A novel uniplanar 44 GHz MMIC subharmonic mixer using CPW series stubs

The design of a subharmonically pumped (SHP), monolithic microwave integrated circuit (MMIC) mixer for Satcom applications is described. The mixer uses an anti-parallel diode pair to achieve frequency translation by mixing the IF signal with the second harmonic of the fundamental local oscillator (LO) pump. The circuit was fabricated using OMMIC´s ED02AH foundry process and contains two pairs of 0.18 μm PHEMT based diodes, each, having two 15-μm cathode fingers. The measured conversion loss is 8 dB for an RF output signal of 44.51 GHz and the RF port return loss is better than 13 dB over the RF frequency range (43.5 to 45.5 GHz). The 2*f_LO suppression is better than 17 dB over the RF range of 43.5 to 45.5 GHz.