scheme for the realization of the terahertz (THz) fundamental-mode tunable closed-stopband composite right/left-handed leaky-wave antennas (CRLH LWAs) is presented. The proposed CRLH LWAs are reconstructed by graphene-based coplanar waveguide (CPW) transmission line supercells. Their shunt inductances achieved by narrow graphene strips of two unit cell structures are halved. The CRLH LWAs are designed and confirmed by numerical simulations. They also exhibit frequency-scanning behaviors at THz with narrower bandwidth than that of the conventional graphene-based fundamental-mode CPW unit cell CRLH LWAs at THz. Besides, the LWAs also exhibit strong tunable characteristics and achieve the closed-stopband condition more effectively. Therefore, the proposed supercell CRLH LWAs could further improve the performance of the beam-steering antennas at THz.

Low Profile Beam Steerable Antenna using PI Axis Posts for Massive-MIMO 5G Applications

5G networks promised to provide increased coverage, capacity and end-user throughput. Advanced antenna radiating system plays a very important role for the establishment of 5G networks. In this work, a novel low size profile enforced terminating boundary patch antenna array is proposed. This antenna array achieves a Hybrid beam steering with a low size through PI axis posts up to 33%. The antenna has a three-layer structure where a single layer PTFE composite based Rogers 5880 is utilized with a dimension of 15× 16 mm2. It operates at frequency band of 35 GHz with a wide bandwidth of 530 MHz and with a mean return loss of -28 dB. This radiating device is designed with the microstrip feed for the massive-MIMO 5G requirements.

A Survey on Beam Steering Techniques in Printed Antennas

&lt;span&gt;Beam steering antennas is essential part of various WCN (Wireless Communication Networks) such as radar and satellite communication. The increasing demand of high data rate, high SNR (Signal to Noise Ratio) and high gain, therefore pattern reconfigurable antennas are required to improve such properties. &lt;/span&gt;&lt;span&gt;Beam steering is the technique of changing the main lobe direction of radiation. The constructive and distractive interference are used to steer the lobe in specific direction. Beam steering is necessary in various communications such as localization, satellite, tracking system and airborne application.&lt;/span&gt;&lt;span&gt; Beam steering antenna decreases interference and power consumption and also increases directivity and gain. Beam steering antenna transmit and receive signals in specific direction. &lt;/span&gt;&lt;span&gt;Beam steering antenna decreases interference and power consumption and also increases directivity and gain. The researchers are interested to find optimal beam steering solution for single and multi-point application. &lt;/span&gt;&lt;span&gt;In past various techniques are used to achieve beam reconfigurable antennas. This paper presents, beam steering principle and their theory, beam steering techniques such as; Mechanical Steering, Beamforming, Switching Pin Diodes, Reflector and array antenna (Reflectarray), Parasitic Steering, Phase Shifters, Switched Beam Antennas, Metamaterial Antennas, Traveling Wave Antennas, Retro-directive Antennas, Integrated Lens Antennas (ILAS), merits and demerits and comparison among various techniques.&lt;/span&gt;

Multi-user accessible indoor infrared optical wireless communication systems employing VIPA-based 2D optical beam-steering technique.

Infrared optical wireless communication system can achieve ultrahigh capacity and high privacy data transmission. However, for using narrow infrared laser beam as carrier to transmit signal, the high-speed data transmission can only be achieved by point-to-point connection. With the rapid number increasement of consumer electronic devices, such connection method puts a heavy burden on the number of transmitters. Thus, the transmitting end with the point-to-multipoint capability or multi-user accessibility is required. In this paper, we present a multi-user accessible indoor infrared optical wireless communication system employing passive diffractive optics based on a virtually imaged phased array (VIPA). Multiple beams can be generated in a point-to-multipoint scheme by using VIPA-based beam-steering antenna (BSA). On the other hand, by tuning wavelength of laser source, fast 2D steering of multiple beams with the same steering trajectory is supported, which can be used for user ends with changing locations. In the experiment, 5 beams are generated by utilizing only one transmitter. All five beams can realize 12.5 Gb/s on-off-keying (OOK) data rate transmission. Free-space optical wireless transmission at 3.6-m communication distance is demonstrated for system performance verification and evaluation. a total 3.44°×7.9° scanning field of view of five beams is achieved.

Compact beam‐switchable antenna for mm‐wave 5G handheld devices

An electronically beam-steerable antenna (BSA) is envisioned. The presented BSA is a possible solution to overthrow the limitations inherent to phased antenna arrays. The design consists of a gap coupling inset feed rectangular patch (driven element) and 3 × 1 passive parasitic patches deployed on both sides of the driven patch. Prototype having 20 × 20 mm dimensions is printed on Rogers® RT/duroid®5870. Four switches are used to load the reactive impedance on parasitic patches, which in turn, change the phases of surface current on parasitic elements and the driven element. Based on the different ON and OFF configuration of switches in parasitic array elements, the main beam is steered along with different directions. The simulated results show that the design can operate between 26.8 and 30.3 GHz a wide impedance bandwidth |S11|< −10 dB (12.5%) with a peak gain of 8.9 dBi and wide 3-dB scanning angle that is, −37° to 156° in the azimuth plane. The exhibited performance of BSA with favourable characteristics, such as wideband, adequate gain, wide-angle beam switching, and low profile renders the BSA a good candidate for 5G millimetre wave handheld devices. Moreover, to corroborate the performance, the design is fabricated, and experimental measurements were performed. Congruence is observed between the experimentally measured and computationally simulated results. The simulated results of spherical coverage analysis of BSA with the integration of smartphone form factor are also presented.

Air-bridged Schottky diodes for dynamically tunable millimeter-wave metamaterial phase shifters

A low loss metamaterial unit cell is presented with an integrated GaAs air-bridged Schottky diode to produce a dynamically tunable reflective phase shifter that is capable of up to 250° phase shift with an experimentally measured average loss of 6.2 dB at V-band. The air-bridged Schottky diode provides a tuneable capacitance in the range between 30 and 50 fF under an applied reverse voltage bias. This can be used to alter the resonant frequency and phase response of a split patch unit cell of a periodic metasurface. The air-bridged diode die, which is flip-chip soldered to the patch, has ultra-low parasitic capacitance and resistance. Simulated and measured results are presented which verify the potential for the attainment of diode switching speeds with acceptable losses at mmWave frequencies. Furthermore the study shows that this diode-based unit cell can be integrated into metamaterial components, which have potential applications in future mmWave antenna beam-steering, intelligent reflecting surfaces for 6G communications, reflect-arrays, transmit-arrays or holographic antennas.

Terahertz Quasi-TEM Mode Tunable Composite Right/Left-Handed Leaky-Wave Antennas Using Graphene-Based Coplanar Waveguides

A novel and simple scheme for the realization of the terahertz (THz) fundamental-mode composite right/left-handed leaky-wave antennas (CRLH LWAs) is proposed. The CRLH LWAs are reconstructed by graphene-based coplanar waveguide transmission line (CPW TL) unit cells. Their signal lines are grounded by narrow graphene strips to achieve the shunt inductances, and parallel-plates are periodically added along the signal line to obtain the series capacitances. The propagation properties of the LWAs are detailed. The LWAs have both left-handed (LH) and right-handed (RH) regions by varying frequency. By numerical simulations, the LWAs are verified. Their backfire-to-endfire beam-steering capabilities through frequency scanning are confirmed. Compared with the CRLH LWAs at THz proposed in previous literature, the graphene-based CRLH LWAs operate in the Quasi-TEM mode. They possess low fabrication, excitation, and impedance matching difficulty. They also show the possibility of integration with other micro-devices. With the application of graphene, the LWAs exhibit strong tunable characteristics that conventional CRLH LWAs are absent. Therefore, the proposed CRLH LWAs have great potential applications for the development of beam-steering antennas at THz.

A novel high power frequency beam-steering antenna array for long-range wireless power transfer

A novel passive frequency beam-steering linear antenna array is proposed in this paper to be utilized at the transmit side of a long-range wireless power transfer (WPT) system. To assure high power handling for a long-range transfer, the proposed antenna is designed based on stripline technology. Moreover, unlike other reported designs, the antenna array in this paper uses parallel feed while frequency beam-steering. This permits to apply a special synthesis at the radiating elements to minimize the energy wasted at the side lobes. The antenna array uses common-fed dipoles as radiating elements to eliminate the surface current at the ground planes that is considered a critical issue in high power applications. The antenna covers the frequency band from 1.1 to 1.5 GHz with a reflection coefficient better than −10 dB (VSWR < 2). Consequently, steers its main lobe from 60° to 90° respectively. Being passive, the efficiency of the WPT system is improved as no active component is needed to steer the antenna beam. The antenna is capable of radiating simultaneous, sequential or selective (shuffled) multiple beams for multiple receivers with a half-power beamwidth of 6°, a peak-to-side lobe level better than 20 dB and an average realized gain of 13 dBi. The antenna array handles a peak power reaches 1.6 MW which makes it an excellent candidate for a long-range WPT system.

Dual-band beam steering THz antenna using active frequency selective surface based on graphene

A dual-band independently beam steering THz antenna is presented, which is composed of a broadband omnidirectional monopole source antenna surrounded by six hexagonal active frequency selective surface (AFSS) screens with switchable filtering response in two bands. By controlling the chemical potential from 0 eV to 0.5 eV, the AFSS screen can achieve the conversion between high transmission (ON state) and almost total reflection (OFF state) at two frequency ranges independently. Therefore, the radiation beams of the THz antenna in two bands can be steered from 360° large angle scanning and omnidirectional radiation with flexible combinations.

Flat-Panel Mechanical Beam Steerable Array Antennas With In-Plane Rotations: Theory, Design and Low-Cost Implementation

We present a compact, flat-panel phased-array antenna design that beam steers using only mechanical in-plane rotations. We explain the steering mechanism and characterize the beam analytically and numerically. Measurements of two prototype antennas for different frequencies validate the concept and modeling. The prototype designs are described in detail and feature added phase-offset control of the array elements in the aperture layout. Potential applications include low-cost and low-power flat-panel user terminals for the next generation of aerial and space communication systems.

Dual-Polarized High-Isolation Antenna Design and Beam Steering Array Enabling Full-Duplex Communications for Operation Over a Wide Frequency Range

A new dual-polarized antenna and array are presented for In-Band Full-Duplex (IBFD) applications, offering high inter-port isolation. The single-element antenna system consists of four H-shape slots, stacked patches for wide bandwidth, and two external hybrid couplers. The multilayer antenna is well matched from about 2.1 to 2.4 GHz and provides high isolation in this frequency range in excess of 60 dB. Two different prototypes are simulated and measured to highlight the design process. In addition, a new and compact hybrid coupler with excellent phase and magnitude stability is also presented for improved antenna radiation and IBFD performances. When compared to other similar types of hybrid coupler and antenna systems, the proposed configurations are simple to manufacture, provide a higher isolation bandwidth (10%), and higher gain of 7.3 dBi with cross-polarization levels of 30 dB or lower. The single-element design was also extended to a 2×2 array and studied for different beam steering and feeding scenarios. The operating bandwidths and isolation values offered by these S-band antenna and array systems can support new data link possibilities for beam steering and future low-cost IBFD wireless networks by simple antenna fabrication.

Graphene-based Terahertz closed-stopband composite right/left-handed leaky-wave antennas

A simple scheme for the realization of the terahertz (THz) fundamental-mode closed-stopband composite right/left-handed leaky-wave antennas (CRLH LWAs) is presented. The proposed CRLH LWAs are reconstructed by graphene-based coplanar waveguide (CPW) transmission line supercells. Their shunt inductances achieved by narrow graphene strips of two unit cell structures are halved. The CRLH LWAs are designed and confirmed by numerical simulations. They also exhibit frequency-scannable behaviors at THz with narrower bandwidth than that of the conventional graphene-based fundamental-mode CPW unit cell CRLH LWAs at THz without stopbands. Therefore, the proposed supercell CRLH LWAs could further improve the performance of the beam-steering antennas at THz.

Fixed-Frequency Beam-Steering Using Slotted Waveguide With Tunable Impedance Walls

In this paper, we describe the development of a new beam-steerable antenna array using a reconfigurable waveguide with tunable impedance side walls. The array has 36 radiating elements placed on the top wall of the waveguide and a common biasing voltage for tuning the impedance walls. The antenna operates at 9.3 GHz and its beam can be steered from 22° to 65° by changing the bias voltage from 16 to 7 volts. The gain of the antenna remains within the 3 dB limit of the maximum gain of 11.8 dB throughout the steering range. The effective radiating length of the antenna is $13\lambda $ and its half-power beamwidth is 5°. For this frequency range and electrical length, this antenna has a high radiation efficiency. This is due to the phase-shifting mechanism used which results in the varactor loss being less than all other sources of loss throughout most of the steering range. This makes the antenna suitable for applications where the varactors should operate at high frequencies with relatively low quality factors.

An Extended Two Step Approach to High-Resolution Airborne and Spaceborne SAR Full-Aperture Processing

The processing of synthetic aperture radar (SAR) echoes collected during radar antenna beam steering, such as in the staring spotlight, sliding spotlight, and TOPS operating modes, requires additional efforts due to the limited pulse repetition frequency (PRF). Subaperture processing is mostly used in these cases, but the complexity arising from subaperture dividing and recombination is preferably avoided. The two-step approach (TSA) is an elegant solution to full-aperture processing. Nevertheless, for high-resolution airborne and spaceborne SAR processing, the TSA is still faced with a number of difficulties, which does not occur, however, in subaperture processing. For instance, the high range bandwidth induces Doppler spectrum aliasing during the spectral analysis (SPECAN) stage of the original TSA. Moreover, the Doppler spectrum obtained in TSA, when inverse Fourier transformed back to the slow time domain, might also suffer from aliasing, which precludes the estimation and correction of the unknown residual motion error or tropospheric disturbance. In this article, we extend the TSA to address these problems and present a full-aperture processing framework to precisely focus the high-resolution airborne and spaceborne SAR data. Simulation of X-band spaceborne SAR echoes with transmission signal bandwidth of 3.6 GHz and coherent integration angle of 12.5° has validated the extended TSA (ETSA). Meanwhile, experimental X-band airborne SAR data with the same range and azimuth resolution are also processed using the ETSA, where the conventional autofocusing techniques have been smoothly incorporated.

A novel high-power waveguide phase shifter with continuous linear phase adjustment.

A novel all-metal phase shifter with continuous linear phase adjustment for high-power microwave applications is presented and tested in this paper. The phase adjustment is achieved through the rotation of a phase reverser for a circularly polarized wave, and the output phase accomplishes a phase adjustment range of 360° by rotating the phase reverser for 180°. Due to the symmetrical characteristics, its position after rotating 180° is the same as the initial position, which can achieve continuous phase adjustment and avoid phase mutation. Simulation results indicate that the phase shifter achieves the transmission efficiency greater than 99.90% at a center frequency of 8.4 GHz, and the bandwidth of transmission efficiency greater than 98.00% is up to 50 MHz. Experiments are carried out and the measured results are in good agreement with simulation. To sum up, the power capacity of this phase shifter is estimated to be more than 80 MW under vacuum conditions (<10-3 Pa), and it can be applied to fast continuous high-power beam-steerable antenna arrays or mode conversion systems.

3D Beam Steering End-Fire Helical Antenna With Beamwidth Control Using Plasma Reflectors

In this article, a beam steerable antenna based on plasma reflectors is presented. The proposed antenna consists of an axial mode helical antenna surrounded by an array of plasma reflector elements forming a cup-shaped ground. In this configuration, the elements of the reflector array can be individually switched on or off to achieve different radiation characteristics for the helical antenna. Specifically, it is shown that the symmetric activation of a specified number of elements of the plasma array can be used to control the beamwidth of the antenna. Moreover, the plasma reflectors can be asymmetrically configured to steer the endfire beam pattern of the helical antenna in 3-D space. To validate the concept, the proposed antenna is designed and numerically simulated. The simulation results show that using the proposed method, the beamwidth of the proposed antenna can be changed from 37° to 50° while the beam direction can be altered in 3-D space within a solid angle of ±6°. Finally, a prototype of the designed antenna is fabricated and its radiation characteristics for various configurations of the plasma reflectors are measured. Good agreement between the simulation and measurement results validates the proposed method.