Bevan Jones

Bio: Bevan Jones is an academic researcher from University of Technology, Sydney. The author has contributed to research in topics: Dipole antenna & Antenna (radio). The author has an hindex of 5, co-authored 11 publications receiving 109 citations.

Suppression of Cross-Band Scattering in Multiband Antenna Arrays

Abstract: This paper presents a novel method of suppressing cross-band scattering in dual-band dual-polarized antenna arrays. The method involves introducing chokes into low-band (LB) elements to suppress high-band (HB) scattering currents. The experimental results show that by inserting LB-pass HB-stop chokes into LB radiators, suppression of induced HB currents on the LB elements is achieved. This greatly reduces the pattern distortion of the HB array caused by the presence of LB elements. The array considered is configured as two columns of HB antennas operating from 1.71 to 2.28 GHz interleaved with a single column of LB antennas operating from 0.82 to 1.0 GHz. The realized array with choked LB element has stable and symmetrical radiation in both HB and LB.

Scattering Suppression in a 4G and 5G Base Station Antenna Array Using Spiral Chokes

Abstract: This letter presents a novel distributed choking technique, the spiral choke, for scattering suppression in dual-band antenna arrays. The working principle and the scattering suppression capability of the choke are analyzed. The spiral chokes are implemented as low-band radiators in a colocated 4G and 5G dual-band array to suppress cross-band scattering while broadening the bandwidth of the choked element. The experimental results demonstrate that the cross-band scattering in the array is largely eliminated, and the realized dual-band array has very stable radiation performance in both well-matched bands.

A Wideband Base Station Antenna Element With Stable Radiation Pattern and Reduced Beam Squint

Abstract: This paper presents the design procedure, optimization strategy, theoretical analysis, and experimental results of a wideband dual-polarized base station antenna element with superior performance. The proposed antenna element consists of four electric folded dipoles arranged in an octagon shape that are excited simultaneously for each polarization. It provides ±45° slant-polarized radiation that meets all the requirements for base station antenna elements, including stable radiation patterns, low cross polarization level, high port-to-port isolation, and excellent matching across the wide band. The problem of beam squint for beam-tilted arrays is discussed and it is found that the geometry of this element serves to reduce beam squint. Experimental results show that this element has a wide bandwidth of 46.4% from 1.69 to 2.71 GHz with ≥15-dB return loss and 9.8 ± 0.9-dBi gain. Across this wide band, the variations of the half-power-beamwidths of the two polarizations are all within 66.5° ± 5.5°, the port-to-port isolation is >28 dB, the cross-polarization discrimination is >25 dB, and most importantly, the beam squint is <4° with a maximum 10° down-tilt.

Wideband Dual-Polarized Multiple Beam-Forming Antenna Arrays

Abstract: Wideband multibeam antenna arrays based on three-beam Butler matrices are presented in this paper. The proposed beam-forming arrays are particularly suited to increasing the capacity of 4G long-term evolution (LTE) base stations. Although dual-polarized arrays are widely used in LTE base stations, analog beam-forming arrays have not been realized before, due to the huge challenge of achieving wide operating bandwidth and stable array patterns. To tackle these problems, for the first time, we present a novel wideband multiple beam-forming antenna array based on Butler matrices. The described beam-forming networks produce three beams but the methods are applicable to larger networks. The essential part of the beam-forming array is a wideband three-beam Butler matrix, which comprises quadrature couplers and fixed wideband phase shifters. Wideband quadrature and phase shifters are developed using striplines, which provide the required power levels and phase differences at the outputs. To achieve the correct beamwidth and to obtain the required level of crossover between adjacent beams, beam-forming networks consisting of augmented three-beam Butler matrices using power dividers are presented to expand the number of output ports from three to five or six. Dual-polarized, three-beam antenna arrays with five and six elements covering LTE band are developed. Prototypes comprising beam-forming networks and arrays are tested according to LTE base station specification. The test results show close agreement with the simulation ones and compliance with LTE requirements. The designs presented are applicable to a wide range of wideband multibeam arrays.

Suppression of Cross-Band Scattering in Interleaved Dual-Band Cellular Base-Station Antenna Arrays

Abstract: In this article, novel techniques to suppress cross-band scattering in interleaved dual-band base station antenna arrays are presented. Firstly, the detrimental effect of high-band (HB) elements on low-band (LB) radiation performance is theoretically analyzed. With a thorough analysis, a capacitance-loaded HB element is innovated to solve the issue and restore the LB patterns. Secondly, to eliminate the reverse HB scattering caused by the LB element while enhancing the bandwidth of the LB element, a novel double-arm choked cross-dipole configuration is proposed. A compact array section is built with these innovated elements. The experimental results of the array show a largely suppressed cross-band scattering with stable radiation performance across the well-matched bands, demonstrating the effectiveness of the presented techniques.

Suppression of Cross-Band Scattering in Multiband Antenna Arrays

Abstract: This paper presents a novel method of suppressing cross-band scattering in dual-band dual-polarized antenna arrays. The method involves introducing chokes into low-band (LB) elements to suppress high-band (HB) scattering currents. The experimental results show that by inserting LB-pass HB-stop chokes into LB radiators, suppression of induced HB currents on the LB elements is achieved. This greatly reduces the pattern distortion of the HB array caused by the presence of LB elements. The array considered is configured as two columns of HB antennas operating from 1.71 to 2.28 GHz interleaved with a single column of LB antennas operating from 0.82 to 1.0 GHz. The realized array with choked LB element has stable and symmetrical radiation in both HB and LB.

Quasi-Optical Multi-Beam Antenna Technologies for B5G and 6G mmWave and THz Networks: A Review

Abstract: Multi-beam antennas are critical components in future terrestrial and non-terrestrial wireless communications networks. The multiple beams produced by these antennas will enable dynamic interconnection of various terrestrial, airborne and space-borne network nodes. As the operating frequency increases to the high millimeter wave (mmWave) and terahertz (THz) bands for beyond 5G (B5G) and sixth-generation (6G) systems, quasi-optical techniques are expected to become dominant in the design of high gain multi-beam antennas. This paper presents a timely overview of the mainstream quasi-optical techniques employed in current and future multi-beam antennas. Their operating principles and design techniques along with those of various quasi-optical beamformers are presented. These include both conventional and advanced lens and reflector based configurations to realize high gain multiple beams at low cost and in small form factors. New research challenges and industry trends in the field, such as planar lenses based on transformation optics and metasurface-based transmitarrays, are discussed to foster further innovations in the microwave and antenna research community.

Dual-Band Shared-Aperture Base Station Antenna Array With Electromagnetic Transparent Antenna Elements

Abstract: An electromagnetic transparent antenna element is proposed for dual-band shared-aperture fifth-generation (5G) MIMO base station antenna array developments. The antenna element that operates in the low-frequency band (LB) of 1.8–2.7 GHz is placed above the aperture of the antenna array that operates in the high-frequency band (HB) of 3.3–3.8 GHz. Because of this antenna array configuration, the antenna elements in the LB have to be transparent to the electromagnetic waves radiated by the HB antenna array. This kind of electromagnetic transparent antenna element allows the HB antenna array working properly in the dual-band shared-aperture antenna array configuration. In this work, the electromagnetic transparent antenna element is inspired by the element of a typical wide-angle bandpass frequency selective surface (FSS). The radiation performance of the electromagnetic transparent antenna element at the LB is realized by properly combining the wide-angle bandpass FSS elements. A dual-band dual-polarized shared-aperture antenna array is then developed to demonstrate the concept and design. The experimental result validates the stable radiation patterns of each antenna element in both LB and HB. It indicates the proposed approach is promising for 5G MIMO base station antenna array developments.

Compact Dual-Polarized Shared-Dipole Antennas for Base Station Applications

Abstract: Crossed-dipole (CD) antennas have been widely employed for dual polarization in wireless communication systems in recent years. In this paper, a novel design concept of dual-polarized shared-dipole (DPSD) antenna is presented. Different from the traditional CD antennas, the arms of the DPSD antenna are shared for two orthogonal polarizations. This design technique leads to significant size reduction and high isolation compared to the traditional CD antennas. The operation principle of the proposed antenna is theoretically analyzed. To validate the presented design concept, two novel DPSD antennas are designed, fabricated, and measured. The first design is a four-port DPSD antenna, which is a straightforward demonstration of the operation principle of the DPSD antenna. The second design is a highly integrated DPSD antenna, which avoids the use of a feed network and provides a simple configuration to design the dual-polarized antenna. Both of the DPSD antennas are designed to operate at 1.7–2.7 GHz for base station applications. The simulated and measured results confirm that the two DPSD antennas have wide bandwidth with VSWR 35 dB dB. In addition, stable gain and half-power beamwidth are obtained with the variance less than ±0.55 dB and ±3.5°, respectively.

Scattering Suppression in a 4G and 5G Base Station Antenna Array Using Spiral Chokes

Abstract: This letter presents a novel distributed choking technique, the spiral choke, for scattering suppression in dual-band antenna arrays. The working principle and the scattering suppression capability of the choke are analyzed. The spiral chokes are implemented as low-band radiators in a colocated 4G and 5G dual-band array to suppress cross-band scattering while broadening the bandwidth of the choked element. The experimental results demonstrate that the cross-band scattering in the array is largely eliminated, and the realized dual-band array has very stable radiation performance in both well-matched bands.