Development of Receiver Optics for ASTE Band 7+8 Receiver

In this study, we propose an optics design for a submillimeter-wave receiver that combines the Atacama large millimeter/submillimeter array (ALMA) Band 7 and Band 8 frequencies (275-500 GHz). To achieve a fractional bandwidth of over 50%, we applied a profiling technique using a cubic spline pattern for a corrugated feedhorn. With two-mirror optics, the near-field beam patterns were measured at 4K. The quasi-optics system, including the feedhorn, exhibited an aperture efficiency of more than 80% over the RF band.