Switched capacitor based ring modulator using differential voltage current conveyor

This paper presents a switched capacitor based ring modulator using differential voltage current conveyor. It has the advantages of excellent frequency response with wide bandwidth, low voltage operation, very low total harmonic distortion, high speed and low power. It can be directly implemented using MOS transistors and the circuit can be easily fabricated. It requires only small number of passive components. This topology of modulator gives high frequency capability with low power consumption. The proposed design is realized in 750 nanometer technology CMOS process. The 3dB (decibel) frequency of the modulator is in the range of 1 Gigahertz. The proposed circuit substitutes an operational amplifier in the conventional design with the differential voltage current conveyor (DVCC) for the implementation. The circuit uses a single clock signal which sets and resets the DVCC and thus avoids the inter-modulation distortion to a higher degree of accuracy. Simulation results using TSPICE are presented. The frequency response and time domain results confirm the performance of the proposed circuit.