Design of Quasi-optical Circuit for Multi-frequency Millimeter VLBI Receiving System

摘要

Provided are a multi-frequency millimeter-wave very long baseline interferometry (VLBI) receiving system and a method of designing a quasi optical circuit for the multi-frequency millimeter-wave VLBI receiving system. The multi-frequency millimeter-wave VLBI receiving system includes a plurality of low pass filters, offset ellipsoidal mirrors, and flat mirrors for dividing a cosmic radio wave signal incident through the troposphere. A beam propagated from a celestial point is introduced into a receiver room via a 45-degree flat mirror and is divided into a plurality of beams by using a plurality of low pass filters having different bandwidths and mirrors, and the divided beams are transmitted to corresponding quasi-optical receivers having different bandwidths via a plurality of mirrors. Therefore, radio astronomic observations can be simultaneously performed in 22 GHz, 43 GHz, 86 GHz, and 129 GHz bands, and phase variations of electromagnetic waves in the bands can be compensated for.