A High Performance 20-42 GHz MMIC Frequency Multiplier with Low Input Drive Power and High Output Power

A 20-42GHz output frequency GaAs MMIC frequency doubler chip has been developed that requires low input drive power and produces high output power with high fundamental & harmonic suppression without any external filter. This developed chip has an integrated broadband single ended-in to differential-out active Balun with impedance inverter and a broadband waveform shaping circuit. The unique topology of developed Balun helps to produce high voltage swing at differential outputs at low input drive power with excellent amplitude and phase balance over the band. The differential outputs of active Balun are connected to balanced common source FETs and drive the balanced FETs in push-push configuration to generate second harmonics and reject fundamental and higher (odd) order harmonics. This creates a broadband frequency doubler with overlapping input and output frequencies, high conversion efficiency with good fundamental and higher odd harmonic rejection without any external Filter. The doubler work from -9 to +7 dBm. The output power of doubler is +17 to +18dBm in most of the band at Pin=+3dBm. Fundamental suppression is better than 50dBc to 34GHz and minimum 30dBc in the entire band. 3rd and 4th harmonic rejections are also better than 25dBc in most of the band. The phase noise of doubler is -137dBc/Hz at 100 kHz offset (fout=24GHz). The input return loss of doubler is better than 20dB in most of the band and output return loss varies from 10-15dB over the band. It works at Vd =4.5V, Id=100-225mA