FE-BI Analysis of a Leaky-Wave Antenna with Resistive Sheet Termination

Abstract

Printed leaky-wave antennas offer the potential for a low-profile, wide-bandwidth antenna element that can be arrayed if desired. Microstrip leaky-wave antennas rely on the suppression of the familiar 0 EH mode and the propagation of the radiating 1 EH mode. It is well-known that above a critical frequency, this leaky-wave will propagate with little attenuation and that the phase difference between the two radiating edges of the microstrip leads to radiation. However, due to the limits of installation area, such antennas must be terminated in a manner that reduces back reflection. If this is not done, a standing wave is established on the antenna limiting its utility as a leaky-wave antenna in terms of front-to-back ratio and bandwidth. In this paper, the hybrid finite element-boundary integral method is used to investigate an antenna termination scheme involving the use of resistive sheet extensions to the antenna. It will be shown that such a termination increases the front-to-back ratio and usable bandwidth of the antenna as compared to an antenna without such termination.

Empirical analysis of the effects of parasitic elements on the half- width leaky wave antenna

“…When measured, the parasitic elements were each loaded (on each end) with 50Ω loads mimicking the performance improvement in pattern and VSWR determined in [7,9].…”

“…The finite difference-time domain (FD-TD) method was used to study this antenna [6] in addition to experiments. An alternative method is the finite element method that has the advantage of being able to model more complex geometrical aperture arrangements [7]. More recently, a linear array of leaky wave elements was examined using the finite element-boundary integral model [8].…”

A novel short leaky-wave antenna for suppressing the back lobes

“…In [6], suppressing the back lobes has been developed by an array topology. In [7], the use of resistive sheet extensions to the LWA could absorb the power of reflected wave. A matching load was worked out in [8] for wide bandwidth termination.…”

“…A matching load was worked out in [8] for wide bandwidth termination. Both in [7] and [8] are also based on the half-width LWA. By a second radiated path, a two-directional scanned LWA with aperture-coupled patch antenna arrays has been investigated in [9].…”