| 摘要 |
PURPOSE:To reduce the influences of unnecessary waves without reducing noise characteristics by cooling a band-pass filter inserted into a signal input circuit down to an extremely low temperature. CONSTITUTION:A signal inputted to a signal input waveguide 1 is lead into a waveguide in a vacuum case 7 through a heat insulating choke waveguide flange 51 and amplified by the band-pass filter 11 and low noise amplifier body 3 which are cooled down to an extremely low temperature by a cooler 6. The amplified signal is outputted to a signal output waveguide 4 through a heat insulating choke waveguide flange 52. |
