The synaptic antenna for reconfigurable array applications-behavior

Abstract

The Synaptic antenna is a matrix of thin conductive line segments joined (synapsed) at nodes with photoconducting cells (Photistor') which can be switched on by optical energy alone We report on the input impedance and gain patterns of some horizontal dipole arrays. The broadside 2-dipole array and the collinear dipole pair, with and without parasitic elements. BEHAVIOR OF VARIOUS ANTENNASThe behavior of a Synaptic antenna can be analyzed with a thin-wire version of the computer code NEC 111. The various antennas of interest are constructed by appropriate optical feeds to have the conductive elements shown in Figures 4 and 5 of reference [Z]. A. The Single Horizontal Half-Wave Dipole (a) in Figure 4 [ Z ] .For this antenna M = N = 15. The horizontal arms are X/4 above the ground plane atop the substrate. Frequency was 1 gHz (A = 30 cm). Each segment was either-X/12 long or half as long at the symmetry plane. The voltage generators feeding the two arms produced the current flows indicated by the arrows. The impedance for each generator is 100.1 -j6.7 ohm. Radiation efficiency is 66.7%.The E-plane (@ = 0) relative gain pattern for the major-axis elliptically polarized radiation field and the corresponding H-plane (@ = 90') pattern are shown on the right half of Figure 1. The patterns are symmetric about the 8 = 0' or Z-axis in each plane. Each pattern is relative to the maximum isotropic gain of 5.86 dB shown at 8 = 30', 0 = 90' (or 270 ').Note that the relative gain at 8 = 0 is the same at 0 = 0 and 90 ' because the major-axis radiation field is the same in this direction.The corresponding patterns of the same antenna but without the matrix substrate appear on the lefl side of Figure 1. The impedance for each generator has increased greatly, to $;