Antenna control unit

PURPOSE:To enable to control the antenna tuning with digital signal, by controlling the variable reactance of the antenna circuit forming the transmission conductor line with bending with the signal in D/A converting the reception frequency set code. CONSTITUTION:The antenna circuit 1 consists of the a pair of antenna elements 1a, 1b of distributed inductance bending the transmission conductor line, variable reactance circuits 4a, 4b having the varactor diodes 5a, 5b, and impedance adjusting capacitor connected between the power feeding terminals 3a, 3b. The tuning of the circuit 1 is made by latching the reception frequency set code fed to the terminal 9 of the control circuit 8 with the latch circuit 10 and by applying the analog signal in D/A converting 11 the output to the diodes 5a, 5b. Accordingly, the tuning of the circuit 1 is controlled with digital code and by installing the circuit 8 apart from the antenna, the remote control for antenna tuning can be made possible.