| 摘要 |
PURPOSE:To facilitate the control work and at the same time to simplify the circuit constitution, using a dielectric filter. CONSTITUTION:Input terminals 11 and 12 are connected to the 1st and 2nd UHF antennas respectively and supply the signals of adjacent channels. An input terminal 13 supplies the signals other than those mentioned above, a dielectric filter 14 is provided together with a wide band LPF 15. The filter 14 contains a ceramic capacitor 14a, a ceramic trimmer capacitor 14b, a capacitor 14c and a dielectic resonator 14d. Then 4 trimmer capacitors 14b perform the control to obtain the desired characteristics. The filter 14 can be controlled just through 4 points of the capactiors 14b, and no effect is given to an inductance 15a of the LPF 15. This eliminates the control of the LPF 15. |
