Ultra high frequency 100mhz power controller for RFPA power supply

In recent years, there has been a rapid and wide spread of non-traditional communication and computing platforms, especially mobile and portable communication and computing devices. As applications become increasingly sophisticated and processing power increases, the most serious limitation on these devices is the available battery life. Mobile communication has become a backbone in the field of global communication [1]. As the popularity and functionality increases it becomes necessary for the manufacturers and servicer's to provide reliable and efficient operation especially for the battery life. Radio Frequency Power Amplifier (RFPA) is the major power consumer in a transceiver system, therefore low-cost technique that can boost PA efficiency while maintaining high PA linearity is a vital for future wide band transceivers. Switch-Mode DC-DC power converters provide one of the most efficient method to regulate analog and digital supplies for battery powered RF transceivers. In reality hanheld devices typically require a different approach, not only due to their size, weight and cost but also due to the complex circuitry.;RF power amplifiers used in CDMA/WCDMA cellular standards have been traditionally powered directly from the battery. This makes system implementation easy but the requirement for linear power amplifiers in such standards have intrinsic inefficiencies throughout the transmit power spectrum.;Cellular standards have been evolving with transmission speeds that started from 14.4 kbps in CDMA-1 to 2 Mbps in CDMA200/WCDMA. Apart from this, cellular providers have increased the services bundled with the 3G phones in order to increase the average revenue per subscriber. At the same time, the talk time and battery life is expected to be improved with the same or slightly higher capacity batteries. This makes system design challenging. System designers have to be very cautious and perform a power survey of each and every component on the phone board. The RF Power Amplifier (RFPA) powered directly from the battery is a major concern from the power budget perspective.;The modulation schemes, which are used in CDMA and WCDMA, result in an amplitude-modulated signal that exhibits a non-constant amplitude envelope. In order to preserve signal integrity and further spectral re-growth, a linear power amplifier is necessary. However, power efficiency is traded off because power amplifiers operate efficiently when operated in gain compression. To meet the required linearity, the operating transmit power is backed off from the power amplifier's compression point that causes an overall reduction in efficiency. When the handset is operating in transmit mode, the RF power section consumes up to 65% of the overall power budget as a result of the PA's intrinsic inefficiencies.;In this research, an ultra-high frequency dynamically adaptive power supply targeted for radio frequency PA's is conceived, designed with AMI 0.5um CMOS technology. Whole controller has been divided three parts to implement high speed tracking of dynamic input. One-cycle control method, is used to integrate diode voltage in one-cycle and forces it to be exactly equal to the reference value [1]. Voltage mode regulation is combined with type 3 compensation to realize stable system modulation. Novel designs of high-speed voltage comparator and operational amplifier along with a less power driver circuit is introduced for getting high efficiency and speed. The designed power supply controller has a tracking bandwidth of 5MHz and a switching frequency of 100MHz.