Ultra−WideBand (UWB) technology was approved by the Federal Communications Commission (FCC) in February 2002 (FCC, 2002). According to the FCC regulations, the frequency band from 3.1 to 10.6 GHz can be used for short−range and high speed wireless communications systems. This recent allocation of a very wide spectrum of frequencies for the devices uses, with effective isotropic radiated power (...

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...

This paper proposes a microstrip patch antenna for 2.45 GHz Industrial Scientific Medical (ISM) band Wireless Body Area Network (WBAN) applications. To enhance the front-to-back ratio (F/B) and specific absorption rate (SAR), an electrically coupled LC resonator is introduced. The overall dimensions of the proposed antenna are 54 mm × 45 mm × 2.4 mm and it has a gain of over 1 dBi for the entir...

In this article, a time-domain test on the negative group delay behavior of double-Li-structure microstrip circuit is proposed. The feasibility validated experimentally using Gaussian envelopes modulating sine carrier frequencies inside and outside frequency bands.

A broadband left-handed parallel-line microstrip coupler is implemented by both electromagnetic simulation and actual fabrication. The circuit dimensions are smaller and more compact than those in previous studies and a thinner Duroid substrate of thickness h 0.635 mm is used. Parametric studies were performed using IE3D, and fabrication was done via a Quick Circuit 7000 prototyping machine. Th...

Simple broadband microwave interconnects are needed for increasing the size of focal plane heterodyne radiometer arrays. We have measured loss and crosstalk for arrays of microstrip transmission lines in flex circuit technology at 297 and 77 K, finding good performance to at least 20 GHz. The dielectric constant of Kapton substrates changes very little from 297 to 77 K, and the electrical loss ...

A new Sierpienski & Crown Square Fractal Shapes Slotted Microstrip Patch Antenna is proposed. A patch antenna is a narrowband, wide-beam antenna. These antennas are low profile, conformal to planar and non-planar surface, simple and inexpensive to manufacture using modern printed circuit technology, mechanically robust when mounted on rigid surface, compatible with MMIC designs and when the par...

This article presents a wideband bias circuit with low parasitic inductance for high-power pulsed amplifiers. The proposed works similarly to the traditional in that it can ensure transmission of microwaves from power amplifier load while preventing supply. By making line shorter and wider than circuit, reduces its inductance. reduction parameters is critical reducing drain voltage overshoot pu...

Finite-Difference Time-Domain (FDTD) subgridding schemes can significantly improve efficiency of various electromagnetic circuit simulations. However, numerous subgridding schemes suffer from issues associated with stability, efficiency, and material traverse capability. These issues limit general applicability of FDTD subgridding schemes to realistic problems. Herein, a robust nonuniform subgr...