International Journal

This paper presents a detailed procedure to design substrate integrated waveguide (SIW) Tee-junctions with wide-range split-power ratio (from 1:1 to 1:8) and phase-balanced outputs. A set of curves was generated using an electromagnetic (EM) simulator to graphically determine the required parameters for the desired junction. Since such curves are provided, no further electromagnetic simulation is

The microstrip active patch antenna behaves like a resonant circuit/cavity with multiple resonant frequencies; furthermore, depending on the non-linearity of the device, it generates significant amount of second harmonic radiation. The location of the device on the patch that maximizes the fundamental radiated power output is found to be not the position corresponding to the minimum second harmoni

This paper presents a close but a beginner's perspective and a comprehensive review of microstrip filters with defected ground structure (DGS). The concept of DGS is inspired by photonic/electromagnetic bandgap structures (EBG/PBG) and metamaterials that are employed in microwave components to achieve a variety of performance enhancement features. Modeling of DGS and metamaterials as an L-C equiva

This paper, following up on the previous work, investigates the effect of the input coupler's load termination of a balanced amplifier in a beam-steering system. The noise generated in this load termination deteriorates the amplifier noise resistance, which increases the noise temperature due to a varying active reflection coefficient at the antenna ports as a function of scan angle. In reducing t

The paper describes a radar demonstrator that was used to collect L-band range profiles of illuminated ground surface. The measurement results are to be used by the Institute of Geodesy and Cartography as the reference data for satellite image interpretation. The demonstrator is a software-defined noise radar composed of commercial-off-the-shelf elements. The paper conveys the theory of scattering

This paper presents the design and measurement of two different switch matrix modules based on Radio Frequency Microelectromechanical System (RF MEMS) switches. The operational frequency range is between 25.5 GHz and 26.5 GHz for data links between a Geostationary Earth Orbit (GEO) relay satellite and Low Earth Orbit (LEO) satellites. The switch matrix implements a key functionality for tracking t

A fast imaging algorithm for real-time use in short-range (ultra-wideband) radar with synthetic or real-array aperture is proposed. The reflected field is presented here as a convolution of the target reflectivity and point spread function (PSF) of the imaging system. To obtain a focused 3D image, the proposed algorithm deconvolves the PSF out from the acquired data volume with high speed due to f

This paper presents the design of a multi-channel reconfigurable front-end architecture for a waveform-agile radar. At first the purpose of the design is explained following the status of research on software-defined radar at MTSR. A description of the proposed system architecture is given with details on sub-systems implementation. Then some preliminary results obtained on a prototype of the plat