Extremely low power consumption GaAs MMIC LO drain injection mixer with negative feedback for L-band applications

Abstract

We have developed a LO drain injection MMIC mixer with negative feedback for L-band applications, showing extremely good intermodulation (IM) characteristics with a zero DC drain bias. The basic idea for the improvement of IM properties in this mixer is similar to that of an amplifier in which the distortion of GaAs FET is cancelled out of phase with negative feedback at the expense of associated gain. The fabricated mixer consumes basically zero static power, showing a conversion gain of 0.33 dB at a LO power of 10 dBm. The measured 3rd-order intercept point improves as the LO power increases. More than 5 dB improvements in the input IP3 over the entire LO power range have been observed in comparison with the conventional dual-gate FET mixer using the same kind of FET's. The fabricated chip size is 1.64 mm x 0.95 mm.