Active Mixer Eases 3G Basestation Design

Coming to the aid of 3G basestation makers, the LT5521 linear active mixer promises to streamline design by resolving the high local oscillator (LO) drive level, poor LO suppression, and low conversion gain issues common to passive topologies. The device employs a differential input and output architecture that supports linearity over a operating frequency range from 10 MHz to 3.7 GHz. Working as a transmit (up-converting) mixer, input third-order intercept is +24.2 dBm at 1,950 MHz, and the noise figure measures 12.5 dB. Compared to passive mixers, which require a high LO drive level up to +17 dBm, the LT5521 needs just -5 dBm. Available in a 16-pin, 4 mm x 4 mm surface-mount QFP, price is $4.95 each/1,000. LINEAR TECHNOLOGY CORP., Milpitas, CA. (800) 454-6327.