A 200-MHz sub-mA RF front end for wireless hearing aid applications

A hearing-aid system with RF connection between both ear-pieces is described and its transceiver is introduced. A suitable 200-MHz RF front end has been implemented in a 0.8-/spl mu/m BiCMOS technology. Low power consumption and area constraint were key requirements. The chip comprises a low noise amplifier (LNA), a single balanced mixer, a varactor tuned LC local oscillator with buffer and a 16/17 dual-modulus prescaler. The LNA has a measured gain of 17.5 dB at 200 MHz. The conversion g/sub m/ of the mixer is 1.88 mS. The overall voltage gain and noise figure are 26 dB and 5.2 dB, respectively. The voltage-controlled oscillator's (VCO's) phase noise is -104.7 dBc/Hz at an offset of 24 kHz.