Investigation on the effects of resistive loading on wrapped bow-tie antennas

Abstract

The pulse radiating characteristic of a wrapped bow-tie antenna (WBA) and wrapped resistively loaded bow-tie antenna (WRLBA) is presented for impulse radar applications in this paper. The numerical analysis of the WRLBA is performed by comparing that of the WBA. The wrapped antennas are realized on a flexible substrate. The antennas are fed by an impedance tapered balun, which has an overall transmission loss of −1.4 dB over the balun length. The characteristics of the resistive loading to the wrapped antenna, such as reflection coefficient, reflected pulse in the time domain, voltage standing wave ratio, and input impedance, are experimentally investigated and compared with simulated results. The fidelity factor of the radiated electric field on the boresight direction for the WBA and WRLBA is calculated as 0.82 and 0.96, respectively. The wireless communication ability is evaluated by the transmission coefficient, group delay, boresight gain, and received waveform. The calculated fidelity factor of the received waveform for the WBA and WRLBA is 0.79 and 0.85, respectively. The average and variations of the group delay of both wrapped antennas are observed to be around 2.5 ns and less than 1.5 ns, respectively.

Metasurface Cloaks to Decouple Closely Spaced Printed Dipole Antenna Arrays Fed by a Microstrip-to-Balanced Transmission-Line Transition

“…The substrate (Rogers RT / duroid 5870) with 0.79 mm thickness is used with the dielectric constant of 2.33 and the loss tangent of 0.0005. The printed planar dipole antenna in this study is fed by the microstrip-to-balanced transmission-line transition, which not only transforms the impedance from 50 Ω to 188 Ω but also makes the end of the line balanced [44], [45], [46]. The balanced transmission line consists of the microstrip and parallel lines.…”

“…The width of each transmission line can be easily determined by using a microstrip line equation, which can be found in [47]. The parallel strip-lines, which have the same widths with respect to the signal and ground lines, can be designed by implementing an image theory to the original equation of the microstrip line [44], [45], [46]. The antenna parameters, as shown in Fig.…”