Abstract: An antenna driving circuit for connecting an antenna to two transmitters is disclosed. The antenna driving circuit includes a hybrid combiner that has two isolated inputs. The hybrid is configured so that when a first signal is input to the first input, substantially one half of the energy of the first signal is output at the first output and the first signal is phase shifted by about -90 degrees at the first output. Substantially one half of the energy of the first signal is output at the second output and the first signal is phase shifted by about 0 degrees at the second output. When a second signal is input to the second input, substantially one half of the energy of the second signal is output at the second output and the second signal is phase shifted by about -90 degrees at the second output. Substantially one half of the energy of the second signal is output at the first output and the second signal is phase shifted by about 0 degrees at the first output.

Abstract: An automatic antenna coupler is disclosed. The antenna coupler automatically matches the output impedance of a 50-ohm transmitter to the input impedance of a non-broad-band antenna, such as a whip, dipole or long wire. The resulting increase in transmit coupling efficiency provides greater radiative power than that available from an unmatched antenna.