Low-cost, active frequency-doubler MMIC in SMT package for 6-20GHz commercial applications

This paper describes the development of a SMT-packaged 620GHz frequency-doubler MMIC. The frequency-doubler is implemented in a 0.15um GaAs PHEMT process and low-cost SMT package. This MMIC employs a unique differential-pair active balun input stage with waveform-shaping circuit and active load. Balanced common-source FETs are used for 2nd-harmonic generation. The FET-drains are combined at output to achieve odd-order cancellation. This creates a broadband, low input-drive, high conversion efficiency frequency-doubler with decent fundamental & harmonic suppression. At optimum input power of -4dBm, it achieves 11dB conversion gain without amplification stage. Fundamental and 3rd-order suppressions are greater than 20dB across the frequency band. This work has demonstrated the capability to manufacture packaged frequency-doublers for cost-sensitive applications. It consumes 120mW (4V, 30mA) power.