Design of a Dual-Band Doherty Power Amplifier Utilizing Simplified Phase Offset-Lines

Abstract

Abstract-This paper proposes a novel design methodology for dual-band Doherty power amplifier (DPA) with simplified offset-lines. The methodology is validated with the design and fabrication of a 10 W GaN based DPA for Global System for Mobile Communications (GSM) and Wideband Code Division Multiple Access (WCDMA) applications at 0.90 GHz and 2.14 GHz, respectively. In the measurement results, the DPA achieves a drain efficiency (DE) of 51.2% with an output power of 37.2 dBm at the 6.5 dB output power back-off (OBO) from the saturated output power at 0.90 GHz, and a DE of 39.9% with an output power of 37.4 dBm at the 6.5 dB OBO at 2.14 GHz. Linearity results using 20 MHz 16 QAM signal show an adjacent channel leakage ratio (ACLR) of −48 dBc and −43 dBc with the average output power of 37.2 dBm and 37 dBm at 0.90 GHz and 2.14 GHz, respectively.

A Survey on RF and Microwave Doherty Power Amplifier for Mobile Handset Applications

“…Precise alignment between the two paths at the baseband and isolation between the carrier and the peaking signals is crucial, which makes the implementation of the dual-input Doherty architecture challenging. Moreover, several limitations of digital DPA, like high oversampling, extensive pre-distortion requirements, and timing synchronization, restrict its application in multi-Gb b/s modulations [63,64] and limit the modulation speed. eliminates the signal splitting device and minimizes the wasted energy of the driving power into the peaking path.…”

Dual-band doherty power amplifier with improved reactance compensation

“…However, the majority of the published DPAs were designed to cater for single band but not multiband requirements. On the bright side, there have been several successful implementations of either dual-band PAs [20]- [22] or dual-band DPAs [23]- [25]. Zheng et al [23] used simplified phase offset-lines to show that the dual-band DPA design can achieve efficiencies of 51.2% and 39.9% at the 6.5 dB back-off point from saturation power at frequencies of 0.90 GHz and 2.14 GHz, respectively.…”

Design of dual‐band gan doherty power amplifier using a simplified structure

“…In addition, the design of power amplifiers for these advanced wireless communication schemes are facing new challenges including compact size and wide‐band/multiband operations. With advantages of high efficiency at back‐off power region and easy implementation, the Doherty power amplifier (DPA) is currently dominating the market of base station application for modern wireless communication, and it also attracts great interest from academia . However, most of the reported DPAs only work at a single narrow frequency band, which is not sufficient to address the design challenges of modern wireless communication schemes.…”

“…Meanwhile, the dual‐band operation of the DPA is highly desirable for modern communication systems due to its capability of reducing both the size and cost of the whole system. To realize the dual‐band function of the DPA, several new techniques have been reported recently . In , the dual‐band DPAs were designed based on the employment of dual‐band components .…”

“…To realize the dual‐band function of the DPA, several new techniques have been reported recently . In , the dual‐band DPAs were designed based on the employment of dual‐band components . In , a dual‐band DPA was designed using a parallel architecture.…”