volume | PIER Journals

Abstract

This study proposes an extended design methodology for sequential load-modulated balanced amplifiers (SLMBAs), centered on regulating the impedance characteristics of balanced amplifiers (BAs) through continuous F^-1 class control amplifiers (CA). By expanding the load operating range of CAs at the second harmonic, the flexibility of high-efficiency designs is effectively enhanced. Theoretical analysis demonstrates that this load modulation mechanism overcomes the structural limitations of conventional LMBA, enabling high-efficiency power amplification across a wide frequency range and under conditions of large output power back-off (OPBO). Based on this architecture, an SLMBA prototype operating from 2.0 to 3.7 GHz was developed. Test results indicate that in saturated and 8 dB OPBO conditions, the drain efficiency (DE) reached 55.2%-68.7% and 46.8%-59.0%, respectively. When fed with an LTE signal featuring a 100 MHz bandwidth and 8 dB PAPR, the average DE across the entire bandwidth ranged from 49.2% to 58.3%, with an adjacent channel leakage power ratio (ACPR) exceeding -35 dBc.

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Mr. Jiadong Yu

Professor Jingchang Nan

Dr. Heyang Sun