Miniature, Conformal, and Spectrally Agile Ultra Wideband Phased Array Antenna for Communication and Sensing

The goal of this research was to develop a highly versatile, integrated communications/remote sensing system, to exhibit ultra-wideband (UWB) operation in the Ka- and mm-Wave bands. This system should enable high data rate satellite communications, as well as a reduction in size, weight, and power consumption over current systems, by consolidating many separate antennas into a shared multi-functional aperture. Over the course of this project, three UWB array apertures were developed, fabricated and measured, spanning 0.5–5 GHz, 3.5–18.5 GHz, and 24–71 GHz, respectively. These represent significant advancements to the state of the art in the areas of low-profile bandwidth, scanning capability, high-frequency operation, and low cost fabrication. Ultra-Wideband, Dual Polarized Array for Multiband Communications at UHF–C Band: Abstract—In space-borne applications, reduction of size, weight, and power can be critical. Pursuant to this goal, we present an ultrawideband, Tightly Coupled Dipole Array (TCDA) capable of supporting numerous satellite communication bands, simultaneously. Such antennas enable weight reduction by replacing multiple antennas. In addition, it provides spectral efficiency by reusing intermediate frequencies for inter-satellite communication. For ease of fabrication, the array is initially designed for operation across the UHF, L, S, and lower-C bands (0.6–3.6 GHz), with emphasis on dual-linear polarization, and wide-angle scanning. The array achieves a minimum 6:1 bandwidth for VSWR less than 1.8, 2.4, and 3.1 for 0˚, 45˚, and 60˚ scans, respectively. The presented design represents the first practical realization of dual polarizations using a TCDA topology. This is accomplished through a dual-offset, split unit cell to minimized inter-feed coupling. Array simulations are verified with measured results of an 8x8 prototype, exhibiting very low cross polarization and near-theoretical gain across the band. Further, we present a TCDA design operating across the upper-S, C, X, and Ku bands (3–18 GHz). The array achieves this 6:1 bandwidth for VSWR < 2 at broadside, and VSWR < 2.6 at 45˚. A discussion on design and fabrication for low-cost arrays operating at these frequencies is included. Ultra-wideband phased array for small satellite communications: Abstract—There is a continuing need for reducing size and weight of satellite systems, particularly in light of recent efforts to increase the functional role of small- and nano-satellites (for instance SmallSats and CubeSats). To this end, a family of arrays is presented, demonstrating ultra-wideband operation across the numerous satellite communications frequencies up to the Ku-, Ka-, and millimetre-wave bands. The first design is demonstrated to operate from 3.5–18.5 GHz with VSWR < 2 at broadside, and validated through fabrication of an 8 × 8 prototype. Additional designs operating from 7–37 and 9–49 GHz, both with VSWR < 2.1 at broadside, are verified via simulations only. These designs are optimised for low cost, using printed circuit board fabrication and appropriate materials selection for space application. E- and H-plane scanning patterns are provided. Finally, multi-physics simulations of the array in high power transmit are conducted. Temperature trends and distribution are given, with the array showing favourable distribution of thermal energy at up to 2 W of RF input power per element, and a peak temperature only 40°C above ambient. Error Correction in Ku-Band Phased Array Measurements: Abstract—Far-field characterization of array antennas can require many sequential measurements. In preparing such measurements, the necessary antenna repositioning and rotation can introduce small displacements. These displacements are not as important at low frequencies, but can be a significant fraction of a wavelength at the Ku-, Ka-, and millimeter wave bands. Therefore, it is important to correct for them to obtain accurate array measurements. In this paper we present a mathematical model, describing the expected phase response of each antenna element for a given physical offset. This error model is applied to Ku band measurements of an 8×8 dipole array. It is demonstrated that small movements of the antenna during measurement can be corrected via the proposed post-processing technique. Ultra-Wideband Phased Array for Millimeter-Wave ISM and 5G Bands, Realized in PCB: Abstract—In this paper we present the design, fabrication, and measurement of an Ultra Wideband (UWB) phased array antenna, with continuous coverage of all six allocated 5G and ISM bands in the millimeter-wave spectrum. Of importance is that the complete array is cofabricated as a single printed circuit board (PCB) using commercial processes, implying a significant reduction in cost over previous micro-fabrication based designs. The design is demonstrated in simulation to operate across 24–72 GHz with VSWR<2.2 at broadside, and VSWR<3 for ±45 degree scanning in all planes. These simulations are validated through the fabrication and measurement of a 3 × 3 array prototype, which shows close agreement to the simulated values.