Abstract: Disclosed is an electronic device comprising an inductive element configured to function in a communication mode as an antenna for picking up communication signals, and in a power conversion mode as an inductive element configured to be the energy storage inductor in a switching regulator used for conditioning the power available from an internal power source to power for powering the device, and a controllable switch for switching between said communication mode and said power conversion mode. The communications system further comprises a controllable switch for connecting said inductive element to either said receiver or said power conversion circuit. The controllable switch switches the system between the communication mode and the power conversion mode by means of unipolar or bipolar transistor switches or by mechanical switches or relays. The communication system may be used in an in-vivo medical device.

Abstract: Disclosed is an electronic device comprising an inductive element configured to function in a communication mode as an antenna for picking up communication signals, and in a power conversion mode as an inductive element configured to be the energy storage inductor in a switching regulator used for conditioning the power available from an internal power source to power for powering the device, and a controllable switch for switching between said communication mode and said power conversion mode. The communications system further comprises a controllable switch for connecting said inductive element to either said receiver or said power conversion circuit. The controllable switch switches the system between the communication mode and the power conversion mode by means of unipolar or bipolar transistor switches or by mechanical switches or relays. The communication system may be used in an in-vivo medical device.

Abstract: A polar loop transmitter circuit arrangement includes a circuit input, a circuit output and a controllable signal source. A modulator is coupled between the signal source and the output, whilst a first logarithmic amplifier is provided having its input coupled to the circuit input. A second logarithmic amplifier is also provided having its output coupled to the circuit output. An output of each logarithmic amplifier is coupled to a respective input of a comparator, and an output of the comparator is coupled to an input of the modulator. The logarithmic amplifiers can be successive detection logarithmic amplifiers, such amplifiers having an RF output which is amplitude limited and can be designed to have constant phase limited output.

Abstract: A polar loop transmitter circuit arrangement includes a circuit input, a circuit output, a controllable signal source, a modulator connected between the signal source and the output, a first amplifier having its input connected to the circuit input, a second amplifier having its input connected to the circuit output, and a comparator. Each amplifier preferably includes respective amplitude detector and signal modifier portions connected in series between their respective inputs and outputs. An output of each of the amplifiers is connected to a respective input of the comparator, and an output of the comparator is connected to a control input of the modulator. The amplifiers may each be characterized by transfer functions that are generally logarithmic. Each amplifier's signal modifier portion may further include an analog-to-digital converter, a digital signal modifier, and a digital-to-analog converter.

Abstract: A frequency modulation system is disclosed which includes a voltage-controlled oscillator (VCO) 43 and a phase detector 47 configured to receive an output signal from the VCO. The phase detector is arranged to output an error signal representing the phase difference between the signal from the VCO and a reference signal. The system also includes control means 62 arranged to monitor the error signal to derive an indication of the frequency deviation of the VCO, and, in accordance with this derivation, to maintain the frequency deviation of the VCO substantially constant.

Abstract: A frequency modulation system is disclosed which includes a voltage-controlled oscillator (VCO) 43 and a phase detector 47 configured to receive an output signal from the VCO. The phase detector is arranged to output an error signal representing the phase difference between the signal from the VCO and a reference signal. The system also includes control means 62 arranged to monitor the error signal to derive an indication of the frequency deviation of the VCO, and, in accordance with this derivation, to maintain the frequency deviation of the VCO substantially constant.

Abstract: A polar loop transmitter circuit arrangement comprises a circuit input, a circuit output, a controllable signal source, a modulator connected between the signal source and the circuit output, a first signal-amplitude-sensitive element having its input connected to the circuit input, a second signal-amplitude-sensitive element having its input connected to the circuit output, a comparator, and at least one controllable attenuator. An output of each of the signal-amplitude-sensitive elements is connected to a respective input of the comparator, and an output of the comparator is connected to a control input of the modulator. Another controllable attenuator may also be connected between the circuit output and an input of the second signal-amplitude-sensitive element. The signal-amplitude-sensitive elements may correspond to amplitude detectors in some embodiments of the technology, and to logarithmic amplifiers in other embodiments.

Abstract: A polar loop transmitter circuit arrangement includes a circuit input, a circuit output, a controllable signal source, a modulator connected between the signal source and the output, a first amplifier having its input connected to the circuit input, a second amplifier having its input connected to the circuit output, and a comparator. Each amplifier preferably includes respective amplitude detector and signal modifier portions connected in series between their respective inputs and outputs. An output of each of the amplifiers is connected to a respective input of the comparator, and an output of the comparator is connected to a control input of the modulator. The amplifiers may each be characterized by transfer functions that are generally logarithmic. Each amplifier's signal modifier portion may further include an analog-to-digital converter, a digital signal modifier, and a digital-to-analog converter.

Abstract: A polar loop transmitter circuit arrangement includes a circuit input, a circuit output and a controllable signal source. A modulator is coupled between the signal source and the output, whilst a first logarithmic amplifier is provided having its input coupled to the circuit input. A second logarithmic amplifier is also provided having its output coupled to the circuit output. An output of each logarithmic amplifier is coupled to a respective input of a comparator, and an output of the comparator is coupled to an input of the modulator. The logarithmic amplifiers can be successive detection logarithmic amplifiers, such amplifiers having an RF output which is amplitude limited and can be designed to have constant phase limited output.

Abstract: A transmission system receiver compares the received signal power in a relatively narrow frequency band with the received signal power in a relatively wide frequency band, which embraces the narrow frequency band, to obtain an indication of the "SINAD ratio" which refers to the signal plus noise plus distortion to noise plus distortion ratio. The receiver also includes an automatic control system for comparing the indication with a reference and for adjusting an attenuator in response to disparity between the indication and the reference in a sense to increase the SINAD ratio above a predetermined level, or to adjust the SINAD ratio to an optimum value.