| 摘要 |
<p>PURPOSE:To eliminate unnecessary radiation by housing an RF amplifier to amplify a reception signal, the detecting circuit of this output, a band pass filter, which extracts only the signal of a prescribed band to be received, in a metallic enclosure, for which a horn antenna is provided, and leadingout the detecting output of the detecting circuit. CONSTITUTION:An RF amplifier 13, a band pass filter 14 and a detecting circuit 15 are housed in a metallic enclosure 12, for which a horn antenna 11 is provided. The reception signal of the horn antenna 11 is suitably amplified by the RF amplifier 13, for which the low noise amplification positive element of a gallium arsenide electric field effect transistor is used, and given to the band pass filter 14. Only the signal of the prescribed band to be received is extracted and given to the detecting circuit 15, for which a gallium arsenide Schottky barrier type diode is used. Then, an AF signal is led out to an output terminal 16 as the detecting output. Thus, the unnecessary radiation of a local oscillating signal is eliminated.</p> |
