摘要 |
An integral phase shifting network (215,216,217) of a transmitter filter (104) provides a means to reduce the size and increase the efficiency of an antenna coupling network. The network to shift the phase of the transmitter filter (104) is printed by depositing conductive material directly on a ceramic block (230) using low-loss circuit elements and can be tuned easily by removing conductive material if required in certain applications. By utilizing an integral phase shifting network (215,216,217), either transmit filter (104) or receive filter (112) having a highly reactive and capacitive out-of-band impedance in the receive or transmit band, respectively, can be connected to a common antenna port without external transmission lines. |