Peter Waldow

Simulation of Waveguide Structures Using the TLM Method in Time Domain

In this article various problems are addressed. First, the simulation of the longitudinally homogeneous structures is discussed. The technique presented is based on the travelling wave principle, which renders possible a drastic reduction of the storage and the computation time demand as well. Thereafter, the longitudinally periodic structures are treated. It will be shown how the originally proposed technique for solving this problem can be modified. The applicability and the efficiency, respectively, of the solutions proposed of the problems mentioned above are finally explained by means of results derived from the analytical parameter estimation and some simulations.

A technique for analysing UWB antennas using the TLM method

In this paper, a technique for antenna analysis with the help of Transmission Line Matrix (TLM) Method is presented. In order to simulate a free space environment the TLM method requires the use of an absorbing boundary condition. The latter is realized by the EPML (extended perfectly matched layer). For the applicability of the technique proposed, a bow-tie and Vivaldi antenna are analyzed. Subsequently, numerical, as well as experimental results are introduced and discussed. These results obtained demonstrate the capability of this simulation technique for practical broad-band antenna design.

An experimental low-voltage I-band oscillator assembled with only five SMD-components

An easy to assemble experimental I-band oscillator which uses only five SMDcomponents is described. The resonant circuit is built up by two microstrip lines and an interdigital capacitor etched on a common FR4 substrate, respectively. Only two junction field-effect transistors (JFETs), two capacitors and one resistor are necessary to build up this low-cost oscillator. With a supply voltage of 3.0 V, an output power of more than 1 mW is achieved at an operating frequency of 9.24 GHz. The measured suppression of the harmonics is better than 55 dBc. The realised oscillator has small geometrical dimensions and is very well suited to be manufactured as a monolithic microwave integrated circuit (MMIC), too. Integrating an additional tuning diode Will enable the oscillator to serve as a low-voltage VCO in a smallband PLL circuit.