This paper demonstrates the low voltage operation of a doubly balanced Gilbert mixer fabricated in a 0.8-m CMOS process and operating as both a down-converter and an upconverter. As a down-converter with an RF input of 1.9 GHz, the mixer has a single sideband noise figure as low as 7.8 dB and achieved down-conversion gain for supply voltages as low as 1.8 V. As an up-converter, the mixer demonstrates 10 dB of conversion gain at an RF frequency of 2.4 GHz with an applied local oscillator (LO) power of 07 dBm and LO-RF/LOIF isolation of at least 30 dB. Up-conversion gain was achieved over a 5-GHz bandwidth and at supply voltages as low as 1.5 V. The mixer presented demonstrates the lowest single side band noise figure for a CMOS doubly balanced down-converting mixer and the highest frequency of operation for a mixer fabricated in CMOS technology to date. Index Terms--- CMOS integrated circuits, frequency conversion, microwave measurement, microwave mixer, mixer noise, mixers, power dema...

An approach is presented for the analysis of the nonlinear behavior of analog integrated circuits. The approach is based on a variant of the Volterra series approach for frequencydomain analysis of weakly nonlinear circuits with one input port, such as amplifiers, and with more than one input port, such as analog mixers and multipliers. By coupling numerical results with symbolic results, both obtained with this method, insight into the nonlinear operation of analog integrated circuits can be gained. For accurate distortion computations, the accuracy of the transistor models is critical. A MOS transistor model is discussed that allows us to explain the measured fourth-order nonlinear behavior of a 1-GHz CMOS upconverter. Further, the method is illustrated with several examples, including the analysis of an operational amplifier up to its gain-bandwidth product. This example has also been verified experimentally. Index Terms---Analog integrated circuits, harmonic distortion, nonlinear ...

Since several years the research in the possibilities of CMOS technologies for RF applications is growning enormously. The trend towards deep sub-micron technologies allows the operation frequency of CMOS circuits above 1GHz, which opens the way to integrated CMOS RF circuits. Several research groups have developed high performance down-converters, low phase noise voltage controlled oscillators and dual modulus prescalers in standard CMOS technologies. The research has already demonstrated fully integrated receivers and VCO circuits with no external components, nor tuning or trimming. Further research on low noise amplifiers, up-converters, synthesizers and power amplifiers will hopefully result in CMOS RF circuits for fully integrated transceivers for telecommunication applications. 1. Introduction A few years ago the world of wireless communications and its applications started to grow rapidly. The driving force for this is the introduction of digital coding and digital s...