Automated Calibration of Modulated Frequency Synthesizers

In recent years, there has been considerable interest in highly integrated, low power, portable wireless devices. There are three primary areas to be addressed when higher performance and lower power are desired. The first area is the device technology. Scaling of devices has realized steady improvements for many years. The second area is improved circuit design techniques. The final area is at the architectural level. This monograph focuses on the problem of low power GFSK/GMSK modulation and presents an architectural approach for improved performance. The new architecture is a modulated S-D fractional-N frequency synthesizer. The key innovation is an automatic calibration technique, which operates in the background. The availability of the calibration circuit makes high data rate, low power modulation possible.