Design of a radio frequency compensation system, using the electrical characterisation of a multi-transducer acousto-optical tunable filter

Acousto-Optical Tunable Filters (AOTFs) make use of the interaction between sound and light. To generate an ultrasound diffraction grating, a Radio-Frequency (RF) signal is applied to a piezoelectric transducer. The optical pass band can be controlled by adapting the properties of this transducer and the RF-signal. To achieve more precise...

PA Output Power and Efficiency Enhancement Across the 2:1 VSWR Circle using Static Active Load Adjustment

This paper proposes a power amplifier (PA) correction technique to recover from load mismatch. It utilizes a main PA, two auxiliary PAs, and a coupler. By adjusting the input drive levels of the PAs it can recover the output power and to a great extent the efficiency of the main PA even when exposed to 2:1 VSWR mismatch conditions. When...

A Load Insensitive Doherty Power Amplifier with better than −39dBc ACLR on 2:1 VSWR Circle using a Constant 50 Ω Trained Pre-distorted Signal

This paper presents a low-loss load-insensitive Doherty power amplifier (DPA) technique. The proposed DPA is insensitive to ohmic load variation by adjusting its supply voltages and input drive of the main and peaking stages in a mirrored approach. Moreover, a low-loss tunable matching network (TMN) is employed to cancel out any reactive part of...