Dynamic Power Supply Transmitters

Abstract

Learn how envelope tracking, polar modulation, and hybrid designs using these techniques really work. The first physically based and coherent book to bring together a complete overview of such circuit techniques, this is an invaluable resource for practicing engineers, researchers, and graduate students working on RF power amplifiers and transmitters. Create more succesful designs: • Step-by-step design guidelines and real-world case studies show you how to put these techniques into practice • A survey of various transistor technologies will help you to choose which type of transistor to use for best results • Details on testing and measurement of all aspects of these designs explain how to measure what the circuit is actually doing and how to interpret measurement results Earl McCune is a practicing engineer and Silicon Valley entrepreneur. A graduate of UC Berkeley, Stanford University, and UC Davis, he has over 35 years of postgraduate industry experience in wireless communications circuits and systems and more than 70 issued US patents. Now semi-retired, he has founded two successful start-up companies in addition to working in medium and very large corporations. He is also the author of Practical Digital Wireless Signals (Cambridge University Press).

Precompensation of Supply Dynamics of Dynamic Power Supply Transmitters Using a Linear Parameter-Varying Model

“…7. Shaping function that gives the relationship between the instanteneous input power P in , at RF in , and the DC supply voltage Vs required to obtain a constant joint transfer function [1] of 28.4 dB for all relevant input powers.…”

“…D URING the design of any Dynamic Power Supply (DPS) transmitter (see Fig. 1) including Envelope Tracking (ET), Direct Polar (DP) modulation and any hybrid combination involving both architectures [1], special care has to be taken on handling the relationship between the theoretical envelope signal (E in ) and the modulated supply voltage (E s ) that is actually applied to the DPS. This relation is theoretically well-defined, but exhibits non-idealities in practice [2].…”

Improving efficiency, linearity and linearisability of an asymmetric doherty power amplifier by modulating the peaking Amplifier's supply voltage

“…Conventional ET is limited to the L-mode region, where the output power depends predominately on the input power, see Fig. 2 [8]. In this region, a change of drain voltage will increase the efficiency without influencing output power or gain of the amplifier.…”

Supply Modulator Ripple in Envelope Tracking Systems - Effects and Countermeasures

“…Future generation communication systems will need to transfer data at much higher rates in comparison to existing systems, to accommodate the expected dramatic increase in mobile-cellular connectivity and wireless information exchange. To improve spectral efficiency, modulation schemes use signals with high peak-to-average power ratio (PAPR), leading to the substantial variation of the envelope magnitude of the modulated signal [1]. This dynamic variation in power distribution requires the conventional RFPA to operate under power back-off conditions, avoiding compression, which presents technical challenges in terms of achieving high linearity and back-off efficiency simultaneously [2].…”