A Novel High-Gain Sum and Difference Conical Beam-Scanning Reflector Antenna

Abstract

A novel sum and difference (SD) conical beam-scanning reflector antenna is proposed in this paper. The reflector surface, illuminated by two omnidirectional horns, is a body of revolution obtained by revolving the generating parabola about a symmetry axis. The horns stacked along the symmetry axis of the reflector are fed by a nest coaxial waveguide. Teflon lens is used to improve the side lobe levels and reflection coefficients of the feed horns. By tilting the generating parabola and using the offset feeding method, two conical beams, with different beam pointing angles, were generated. A compact feed network was also designed to feed the two horns, which includes two rectangular TE10 mode-to-coaxial TEM mode transitions and a Magic-T to implement SD beams. The scanning performance of conical beams can be achieved by mechanically moving the feed antennas along the symmetry axis and taking full advantage of offset focus characteristic of the parabolic reflector. The error in angle measurement was also discussed. The SD conical beam-scanning antenna was formed by a parabolic dish with a radius of 18 λ operating at 24 GHz. The proposed antenna was designed, simulated, and fabricated. The measured results show that the difference beam null-depth is −25 dB and the sum beam gain is 15 dBi at 40°. The sum beam gain varies by less than 1.5 dB across the scan coverage from 30.8° to 45.2°. The measured results are found to be in good agreement with the simulated ones. INDEX TERMS Reflector antenna, conical beam, magic-T, sum and difference beams I. INTRODUCTION Of late, much attention has been paid to conical beam antennas, because they are good candidates for satellite communication, target detection, tracking or guiding system, and so on. Conical beam antennas are superior to phased array antennas and omnidirectional antennas in TACAN-tactical air navigation system, vehicles communication, etc., because of their low cost and better performance. Satcom on the Move (SOTM) system needs high-gain and wide-beam coverage to obtain good quality communication [1]. The conical beam-scanning antennas with sum and difference beams for tracking capability can give better performance-to-cost ratio. Different from the traditional pencil beam monopulse antennas [2]-[4], the beam coverage of conical beam antenna is a ring area rather than a spot area. Therefore, conical beam antennas have intrinsic advantage of being wide beam coverage that is very important in many applications. Consequently, unlike the pencil beam the gain reaches 15dBi

Dual-Polarization and Dual-Band Conical-Beam Array Antenna Based on Dual-Mode Cross-Slotted Cylindrical Waveguide

“…In any case, despite the considerable antenna size, end user usage could be envisaged when possible. For instance, a reasonable possibility would be the installation of the conical-beam antenna on a vehicle, thus able of establishing communication with satellite links [22].…”

“…They have been used in several applications such as remote sensing, satellite or mobile communications. For example, on-board antennas in vehicles for navigation satellite communications or satellite tracking require widebeam coverage to follow the satellite trajectory over the sky [19]- [22]. Due to the integration of satellite and terrestrial networks in the new 5G system, satellite communications play an important role in the extension of 5G mobile networks to hard-to-reach areas or high-mobility scenarios (such as airplanes or trains).…”

“…In fact, gain values higher to 10 dBi can be considered a design challenge. To the best of authors' knowledge, only some few works have achieved a very high-gain performance for conical-beam antennas: a Ka-band omnidirectional high-gain bicone antenna of approximately 12.5 dBi in [33]; an annular planar leakywave antenna of 15 dBi in [34]; some conical-beam coaxial horn antenna designs for dual/single band in [35] and a conical-beam parabolic reflector antenna fed by two omnidirectional horns in [22], which obtains a maximum gain of 14.9 dBi. Regarding waveguide technology, a small low-directive omnidirectional circularly polarized antenna was firstly introduced in [36] by the authors for space vehicle communications at 37 GHz.…”

Comparative Analysis on the Effect of Surface Reflectance for Laser 3D Scanner Calibrator

“…Non-contact measurement technology is widely used, especially for large-scale workpiece measurement, such as propeller blade [1], antenna reflector [2], cabin capacity [3][4], vertical metal container, etc. It can realize long-distance, high-precision and fast measurement for large-scale objects, which avoids interfacial contact and possible deformation in the measurement.…”

A PSO-CVX Algorithm of Sum and Difference Beam Patterns for Time-Modulated Antenna Array

“…Only the phase shift is required to switch the half-array between the two radiation modes and the sparsity of the array layout can be achieved by appropriately using the principle of compressed sensing [27]. In addition to algorithmic improvements, many people have conducted research on hardware aspects such as antenna design and optimized the sum and difference beam pattern [2,[28][29][30].…”