In this letter, the design and measurement of the first SiGe integrated-circuit LNA specifically designed for operation at cryogenic temperatures is presented. At room temperature, the circuit provides greater than 25.8 dB of gain with an average noise temperature of 76 K and of 9 dB for frequencies in the 0.1–5 GHz band. At 15 K, the amplifier has greater than 29.6 dB of gain with an average o...

13 watt Current Mode Class-D (CMCD) with 60% efficiency is presented. This amplifier is the highest power switch mode microwave power amplifier reported to date. The CMCD architecture is an improvement over the Voltage Mode Class-D in that the parasitic reactance in the active device can be absorbed into the tank circuit resulting in a zero voltage switching condition.

Bernhard Goll*, David J. Thomson, Lars Zimmermann, Henri Porte, Frederic Y. Gardes, Youfang Hu, Dieter Knoll, Stefan Lischke, Bernd Tillack, Graham T. Reed and Horst Zimmermann 1 Institute of Electrodynamics, Microwave and Circuit Engineering (EMCE), Vienna University of Technology, Vienna, Austria 2 Optoelectronics Research Centre (ORC), University of Southampton, Southampton, UK 3 IHP, Im Tec...

This paper presents a comprehensive full-wave analysis of packaged nonlinear active microwave circuits by applying the extended finite-difference time-domain (FDTD) method. Based on the approach of using equivalent sources, the device–wave interaction is characterized and incorporated into the FDTD time-marching scheme. As a consequence, analysis of linear and nonlinear properties, including ha...

A new technique to reduce the size, improve the rejection in the stop-band of a low-pass filter using modified defected ground structure (DGS) is proposed. An equivalent circuit model is used to study the DGS characteristics. The parameters are extracted by using a simple circuit analysis method. Several comparisons between the EMsimulations and the circuit simulations of the new structure are ...

As experimental quantum information processing (QIP) rapidly advances, an emerging challenge is to design a scalable architecture that combines various quantum elements into a complex device without compromising their performance. In particular, superconducting quantum circuits have successfully demonstrated many of the requirements for quantum computing, including coherence levels that approac...

Periodic structures have been extensively used in the history of microwave engineering. Recently, there appears a significant renewed interest in this subject, due to highly publicized Photonic Crystals and Metamaterials. This lecture introduces basic theory on the electromagnetic aspects and circuit representations of periodic structures. Several practical examples are introduced. Some fundame...

An approach to design of chaotic oscillators with controlled bandwidth in different frequency bands is proposed. One of possible mathematical models of the oscillator and simulation results are considered. Implementations of microwave chaotic oscillators and experimental results are demonstrated. Index terms – Dynamic chaos, chaotic oscillator, frequency-selective circuit, microstrip line, wide...

Novel and computationally efficient method for optimization of microwave structures is presented. The technique is based on the adjustments of the design specifications and exploits the coarse model — computationally cheap representation of the structure being optimized, e.g., equivalent circuit. It is demonstrated that the proposed approach allows rapid design improvement while being simple to...

Application of multi-dimensional Cauchy approximation and coarse-discretization electromagnetic (EM) models to surrogatebased optimization of microwave structures is discussed. Space mapping is used as an optimization engine with the surrogate model constructed as a Cauchy approximation of the coarsely discretized device EM model. The proposed approach allows us to perform computationally effic...