A Tradeoff Design of Broadband Power Amplifier in Doherty Configuration Utilizing a Novel Coupled-Line Coupler

Abstract

Abstract-A broadband power amplifier designed and implemented in Doherty configuration is illustrated in this paper. Both input and output networks adopt the broadband matching topology. Additionally a compensation network, consisting of a series transmission line shunted with a capacitance, is set behind the peak amplifier to avoid in-band power leakage in the low-power section while at the cost of peak output power in partial band. A novel coupler is designed as an uneven power-divided splitter and experimentally validated for a broadband power amplifier module. A tradeoff of bandwidth, efficiency and output power is fulfilled through parameters select and postproduction tuning. According to the measured results, the proposed broadband Doherty power amplifier achieves an average saturated output power of 42 dBm, an average gain of 10.6 dB, an average peak and 6 dB back-off efficiency of 48.4% and 32.8%, respectively, and a fractional bandwidth of 51.4%, from 1.3 GHz to 2.2 GHz. The adjacent channel power ratio is better than −40 dBc when the amplifier is driven with 10-MHz QPSK signal, thus exhibiting a high linearity performance.

A trade-off design of microstrip broadband power amplifier for UHF applications

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Design of L-S band broadband power amplifier using microstip lines

“…On the other hand, the cellular mobile communication has reached tremendous advances in terms of technology and innovation as well as commercial accomplishment [9]. However, with the explosive proliferation of the RF and wireless communication standards, driven mostly by the growing demands to transmit an increasing amount of data, besides the growing need of rapid transport of signals in the next generation communication systems as well as the wider signal channels requirement, will lead in a deeply interest in broadband power amplifiers (BPAs) [10][11][12][13][14]. Such devices can supersede multi narrowband and 5401 single channel PAs, and inherently reduce the hardware research and develop fee due to the incompatibility of the new and previous telecommunication standards.…”

1.25 GHz – 3.3 GHz broadband solid state power amplifier for L and S bands applications

“…On other hand, the PA design requires an accurate active device-mostly a Radio Frequency Transistor -, stability in operation, impedance matching technique that depends on the operating frequency band, and a simple configuration for practical realization purpose. The active device bias conditions-that are commonly different for efficiency or linearity improvementdepend on the active device technology and the operating class of the PA [17][18].…”