A Ruggedness Improved Mobile Radio Frequency Power Amplifier Module with Dynamic Impedance Correction by Software Defined Atomization

Abstract

A ruggedness improved multi-band radio frequency (RF) power amplifier (PA) module applicable to mobile handsets, which are required to survive against a serious load impedance change under extreme power and bias conditions, is presented. In this method, the load impedance of PA is adaptively adjusted with a digitally controlled impedance corrector to keep the PA safe by performing a load mismatch detection. The impedance mismatch detector, impedance corrector, and other RF switches were all integrated into a single integrated circuit (IC) using silicon on insulator (SOI) complementary metal oxide semiconductor (CMOS). For the verification purpose, a 2-stage hetero junction bipolar transistor (HBT) PA module adopting this method was fabricated. At a frequency of 1915 MHz, a collector bias voltage of 4.2 V, and over a wider range of load impedance variation between a VSWR of 1 and a VSWR of 5.5, it did not fail. When this technique was not applied with a voltage standing wave ratio (VSWR) range of 1 to 4, it resulted in an acceptable RF performance degradation of 1% power added efficiency (PAE) in envelope tracking (ET) mode. Moreover, it survived at a bias voltage 1V larger than when the technique was not applied for the same mismatch condition.

A Reconfigurable CMOS Inverter-based Stacked Power Amplifier with Antenna Impedance Mismatch Compensation for Low Power Short-Range Wireless Communications

“…The proposed PA can minimize the degradation of the output power under the worst antenna impedance mismatch conditions, and will become a good candidate for miniaturized high-efficiency PAs for ULP short-range wireless communication systems. Power Consumption @ P sat (mW) 9.8 6.2 8.8 5 10.1 5 7.7 5 5.9 1 Simulation results, 2 Measurement results, 3 Tested at the output power of +2 dBm, 4 Tested at the saturated output power, 5 Total power consumption of whole transmitter (Tx).…”

“…The most common method used to compensate for antenna impedance mismatch, and to preserve the RF performance of a PA, is to use a tunable matching network (TMN) between the PA and the antenna [2][3][4]. To adapt to changes in antenna impedance, the TMN adjusts its impedance to match the overall impedance of the TMN and antenna to 50 Ω.…”