Abstract: High-frequency, low-power CMOS oscillators having electrically-tunable tank circuits are disclosed. Electrically-tunable inductors assure highly efficient oscillator operation and can be adjusted after manufacture to assure high yields of high-precision oscillator circuits.

Abstract: A transistor device for a microwave oscillating element having an FET transistor chip and a package encapsulating the chip therein. In order to avoid any affection of the external circuit to the input impedance of the transistor device and to make the phase rotation low at a frequency band higher than the X band, a conductor element is provided within the package to connect the drain electrode of the chip and a corresponding terminal of the package. The conductor element has an inductance to provide a sufficient high impedance at the intended frequency band. The conductor element is supported on an insulator plate fixedly mounted within the package.

Abstract: An automatic tuning circuit is provided for adjusting the frequency and phase of an oscillatory circuit in a power supply used for providing high frequency electrical energy to an electroacoustic converter. The oscillatory circuit includes an electrically variable inductance means in a feedback loop coupled between the output and an input of the oscillatory circuit and a switching device. The phase relationship of a signal indicative of the voltage across the switching device and a signal indicative of the state of the switching device and hence the current through the switching device is monitored. The inductance of the variable inductance means is adjusted responsive to the phase relationship of the signals indicative of voltage and current through the switching device for maintaining the two signals in phase during operation of the oscillatory circuit.

Abstract: The tuning system for a high frequency receiver, particularly an AM receiver for vehicles, comprises a tunable input resonance circuit having a variable inductance formed by the signal winding of a controllable inductor. The control winding of the inductor is supplied with a control current. The control winding is simultaneously used as the frequency determinative element of an auxiliary oscillator. A frequency control loop is used to adjust the oscillating frequency of the auxiliary oscillator by adjustment of the control current. The tuning system allows a selective coupling between the tuned antenna input circuit and the rf front end of the receiver.