Low-power, high-accuracy, and fast-tuning integrated continuous-time 450-KHz bandpass filter

In this thesis, a low-power, high-accuracy, and fast-tuning monolithic continuous-time bandpass filter (BPF) is presented. The integrated BPF is intended to replace the bulky and expensive surface acoustic-wave (SAW) filter in many high-performance wireless applications such as Personal Communication System (PCS), Personal Digital Cellular (PDC), and Wideband Code-Division Multiple Access (WCDMA) handsets. With such consideration, the integrated filter in this thesis is designed for low power using a standard CMOS process. Beside the low-power design techniques presented in this thesis, a technique to enhance the performance of integrated filters by reducing excess phase is proposed. As well, the feature of constant-Q tuning for integrated continuous-time filters is also introduced. In conjunction with the design of a low-power 450kHz bandpass filter presented in this thesis, an embedded high-accuracy and high-speed automatic tuning scheme to compensate for process variations, temperature shifting, and component aging is also proposed. Extensive evaluation of the filter and the tuning scheme is carried out with analytical analyses and simulations at the transistor level. The filter and the tuning scheme is fabricated in 0.25-μm CMOS technology for verification and comparison between the simulated and experimental performances.