Hybrid Integrated Ku-Band VCO

A hybrid integrated Ku-band voltage controlled oscillator is described. The oscillator design is based upon a linear circuit model of the GaAs-MESFET NE71000. The oscillator circuit is subdivided into two chained twoports, an active twoport containing only the voltage controlled current source modelling the transconductance of the MESFET and a linear feedback twoport containing all the other circuit elements of the transistor as well as the oscillator circuit embedding the FET. Using this model we optimized the oscillator circuit within the whole tuning range. An output power of 12 dBm within a tuning bandwidth of 3 GHz was achieved. High Q-varactors were used in order to obtain good phase noise performance. A phase noise of ¿70 dBc/Hz at an offset of 10 kHz of the carrier has been measured.