140 GHz Small Horn-type Antenna with Sanchez's Ridge Waveguide

This paper describes Sanchez's ridge waveguide (SRWG), and small horn-type antennas that are fed by the SRWG. The SRWG was manufactured by a resin injection molding method (high productivity, low cost) and a CNC milling method (precision, high cost). Although the injection molding method results in rounded edges, it was confirmed that the same performance as the CNC milling method can be obtained by optimizing the shape. Next, small horn-type antennas for 140 GHz, which were assumed to be integrated into the SRWG, were considered. One was a pyramidal small horn-type antenna and the other was a quadrate small horn-type antenna. The apertures were designed to have a short side of approximately 2 mm considering array antenna integration. The maximum gain was 13.2 dBi with direct waveguide feeding and 12.7 dBi via SRWG.