A multi-band RF front-end receiver for Bluetooth, WCDMA, and GPS applications

A low intermediate-frequency (IF) multi-band receiver system adaptable in Bluetooth, wideband code division multiple access (WCDMA), and global position system (GPS) is proposed in this work. This receiver system includes three low-noise amplifiers (LNAs), I and Q mixers, and a multi-phase range-programmable voltage-controlled oscillator (VCO). Each LNA embedded with switches to have a gain approximately ranging from -90dB to 16dB is designed to minimize power dissipation and the intensity of unnecessary signals, and to increase in isolation. The multi-phase range-programmable VCO consists of a phase-setting unit and two range-programmable VCOs where the range-programmable VCO controls the number of its paralleled inverter rings in use to generate multi-band signals. Compared to the conventional dual-band and multi-band receivers, the proposed receiver uses the multi-phase range-programmable VCO to minimize cost of area and power dissipation. The proposed multi-band front-end receiver is implemented by TSMC IP6M 0.18/spl mu/m CMOS technology with a die size of 2.4/spl times/2.4mm/sup 2/. At a supply voltage of 1.8V, the gains of the three frequency bands of Bluetooth, WCDMA, and GPS could reach at least 24dB and more, noise figures at below 5dB, and IF frequencies consistently at 2MHz. Therefore, our front-end receiver architecture can be utilized at various integrated multi-band receiver systems with low hardware cost, low power dissipation and fairly good receiving performances.