Abstract: A high-frequency oscillator is provided for a frequency range of 1.6 to 3 GHz. An oscillator stage includes an oscillator transistor and a voltage-controlled resonator unit. A buffer stage is connected at an output of the oscillator stage. The resonator unit includes an open resonator in the form of an etched structure with a wavelength which is shorter than lambda/4 (where lambda is an oscillator length). The resonator unit includes a voltage-controlled variable-capacitance diode, and a resonator terminal is connected between the voltage-controlled variable-capacitance diode of the resonator unit and the oscillator transistor of the oscillator stage. The resonator is preferably an open microstrip resonator, and the stages are disposed in a standardized housing in SMD (surface mounted device) technology.

Abstract: A UHF-feedback oscillator for a frequency range of at least 300 MHz to 1000 MHz includes an amplifier stage, a voltage controlled tuning filter and a feedback quadripole. The feedback quadripole comprises a two- or three- loop helical waveguide resonator. Thus, the oscillator is easily adjustable to its oscillating condition within the very wideband frequency range of between 300 MHz and 1000 MHz and can be miniaturized in the simplest manner.