Development and Experimental Measurements of a Tunable Antenna

Abstract

<p class="MsoNormal"> <span lang="EN-US">Modern telecommunication systems need to be equipped with antennas that are precisely tuned to more than one frequency in order to allow operation in several bands. Antenna precise tuning to the desired frequency is very important for system performance. In this paper the operating frequency of a PIFA antenna is adjusted using a varactor. This configuration has the advantage of conti</span><span lang="EN-US">nuous</span><span lang="EN-US"> tuning, thus correcting any frequency deviation due to environmental or other changes. The PIFA antenna’s tuning ranges from 860 MHz to 1025 MHz. Also, the geometry of the antenna is studied through simulations and the effect of the varactor is tested experimentally.</span> </p

Novel Power Control Scheme for Target Tracking in Radar Network with Passive Cooperation

“…Simulation results are provided to demonstrate that, compared with other algorithms, a significant improvement of the LPI performance can be achieved through our proposed strategy. From a practical point of view, in the future, the proposed algorithm can be implemented in satellite communications as well as a system of using reconfigurable antennas and other emerging wireless technologies for finding more accurately targets [46][47][48][49]. In addition, the findings in this paper can be implemented in other scientific fields using the tracking technique to find a better cutoff point even using ROC analysis [50].…”

“…Thus, we formulate the following general form of the optimization problems in (38), (43), (48), and (50) In this paper, the optimal solutions to the unified nonconvex, nonlinear, and constrained optimization problem (51) can easily be obtained with NPGA, which has a good performance on the convergence speed, and it can improve the searching performance of ordinary genetic algorithm [28]. The NPGA is extremely effective in solving multidimensional optimization problems with non-convex and nonlinear constraints on the variables.…”

Microwave Structural Health Monitoring Sensor for Deformation Measurement of Bended Steel Structures: Influence of Curvature Effect

“…In the further work the directional characteristics of the rectangular microstrip sensor will be determined and the influence of the curvature effect for other directions will be studied. One of the ideas to minimize the influence of the curvature effect is application of tunable antennas [35][36][37].…”

A Novel Polarization Independent Wideband Circuit Analog Absorber Using Crossed Loops

“…Different absorbing configurations like ultra-narrowband to ultra wideband is attainable by ex-ploiting dielectric or ohmic loss of HIS structures [5]. These absorbers can be considered as another major development among orthogonal frequency division multiplexing systems, tunable antennas etc [6][7][8]. HIS based scatteres are also one of the major research area [9].…”