Output Power Control in Class-E Power Amplifiers

Process, Voltage and Temperature Compensation Technique for Cascode Modulated PAs

“…The concept of a cascode modulated PA was introduced in [16] and [19]. The cascode modulation approach is an alternative technique of amplifying polar modulated signals to a traditional supply modulation scheme [17].…”

“…The detailed state-of-the-art class-E PA analysis and design equations can be found in [20], [21] The main feature of the cascode modulated class-E PA is the ability to control the output power by varying the voltage . The cascode voltage can be employed to control the average output power level [19] or it can be used to apply varying envelope signal in the case of a polar transmitter [16]. The output network of the cascode modulated PA in Fig.…”

A 1.8 GHz Power Amplifier Class-E with Good Average Power Added Efficiency

“…There have been several fully integrated implementations of class-E PAs in CMOS reported-see e.g., [5][6][7][8][9]. More recent communications systems are all using both amplitude and phase modulation to increase the data rate and spectral efficiency.…”

“…Many power control techniques [4][5][6][7][8][9] have been carried out before. For example, the conventional power control of a switch-mode PA is implemented by adjusting the supply voltage [11].…”

K-band CMOS power amplifier with adaptive bias for enhancement in back-off efficiency

“…Back-off efficiency of power amplifiers is highly emphasized in communication systems by the more-than-20 dB power variation due to modulation techniques [1] and the distance between device and base station [2]. Moreover, the peak efficiency of PAs typically corresponds to a output level beyond the output 1-dB gain compression power (OP 1dB ), and self interferences might contaminate the spectrum when PAs are operated in such a nonlinear region.…”