SINGLE CHIP CMOS TRANSMITTER/RECEIVER AND VCO-MIXER STRUCTURE

摘要

A single chip RFcommunication systemand method and aVCO-mixer (130) structureare provided. The RFcommunication systemin accordance with thepresent invention includesa transmitter (1100) and areceiver (100), an antennafor receiving transmittingRF signals, a PLL (130)for generating multi-phaseclock signals having afrequency different froma carrier frequency inresponse to the multi-phaseclock signals and areference signal havingthe carrier frequency,a demodulation-mixingunit (140) for mixingthe received signal withthe multi-phase clocksignals having a frequencydifferent from the carrierfrequency to output the RFsignals having a frequency reduced by the carrier frequency and an A/Dconverting unit (160) for converting the RF signals from themixing unit into digital signals. The VCO (130) in accordance with the presentinvention includes a plurality of differential delay andthe mixer includes a differential amplifying circuit (1200A) and combiningcircuit (1200B). The differential amplifying circuit (1200A)of the multi-phase mixer includes two load resistors (R2, R1) coupled to twodifferential amplifiers (1200A1, 1200A2) respectively.The combining circuit (1200B) includes bias transistors (1232, 1234), firstand second combining circuits coupled to the bias transistors,respectively and a current source coupled to the first and second combiningunits.