Abstract: A high frequency generator including a frequency generator and a multiplier, the multiplier including a diode, which multiplies the output frequency of the frequency generator, and shuts off or reduces an output by suspending or suppressing the multiplying operation through the control of a bias voltage applied to the diode used in the multiplier. The system for cutting off the output by controlling the multiplier is very effective for simplifying the circuit structure and reliably turning off the output.

Abstract: A frequency conversion unit comprising a local oscillator, first and second mixers, first and second hybrid circuits. The mixers receive, via the first hybrid circuit, local oscillation outputs from the local oscillator, and the second hybrid circuit receives outputs from the first and second mixers, producing a frequency conversion output signal therefrom. Intermediate frequency signals used in the first and second mixers are .pi. radians out of phase with each other. The first hybrid circuit produces outputs for the first and second mixers having a predetermined phase difference of .phi..sub.1 therebetween. The second hybrid circuit receives outputs from the first and second mixers and combines them after making a phase difference of (.pi.-.phi..sub.1) therebetween.

Abstract: A temperature compensating voltage generator circuit for compensating temperature characteristics of an electric circuit whose electrical characteristic varies in accordance with the change of the ambient temperature and whose electrical characteristic can be changed or controlled by a control voltage. The temperature compensating voltage generator circuit comprising a plurality of temperature sensitive resistor circuits, a plurality of diode circuits and one or more resistor circuits. A temperature compensating voltage from the temperature compensating voltage generator circuit being independently adjustable at each predetermined temperature.