A 170 MHz RF front-end for ERMES pager applications

A 170 MHz RF front-end for ERMES pager applications has been implemented in a 1.2 μm BiCMOS technology. The chip comprises a low noise amplifier with AGC, a double balanced mixer, a varactor tuned LC local oscillator, and an IF strip containing an AGC amplifier and a double balanced mixer with integrated active output filter. The LNA has a measured gain of 22.3 dB at 170 MHz with a usable AGC range of approximately 20 dB while the conversion transconductance of the mixer is 130 μS. This front-end is suitable for direct conversion and superheterodyne pager receivers, and its noise figure is 6.2 dB. Low power operation has been achieved with the front-end drawing 230 μA at 3 V, which is compatible with the intended application in wrist-watch style pagers