A 38 dB Gain, Low-Loss, Flat Array Antenna for 320–400 GHz Enabled by Silicon-on-Insulator Micromachining

Abstract

Two high-gain flat array antenna designs operating in the 320-400 GHz frequency range are reported in this article. The two antennas show the measured gains of 32.8 and 38 dBi and consist of a 16 × 16 (256) element array and a 32 × 32 (1024) element array, respectively, which are fed by a corporate H-tree beamforming network. The measured operation bandwidth for both antennas is 80 GHz [22% fractional bandwidth (FBW)], and the total measured efficiency is above −2.5 dB and above −3.5 dB for the two designs in the whole bandwidth. The low measured loss and large bandwidth are enabled by optimizing the designs to the process requirements of the silicon on insulator (SOI) micromachining technology used in this article. The total height of the antennas is 1.1 mm (1.2 λ at the center frequency), with sizes of 15 mm × 18 mm and 27 mm × 30 mm for both arrays. The antennas are designed to be directly mounted onto a standard WM-570 waveguide flange. The design, fabrication, and measurements of eight prototypes are discussed in this article and the performance of the antennas compared to the simulated data, as well as manufacturability and fabrication repeatability are reported in detail.

Millimeter-Wave Multiplexed Wideband Wireless Link Using Rectangular-Coordinate Orthogonal Multiplexing (ROM) Antennas

“…Different from OAM multiplexing, ROM multiplexing does not require software processing and is one of the most attractive candidates for achieving multiplexing at several hundred GHz bands. The required antennas can be fabricated by micromachining and have shown high-efficiency characteristics at several hundred GHz [28].…”

Design of an Amplitude-Tapered Corporate-Feed Slot Array Antenna with Reduced Side-Lobe Level for Silicon Micromachining

“…Array Antenna The first step of designing the array antenna is to design its unit cell [19]. The unit cell consists of 2 × 2 aperture antennas matched to free space impedance and has a low reflection of -18.5 dB at 230-290 GHz, and its gain is 14 dBi at 260 GHz.…”

“…These apertures are fed by a cavity that is directly beneath them. The cavity itself is fed via a slot placed at the bottom of the cavity [19]. The aperture spacing is 0.74𝜆 at centre frequency and is optimized for reducing the grating in the radiation pattern.…”

“…The unit cell element is composed of 2 × 2 element apertures. For balanced corporate feed network antennas [19] the typical side lobe level is around 13 dB which is not satisfactory for point-to-point communication links; however, with precise manipulation of the feed network, an unelevated sidelobe level antenna with preserved total efficiency is achievable as demonstrated in this paper by a novel phase-compensated feed network implemented for large bandwidth.…”

Bandwidth Enhancement of Millimeter-Wave Large-Scale Antenna Arrays Using X-Type Full-Corporate Waveguide Feed Networks

“…For the widely used fullcorporate feed networks with an H-type topology [10], [15], T-junctions operating as cascaded power dividers played a crucial role in the bandwidth improvement. Additional metallic pins [31]- [32] and irises [20], [33]- [34] were employed in the design of H-plane substrate-integrated and air-filled waveguide T-junctions to extend their operating bandwidths. Meanwhile, stepped or tapered waveguide structures are another kind of scheme to improve the impedance matching of both E-plane [16], [35] and H-plane [36] waveguide T-junctions.…”