The existing UHF Satellite Communications (SATCOM) transponders used for military applications use efficient, saturated power amplifiers, which provide one earth-coverage antenna beam. The amplifier is dedicated to small frequency band and only handles a few carriers simultaneously. The communications capacity needed to support future military forces on the move will require satellite payload p...

This study presents a high-fidelity and high-efficiency digital class-D audio power amplifier (CDA), which consists of analog modules. To realize compatible input, fully digital-to-analog converter (DAC) is implemented on MATLAB Xilinx System Generator, 16x interpolation filter, fourth-order four-bit quantized delta-sigma (ΔΣ) modulator, uniform-sampling pulse width modulator. The CDA utilizes ...

For wideband or high power applications, the power amplifier exhibits memory effects, for which memory less predistorters can achieve only limited linearization performance. The memory polynomial predistorter can correct both the nonlinear distortions and the linear frequency response that may exist in the power amplifier. It is a robust predistorter, which has demonstrated good performance on ...

According to the shortage of the traditional offset line in Doherty power amplifier, a new offset line technique is proposed to match carrier amplifier with the load and to improve the performance of the Doherty amplifier. By simulation of the computer software, a higher efficiency is obtained using the new offset line comparing the two kinds of offset lines. The new offset line technique could...

A high DC-gain low-power current recycling amplifier using positive-feedback technique is presented. In the proposed amplifier, the positive-feedback signal used to enhance the DC-gain is derived from the extra nodes created by cascoding. Positive-feedback offers the ability of obtaining a very high DC-gain, ideally infinite gain, without affecting high frequency performance and stability. Unde...