A 18-45 GHz double-balanced mixer with integrated LO amplifier and unique suspended broadside-coupled balun

An ultra wide band double-balanced mixer with integrated LO buffer amplifier has been developed using 0.15u depletion mode PHEMT technology. The mixer employs a unique broadside-coupled balun for superior 18-45 GHz bandwidth and overcomes many of the disadvantages of edge coupled transmission lines in microstrip or stripline. The mixer utilizes GaAs HEMT S-D diode mixing and integrates LO power amplifier to ease the drive requirements typically associated with this type of mixing. The LO amplifier has a distributed input stage and sequential traditional common source FETs for efficient power amplification. The LO can also be sub-harmonically pumped for 2/spl times/ frequency multiplication as well as fundamentally driven. The result is a mixer capable of -10 dB conversion gain for up or down mixing across many commercial frequency bands for 18-45 GHz. LO power requires only 0 dBm.