Research And Implementation Of Low Voltage Configurable Channel Select Filter In Multi-mode Multi-frequency Receiver

With the rapid development of wireless technology and 3G product. The research of multi-mode portable terminals become the hotpot. With the development of IC progress technology,the IC voltage is becoming lower,so the low voltage design is very important.This paper discuss a channel setect filter, which can satisfy GSM, RFID,TD-SCDMA, WLAN a/b/g. This filter is implemented in 0.13μm CMOS at 1.1 V power supply voltage,the result of the reaserch is showing below:1. Based on the theory of Biquad filter,design a four order Butterworth filter use multiple feedback architecture with 3bit control terminal. in order to make the channel select filter to obtaina good adjacent channel rejection (ACR), use three four order Butterworth filter cells connect together, reduce the complexity of filter design, also reduce the requirement of the operation amplifier's GBW.2. Design a two stage operation amplifier with miler compensation the first stage use folder cascade architecture and the second stage is common source amplifer architecture.The operation amplifier's DC gain is 67dB and the phase margin is 66degree. The GBW is 220MHz.it can both satisfy the specification of the filter and reduce the power dissipation.3. Use a resistance reuse technology in the switch resistance array, and reduce the area of the channel select filter chip.4. Analysis the trade off of the filter's first stage gain contribute to the filter system's noise and linearity. guarantee the linearity of the filter then add a preamplifier stage with 12dB gain to reduce the filter's noise figure.5. The chip implemented in 0.13μm CMOS 1P8M technology,the core area of both I,Q channel select filter is 1.44 mm2..established circuit testbench and accomplished the test, test results show that the power dissipation is 14.3mW for one channel,the IIP3≥-5dBm.The filter's cutoff frequency can configured from 250kHz to 12MHz.