| 摘要 |
PURPOSE:To compensate a delay time characteristic without losing the transmission characteristic even for a large power band-pass filter by constituting a branching device and a band block filter with a distributed constant circuit element through a comparatively simple constitution. CONSTITUTION:A compensation circuit consists of a distributor BC formed by a lambdag/4 line (lambdag is a guide wavelength), a band-pass filter BPF of compensated band, and a band-stop filter BEF. The center frequency of the band-stop filter BEF is made equal to the center frequency f0 of the band-pass filter BPF of compensated band, the delay time characteristic of the band-stop filter BEF is formed as shown in Fig. A in response to the delay time characteristic of the band-pass filter BPF of compensated band, and the lambdag of the lambdag/4 line forming the branching device BC is made coincident with the wavelength of each center frequency f0 of the band-pass filter BPF of compensated band and the band-stop filter BEF of its odd number of times. The center frequency f0 of the transmission signal is stopped by the band-stop filter BEF, the frequency component other than the frequency f0 is reflected partly and absorbed partly in a pseudo load DA, the level distribution shown in Fig. B is obtained. |
