Compact GaInP/GaAs HBT Gilbert Mixers With On-Chip Active LO Balun

A Gilbert micromixer is demonstrated in this paper using GalnP/GaAs HBT technology. The RF, LO, and IF ports of the micromixer are all single-ended using the on-chip active LO balun. The port-to-port isolation has its best performance when the LO signal is balanced. The stand-along micromixer is suitable for hybrid RF system applications. The fully matched high linearity micromixer has the conversion gain of 12 dB, IP_IdB of-9 dBm, IIP₃ of 1 dBm when input IF=300 MHz, LO=3.5 GHz and output RF=3.8 GHz.