Feasibility of incorporating a low profile di planar inverted cone antenna and a microwave amplifier in the design of a broadband E-field probe.

摘要

The goal of this thesis is to perform a feasibility study for the design of a broadband Electric field (E-field) probe to measure E-fields in the 1--6 GHz frequency range, specifically inside a microwave anechoic chamber. The E-field probe incorporates a low profile di Planar Inverted Cone antenna (LPdiPICA) and a microwave amplifier.;An E-field probe is a device that is used to measure E-fields in different indoor or outdoor environments. It typically consists of the following basic elements: a dipole antenna which has an omni-directional pattern, a detector mounted across the gap that separates the two arms of the dipole for rectifying the measured signal, a transmission cable connecting the detector output with a remote observation site, and the ability to measure accurately a wide range of field strengths over a wide bandwidth of frequencies.;The E-field probe designed in this thesis incorporates a LPdiPICA as the receiving element instead of the commonly used dipole antenna. The LPdiPICA is selected due to its broadband performance in terms of impedance and radiation pattern bandwidth. The effect of reducing the LPdiPICA dimensions to a quarter of its original size so that it is of reasonable physical size for use in an E-field probe is investigated. However, this decreased the impedance bandwidth at the lower frequency side. Several techniques including (1) Increasing the relative dielectric constant and thickness of the substrate, (2) Increasing the width of the antenna while maintaining the length constant and, (3) Wire loading the antenna, are investigated as a possible means of increasing the bandwidth. These results are presented and discussed.