RF down-converting mixer targets mission critical apps

The LTC5551 offers a high linearity of 36dBm IIP3 and a low 9.7dB noise figure. Unlike passive mixers which typically have 7 to 9dB of conversion loss, the device boasts 2.4dB of conversion gain. It also has broad rf frequency range capability, operating from 300MHz to 3.5GHz. An integrated LO buffer requiring only 0dBm drive level is said to minimise external circuitry, while the elimination of a high power LO signal in the users' receiver reduces a potential source of undesirable radiation, thus simplifying filtering and rf shielding requirements. Both the rf and LO inputs have integrated balun transformers, further reducing cost and external components while simplifying the design task. The mixer is powered from a single 3.3V supply with current consumption of 204mA. If needed, the mixer also has a low power mode controlled via the ISEL pin. In this mode, current consumption drops by 30% to 142mA, trading off the IIP3 slightly to +29.3dBm. The LTC5551 is suitable for a number of mission critical, high performance applications - including multi-carrier GSM, 4G LTE and LTE-Advanced multimode basestations, point to point backhauls, military communications, wireless repeaters, public safety radios, VHF, UHF, radar and avionics.