A SiGe HBT power amplifier with integrated mode control switches for LTE applications

Abstract

A novel broadband multiport reflectometer, consisting of a standard 4 3 4 Butler matrix and an additional directional coupler is proposed. It is shown that such a reflectometer provides highly uniform tunable measurement conditions allowing for measurement precision enhancement. The impact of the applied directional coupler's imperfections on the measurement conditions has been theoretically analyzed. The high measurement accuracy of the proposed reflectometer has been proved experimentally by reflection coefficient measurements over the frequency range of 1-5 GHz, which show a good agreement with the results obtained using VNA.

Design of 900 MHZ Sige Power Amplifier With Linearization Bias Circuit

“…Even so, as a power amplifier is also indispensable in many other important applications such as radar system [4], base station [5], etc., researchers turned to SiGe power amplifier [6], since it not only is superior to CMOS power amplifier on frequency response and power gain, but also can be integrated well with CMOS technology while its speed and power performance have been comparable to GaAs technology. So the SiGe power amplifier has attracted much research interest in this field [7][8][9].…”

A multiband power amplifier using a switch‐based reconfigurable matching network for optimized power performance

“…The efficiency degradation of PAs at low power level was compensated by various envelope tracking‐based techniques , but the efficiency of PAs for long‐term evolution (LTE) handset applications was still low at frequently‐used large back‐off power levels . To improve the efficiency of PAs at low power levels, dual‐path PAs to separately optimize efficiency at high and low power levels were studied . However, the bandwidth of their matching network and impedance transformer was limited for LTE applications.…”