A New CMOS BPSK Modulator with Optimal Transaction Bandwidth Control

A new BPSK modulator for Bluetooth applications is presented. The proposed modulator minimizes the bandwidth of the modulated carrier by minimizing the degree of sharpness of the transactions of modulated carrier. To avoid the drawbacks of large silicon area requirement of passive spiral inductors and transformers, CMOS active transformers are developed from corresponding CMOS active inductors. They are utilized in the design of the 1.6 GHz quadrature oscillator to provide a high-quality sinusoidal output. To assess the performance of the proposed modulator, a 1.6 GHz BPSK modulator has been implemented in a TSMC-0.18mum 1.8V CMOS technology and analyzed using SpectreRF from Cadence Design Systems with BSIM3v3 device models and the simulation results are presented.