Outphasing modulation in a series circuit with Сhireix compensation in class EF2
The paper presents a model of the radio transmitter output stage for generating signals with high peak-to-average ratio waveform (AM, single-sideband modulation, QAM), based on a series outphasing modulation circuit with Chireix compensation and class EF2 power amplifiers (PAs). The property of the class EF2 PA to maintain high efficiency when complex load resistance varies over a wide range is shown. It allows to preserve high efficiency of amplitude modulation at 15 times power back-off. Due to a higher power output capability than in a Chireix outphasing circuit with class E PAs, the proposed circuit can be widely used in broadcasting (short wave AM and DRM) and communication (WCDMA and LTE) transmitters with different output power levels and frequency ranges.
Sivchek I.V. Outphasing modulation in a series circuit with Сhireix compensation in class EF2. St. Petersburg State Polytechnical University Journal. Computer Science. Telecommunications and Control Systems, 2018, Vol. 11, No. 1, Pp. 7–17. DOI: 10.18721/JCSTCS.11101