The HMC521 devices are compact I/Q MMIC mixers that are available in a chip (HMC521) or a leadless Pb-free RoHS compliant SMT package (HMC521LC4), both of which can be used as either an IRM or a single sideband (SSB) upconverter. The mixers utilize two standard Hittite double-balanced mixer cells and a 90° hybrid fabricated in a GaAs metal semiconductor field effect transistor (MESFET) process. A low frequency quadrature hybrid was used to produce a 100 MHz USB IF output. These products are much smaller alternatives to hybrid style IRMs and SSB upconverter assemblies. All data shown for the HMC521 is taken with the chip mounted in a 50 Ω test fixture and includes the effects of 1 mil diameter × 20 mil length bond wires on each port. The HMC521LC4 eliminates the need for wire bonding allowing use of surface mount manufacturing techniques.ApplicationsPoint-to-pointPoint-to-multipoint radioMilitary radar