Novel Phase-Shifting Characteristic of CRLH Tl and Its Application in the Design of Dual-Band Dual-Mode Dual-Polarization Antenna

Abstract

Abstract-The phase-shifting characteristic of a novel composite right/left handed transmission line (CRLH TL) for two frequency points is analyzed in this paper. Samples of (90 • , 0 • ) and (180 • , 0 • ) phase-shifting TLs for two frequency points (f 1 , f 2 ) are deigned and the total length of the CRLH TLs has decreased by more than 77% compared to the conventional microstrip lines. Then a four way power divider made by three Wilkinson power dividers and interconnected with the (90 • , 0 • ) and (180 • , 0 • ) phase-shifting TLs is designed to feed an antenna with two different operating modes at two different frequency bands. Four radiating patches arranging symmetrically in a loop are printed in an upper substrate and connected with the four outputs of the feed network by four copper pins. When the four rectangular patches are excited by four sources with equal amplitude and phase at f 1 , metamaterial antenna with conical beam and linear polarization (LP) is achieved; while four sources with equal amplitude but 90 • phase difference for each adjacent output at f 2 leads to wideband antenna with broadside beam and circular polarization (CP). One antenna prototype with dual-band dual-mode dual-polarization property is fabricated and good agreements between simulation and measurement results are obtained. This single-feed patch antenna is valuable in wireless communications for its radiation pattern selectivity and polarization diversity.

Induction Coupling Between Jointless Track Circuits and Track-Circuit-Reader Antenna

“…Here, A d (x, x 1 ) and φ d (x, x 1 ) denote the amplitude and phase of I d (x, x 1 , t), respectively, and are given as [16] …”

An Improved Broadband Siw Phase Shifter With Embedded Air Strips

“…Its insertion loss is less than 3.2 dB at the frequency range from 9.7 to 11 GHz with the return loss of 10 dB. In addition, the phase shifters based on switched-line with loadedline [15] and the composite right/left handed transmission line (CRLH TL) [16] have been discussed. The bandwidths should be expanded for a wider application.…”

A Functional Microstrip Circuit Module for Annular Slot Antenna

“…Offering improved effectiveness in receiving communication signals and reducing multipath fading were reported as the advantages for reconfigurable circularly polarized states [7][8][9]. Wilkinson power divider and branch microstrip line have been used very often in reconfigurable polarization antenna as tuners to modify the orthogonal radiation modes [10][11][12][13][14]. However, the most disadvantage is that the complicated DC bias circuit must be carefully considered to compensate the inefficient feed structure for manipulating circular polarization [15,16].…”