UHF oscillator tunable over wide frequency band - is suitable for frequency switched radar and has output impedance with negative resistance component

摘要

The UHF oscillator manually or mechanically tunable over a wide frequency band, normally tens of megahertz or several gigahertz. Change of frequency can be rapid and suitable for switched frequency radar. The oscillator is based on the use of a Gunn or avalanche diode or a unipolar or bipolar transistor. The diode or transistor circuit feeds the load via a series resonant tuning circuit and a four terminal network. The output impedance of the network is purely a negative resistance in the required frequency band and purely negative or positively reactive outside the band. A second such network may be connected between the tuning circuit and the load.