| 摘要 |
PURPOSE:To separate a microwave circuit and an antenna and to prevent the radiation pattern of the antenna from being disordered by constituting the microwave circuit on the reverse surface across the earth conductor of the radiation conductor of the antenna. CONSTITUTION:An incident high-frequency signal is inputted to a low noise amplifier 30 through the microstrip line composed of a coupling hole 5, the earth conductor 2, and a strip conductor 6, and amplified in a small noise state. The amplified high-frequency signal is inputted to a frequency converter 31 through the microstrip line, passed through a band-pass filter 20a, and inputted to a semiconductor element 8. A local oscillation signal from an input terminal 11, on the other hand, passes through the filter 20a and excites a semiconductor element 8 and is mixed with the high-frequency signal to generate an intermediate-frequency signal. The intermediate-frequency signal passes through a band-stopping filter 21 and is outputted from an output terminal 9. Neither the local oscillation signal nor the intermediate-frequency signal does not leak out to the filter 20a and neither the high-frequency signal nor the intermediate- frequency signal leaks out to the filter 20b; and none of the passing intermediate-frequency signal leaks out to the filter 21. |
