Reactive Matching Network Research Articles

Improvement of Small Signal Equivalent Simulations for Power and Efficiency Matching of GaN HEMTs

In high-frequency power-amplifier design, it is common practice to approach the design of reactive matching networks using linear simulators and targeting a reflection loss limit (referenced to the target impedance). It is well known that this is only a first-pass design technique, since output power or efficiency contours do not correspond to mismatch circles. This paper presents a method to improve the accuracy of this approach in the case of matching network design for power amplifiers based on gallium nitride (GaN) technology. Equivalent mismatch circles, which lay within the power or efficiency contours targeted by the design, are analytically obtained thanks to geometrical considerations. A summary table providing the parameters to use for typical contours is provided. The technique is demonstrated on two examples of power-amplifier design on the 6–12 GHz band using the non-linear large-signal model of a GaN High Electron Mobility Transistor (HEMT).

Reactive matching of millimetre-wave photodetectorsusing coplanar waveguide technology

The design, fabrication, and characterisation of a monolithically integrated narrowband photoreceiver on InP for 38 GHz operation is reported. The device comprises an ultrafast sub-half-micrometre InGaAs metal-semiconductor-metal photodetector and a reactive matching network based on coplanar waveguides. Compared to a purely resistive match, a 4 dB increase in the power transfer between the detector and the 50 Ω load is achieved.

Dual frequency wire antennas

A new type of dual frequency antenna is introduced by combining a helical and a monopole antenna. The antenna configuration is shown to operate at two discrete frequencies, i.e. ~900 and 1800 MHz. The size of the antenna configuration can be decreased at the cost of the bandwidth. The bandwidth is shown to increase by adding a reactive matching network to the antenna.

Monolithic integration of optoelectronic devices with reactive matching networks for microwave applications

Microwave impedance matching networks have been, for the first time, monolithically integrated with GaInAs p-i-n photodiodes and GaInAsP buried ridge stripe structure lasers ( lambda =1.3 mu m), both on a semi-insulating InP substrate. The microwave power transfer optical links were compared using matched and unmatched devices. Compared to an unmatched link, an improvement of 11.4 dB at 5.6 GHz (600 MHz bandwidth) is obtained for the totally matched one; this result corresponds quite well to the theoretical prediction (12 dB at 6 GHz).< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>