High frequency antenna tuning device

Claim 1

A high frequency antenna tuning device, in which the antenna has a first end which is connected to reference earth and a second end connected to the output of the device, the point of the antenna close to the first end being connected to the power output of a transmitter, which periodically supplies power signals transmitted by the attenna at high frequencies predetermined by an interface, the tuning device having for each predetermined frequency a tuning capacitor connected to the reference earth and to one terminal of a switch, whereof another terminal of the switch is connected to said output of the device, wherein said tuning device further comprises means for controlling the switches respectively connected to the control inputs of said switches and to frequency identification outputs of the transmitter, each identification output corresponding to one of the predetermined frequencies and supplying during each period corresponding to the transmission of power signals at said frequency, an identification signal indicating that the tranmitter is supplying on its power output a power signal at said frequency, means for detecting the frequencies of the signals transmitted by the antenna, one output of said detection means being connected to the control means for supplying a detection signal for preventing any switching of any random one of the switches throughout the duration of each period of transmitting power signals at each predetermined frequency.