Millimeter-wave Receiver Optics for Korean VLBI Network

摘要

Over the past several years the millimeter wave VLBI (Very Long Baseline Interferometry) observations have been intensively performed. However phase fluctuation due to troposphere is one of the key issue in terms of degradation of sensitivity and limits imaging capability in millimeter wave VLBI observations. We describe the details of designed receiver optics for the Korean VLBI Network to calibrate tropospheric phase fluctuation for the millimeter wave VLBI observation. These optics guide beams from one position on sky to 22, 43, 86, and 129 GHz-band receivers simultaneously. Several topics, such as the design principles of imaging and power loss due to phase errors on common ellipsoidal mirrors are discussed.