Controlled antenna tuner

An antenna tuner comprising:

• a. a transceiver;
• b. a dc filter 10 operatively connected to the transceiver for removing any RF signals, a voltage comparator 18 and an antenna unit 8 operatively connected to the dc filter output, said voltage comparator for comparing the dc output to a reference voltage and selectively outputting a transmit signal, and said antenna unit providing a power on/off signal;
• c. a control means 182 operatively connected to the transmit output terminal of the voltage comparator for receiving the transmit signal and selectively outputting a bias signal;
• d. a power bias and voltage regulator circuit 20 including a transistor switch 21 for controlling the voltage during transmit and receive, said transistor having an emitter connected to the power on/off signal of the antenna unit, a base connected to the bias signal of the control means, and a collector, first and second voltage regulators 23 & 25, said first voltage regulator 25 connected to the collector of the transistor switch for providing a first preselected voltage and said second voltage regulator 23 connected to the antenna unit for providing a second preselected voltage;
• e. a power amplifier 28 operatively connected to the first and second preselected voltages of the power bias and voltage regulator circuit for selectively turning on and off the power amplifier;
• f. a transmit switch 30 operatively connected to the transceiver and control means;
• g. an attenuator 43 and an RF detector 36 operatively connected between the transmit switch and power amplifier, said attenuator for adjusting the energy supplied to the power amplifier for transmit;
• said RF detector being operative for searching the transceiver output for RF signals and selectively outputting an RF present signal, a sample and hold circuit 38 connected to the RF detector for generating a fast attenuator time constant signal when no RF is detected after a preselected time and a reset signal, an attenuator driver 40 connected to the sample and hold fast attenuator time constant signal output and to the control means for providing a power selective signal to the attenuator 43 for selectively controlling the power output of the power amplifier, a ramp control circuit 22 connected to the sample and hold circuit reset terminal for resetting ramp control circuit to its original state in response to the reset signal output of the sample and hold circuit, said ramp control circuit operatively connected to the power amplifier for controlling the rate of power amplifier turn on commensurate to the ALC operation;
• h. a transmit/receive switch (32) operably connected to the control means, said T/R switch incuding a first switch 34 connected to the transceiver for bypassing the power amplifier during receive, and a second switch 31 connected to the output of the power amplifier, said second switch 31 coacting with the transmit 30 in response to the control means to selectively switch in the power amplifier during transmit;
• i. a low pass filter network 42 including a plurality of filters and a plurality of switches operably connected to the control means for selectively connecting the filters into the transmit/receive switch for channel frequency selection;
• j. a VSWR circuit 44 operatively coupled to the output of the low pass filter network, said VSWR circuit for sampling the reflected power and the forward power in a comparator and selectively outputting a signal indicating whether the VSWR exceeds a preselected ratio;
• k. an antenna coupler circuit 58 including a tuning means 83 operatively connected to the output of the low pass filter network, said tuning means having a plurality of inductors 102-120 and a plurality of switches connected to the control means for selectively connecting the inductors in series into the antenna coupler circuit in response to signals from the control means, a first plurality of shunt capacitors 86-100 and a first plurality of switches connected to the control means for selectively connecting the shunt capacitors into the antenna coupler circuit on the transceiver side of the plurality of inductors in response to signals from the control means, and a second plurality of shunt capacitors 122-128 and a second plurality of switches connected to the control means for selectively connecting the shunt capacitors into the antenna coupler circuit on the antenna side of the plurality of inductors in response to signals from the control means;
• l. a magnitude impedance bridge 50 operatively coupled to the antenna coupling circuit and control means for comparing the transmitter power and the antenna power for selectively outputting a signal to the control means indicative of an antenna impedance above or below a reference impedance;
• and
• m. a phase detector bridge 52 operatively coupled to the antenna coupler circuit and control means for comparing the transmitter power and antenna power for selectively outputting to the control means a signal indicating whether the antenna is inductive or capacitive;
• whereby said control means in response to the outputs of the magnitude impedance bridge and the phase detector bridge selectively outputs signals to the plurality of switches for the plurality of inductors, and first and second plurality of switches for the first and second plurality of shunt capacitors for selectively connecting inductors and shunt capacitors into the antenna coupling circuit until the antenna is tuned, and said control means indicates the tuning thereof to the transceiver.