Bandwidth Improvement Methods of Transmitarray Antennas

Bandwidth Improvement of Reflectarray Antennas Using Closely Spaced Elements

A bandwidth improvement method in reflectarray antennas by using closely space elements, i.e., unit-cell sizes smaller than λ/2, has been investigated both numerically and experimentally in this paper. A new definition of phase error has been introduced to analyze the broadband mechanism of closely spaced phasing elements. Through full wave EM simulations, it is revealed that closely spaced ele...

A Nonlinear Technique for Bandwidth Improvement in Narrowband Antennas

Optimization of the Bandwidth of Electrically Small Planar Antennas

The bandwidth limitations of resonant, electrically small antennas that fully occupy a spherical volume are well defined by the inverse of the Chu-limit or the lower bound on quality factor. Recently, Gustafsson et al developed lower bounds for the Q of antennas of arbitrary shape. We have previously described antenna designs fully occupying a spherical volume and a cylindrical volume that exhi...

Bandwidth Improvement of Microstrip Crossed Monopole Antenna

A compact size low profile microstrip-fed crossed monopole antenna for ultra wideband communication is presented. The impedance bandwidth of a microstrip crossed monopole antenna has increased with a suitable dimension of ground plane and rectangular patch. The aim of this paper is to improved bandwidth and return loss of a Crossed Monopole Microstrip patch antenna and study the effect of anten...

Improvement of a data based bandwidth selector

A recently proposed data based method for choosing the bandwidth of a kernel density estimator is considered. Intuitive and asymptotic reasons are given for why the selected bandwidth should be smaller than is appropriate. This conflicts with the results of a simulation study. The conflict is resolved through a deeper asymptotic analysis. Further simulation results investigate the issue of what...