High frequency duplexer particularly for television transmitters - replaces cavity type resonaters at high power levels

摘要

The duplexer for high frequencies and for high power systems is one where a flat response is required over the specified pass - bands. It is intended to replace cavity, wave - guide types, resulting in low voltages in the system without loss of power. The duplexer consists of two inputs feeding a 3db directional coupling having a characteristic impedance. One of the coupling elements is a travelling wave resonator and the other a dephasing circuit. The length of the coupling is roughly equal to C/(F1 - F2) where F1 is the mean channel frequency and F2 the parasitic frequency.