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A significant linearity improvement of the power amplifier (PA) performance designed for and subjected to dynamic gate bias operation, is shown in a comprehensive computer simulation. Simulation was based on a data measured with a time domain measurement technique. A dynamic gate biasing technique was used to keep the phase of the PA flat until PA reaches deep compression level in order to reduce...
This paper presents investigation on how linearity performance changes for different gate bias voltages for the ET and AET 10 W GaN HEMT power amplifier. It is shown that by selecting optimal gate bias voltage, AM-AM and AM-PM transfer characteristics can be more constant for a given power dynamic range which results with better linearity. Moreover, the efficiency can stay preserved. Benefit of selecting...
An optimization method for the variation of bias with input power, also referred to as dynamic biasing, is presented and applied to an unmatched InGaP 21-dBm heterojunction bipolar transistor (HBT). For a modulated signal with a crest factor of 6.5 dB, the optimization yielded two solutions for an output power of 14.8 dBm: one with 40% power added efficiency (PAE), the other one with 22%, which is...
Driving the gate and drain biases as a function of the input power significantly enhances the efficiency of class-A and -AB amplifiers. These functions are described as low-order polynomials in order to limit the bias bandwidth, especially at the drain. This work formulates the optimization of the bias polynomial coefficients as a constrained optimization problem, describing in detail the formulation...
A six bit impedance tuner is presented. The tuner consists of six switched RF-MEMS capacitors distributed along a length of CPW transmission line, producing 64 different impedance states. This tuner is capable of tuning to a VSWR of 30:1 at 6 GHz and to VSWR of 110:1 at 16 GHz, with a loss better than 0.7 dB. The impedance tuner is designed to have a 50 Ω impedance from 6 to 18 GHz with all the switches...
A mixer solution that ensures good linearity and almost constant conversion loss over a given frequency band is presented. The mixer solution allows for relatively large variations in the LO input power with negligible performance degradation. A good match at all mixer ports is provided, hence the mixer allows for easy integration with surrounding radio modules. All the components used in the unit...
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