10-GHz Highly Symmetrical Sub-Harmonic Gilbert Mixer Using GaInP/GaAs HBT Technology

A 10-GHz sub-harmonic Gilbert mixer is demonstrated using GaInP/GaAs hetero-junction bipolar transistor technology. The local oscillator (LO) signal time-delay path in the sub-harmonic LO stage is compensated using the fully symmetrical stacked-LO doubler; therefore, the balance of the sub-harmonic LO stage, the radio frequency to intermediate frequency isolation, and IIP
₂
are improved. The demonstrated 10-GHz sub-harmonic mixer achieves 10 dB conversion gain, IP
_1dB
of -12 dBm, IIP
₃
of 2 dBm and IIP
₂
of 33 dBm