| 摘要 |
PURPOSE:To obtain enough back-off of a signal and to reduce an undesired signal due to a higher harmonic wave component by providing a micro-wave and micro-wave input converting device, which uses a local frequency in a receiver side, and an intermediate frequency and micro-wave input converting device to use the local frequency in a transmitter side. CONSTITUTION:A transmitter 1 and a receiver 2 respectively have local frequencies f1l and f2l. A micro-wave and micro-wave input converting device 16 of a testing device 5 receives an output signal to have a frequency f1 from the transmitter 1 and the signal of the local frequency f2l from the receiver 2 and the signals are converted to a signal to have a frequency (f2l-f1) corresponding to an intermediate frequency level and selected by a low-pass filter 17. An intermediate frequency and microwave input converting device 18 receives a signal to have the frequency (f2l-f1) corresponding to the intermediate frequency level and the signal of the local frequency f1l from the transmitter 1 and converts these signals to a signal which has a micro-wave frequency f2. Since the level of a local frequency signal is made higher in comparison with the level of the signal to have the frequency f1, the back-off can be widely obtained. Then, when the frequency (f2l-f1) or f2 is extracted, the influence of a high frequency component is hardly sustained. |
