International Journal

A new circularly polarized planar array antenna using linearly polarized microstrip patches is designed and optimized for X-band wireless communication applications. Four square patch elements with feed network are used to design the circularly polarized array antenna. The feed network consists of microstrip lines on the obverse side of the dielectric substrate and slot line on the reverse side of

This paper presents an innovative design of an Ultra Wide-Band (UWB) impulse radiation source. The transmitting system is composed of an UWB antenna with an integrated optoelectronic generator, which is able to feed the system with appropriate waveforms, a pulsed high voltage source, and an optical command system. The radiation source is the elementary part of a forthcoming short-range UWB Radar w

This paper presents small balanced bandpass filters exhibiting wide differential-mode pass bands and high common-mode suppression. The filters are implemented in microstrip technology and their topology consists of multisection mirrored stepped impedance resonators (SIRs) alternating with mirrored interdigital capacitors. The mirrored SIRs provide the required common-mode transmission zeros to ach

Impedance tuners are key instruments used for load- and source?pull measurements. They are crucial for any active microwave components, circuits, and systems characterization and optimization. This paper reports theoretical, simulated, and experimental results related to the development of a novel programmable impedance tuner offering high-voltage standing wave ratio (VSWR). After presenting the p

Traditional near-field antenna measurements use the sampling theorem to reconstruct the antenna pattern perfectly. However, a large number of measurement points are required for this approach. To address this problem, in this study, we propose a technique to accelerate the near-field antenna measurement, which is achieved by sparse E-field sampling in the region where the E-field changes smoothly

A novel transmission-line model is used for the analysis of planar structures, including wire-medium (WM) slabs with vertically aligned wires. The network formalism allows for an effective determination of the relevant spectral Green's functions, of the modal dispersion equation via transverse resonance, as well as of the far-field radiation pattern produced by simple sources via reciprocity, as o

This paper presents a new class of quasi-elliptic pass-band filters in substrate-integrated waveguide technology, which exhibits compact size and modular geometry. These filters are based on mushroom-shaped metallic resonators, and they can be easily implemented using a standard dual-layer printed circuit board manufacturing process. The presented filters exploit non-resonating modes to obtain cou