International Journal

Detecting time-varying target in non-stationary background is difficult and attractive problem. Time-varying movement exists widely in radar and communication systems. The non-linear processing with higher moments is discussed in the situation. Firstly the signal model of time-varying target with fix acceleration is analyzed. Then the radar echoes from synthetic aperture radar (SAR) are processed

We propose a definition of the efficiency bandwidth for a power amplifier (PA) using a modulated signal as the signal bandwidth at which the amplifier efficiency has dropped to a level of 90% of the maximum efficiency at small bandwidth. We introduce a Monte Carlo method to calculate the efficiency bandwidth for some popular PA architectures. The method assumes a given modulated signal at the load

The substrate-integrated cavity-backed patch antenna embedded in dielectric-coated structure is presented. The aperture of antenna is covered with composite radome. The close proximity of radome to antenna severely degrades input impedance matching. The dielectric coating, a thick dielectric material, significantly deteriorates radiation pattern of antenna due to propagation of surface waves in th

In this paper, a microstrip fed, L-shape slot antenna for dual polarization is proposed. The two arms of the slot generate electric fields of orthogonal polarizations. By properly sectioning the slot and the feed line, ultra wideband (UWB) behavior is obtained. The measured impedance bandwidth ( < ?10 dB) is more than 8.6 GHz (112%) and 8.2 GHz (104%) for Port 1 and Port 2, respecti

A fast and efficient full-wave hybrid method for the analysis of a multilayered substrate integrated waveguide (SIW) based slot antenna/array radiating into a dielectric slab radome is presented. The antenna structure is modeled as a stacked parallel-plate waveguide hosting metallic posts and coupling and/or radiating slots. To account the radome effects on the SIW antenna, the physical optics met

A reactive impedance surface (RIS) based miniaturized bent slotted patch antenna is proposed and investigated for S-band applications around 2.39 GHz. Bent slots in the patch reduce the patch antenna size by increasing current path on the patch. Further a RIS substrate with cross-shaped patch elements printed over a grounded dielectric is optimized and investigated for antenna miniaturization. The

In this paper, we propose a novel integrated ultra-wideband (UWB) monopole antenna with dual-band antenna. The antenna consists of planar rectangular with semi-elliptical base and a rectangular dielectric resonator antenna (DRA) with dual-band operation. Both of them are excited via coplanar waveguide (CPW) lines. The experimental measurements show that the planar monopole provides an impedance ba

A new simple compact ultra-wideband (UWB) dielectric resonator antenna is presented. The antenna consists of a modified stepped microstrip-fed monopole printed antenna loaded with a rectangular dielectric resonator, truncated ground plane, and a parasitic strip underneath the dielectric resonator (DR). Using an optimized truncated ground plane and a combination of stepped feed line with DR an ultr

This paper presents three iterations of a coplanar waveguide-fed H-tree fractal antenna. Increasing the number of iterations allows us obtaining a multi-band and broad-band behavior. The proposed antennas are a good solution for wireless local area networks IEEE802.11 a/h/j/n/ac/y, worldwide interoperability for microwave access system IEEE802.16, radio frequency identification, C-band, high perfo

A finite-ground coplanar waveguide (FGCPW)-fed compact ultra-wideband flag-shaped monopole antenna is presented. The antenna consists of a FGCPW-fed monopole asymmetrically loaded with a rectangle strip. The antenna has a compact size of 21.85 × 28 × 1.6 mm. Parametric analysis is conducted to understand the effect of various parameters on the antenna performance. Simple design equations are prese