Bevelled Rectangular Monopole with Shorting Strip
Image of the Bevelled Rectangular Monopole with Shorting Strip.

UWB applications are being used in many industries today. These applications require low cost solutions with wide frequency band operations. Planar monopoles (realised by replacing the wire element of a conventional monopole with a planar element) are a family of antennas which are able to meet these specifications.

The antenna designed here is similar to the rectangular (trapezoidal) monopole in Antenna Magus. The addition of a monopole-to-ground shorting strip, and a bevelled shaped cut-out increases the operating bandwidth of the standard rectangular monopole (2:1) dramatically. The shorting strip counteracts the reactive nature of the rectangular monopole by adding inductance/capacitance over the frequency range. The bevel shaped cut-out further reduces the low frequency reactive component. A good reflection response (below -8dB) across a bandwidth of 14:1 is achieved.

VSWR comparison between different monopole topologies
Total gain: 1.125fmin, 3fmin, 7.25fmin and 14fmin