High performance monolithic frequency doubler

Using 0.5?m GaAs MESFET technology, we have implemented a 7.5 to 15GHz monolithic frequency doubler which has a conversion gain of 2dB and a fundamnental signal suppression of 20dB for a 5dBm@7.5GHz input signal. A design criteria established by the authors, that leads to the calculation of the active device termination to optimise the output power (Pout) - conversion gain (Gconv) trade-off was used. To improve the simulations accuracy a non-linear model for the MESFET based on a modification of Tajima model was derived. The measured performances of the circuit demonstrates an excellent agreement with the linear and non-linear simulations and confi.ms the design approach.