Ultra wideband (UWB) accordion monopole antenna

Image of the Ultra wideband (UWB) accordion monopole antenna.

High data speeds and multiband operations of modern wireless communication systems have significantly increased the demand for simple, but very broadband antennas. In general, the systems need low-cost solutions with application-specific requirements in terms of impedance bandwidth, polarisation and gain. Planar monopole and dipole antennas are often good options here - though they usually have a high profile above the ground-plane.

The UWB accordion monopole achieves a much wider impedance bandwidth than most other planar monopoles, including popular structures like the Circular disc monopole and the Rectangular monopole with a semicircular base. While an impedance bandwidth of up to 38:1 is reported (see graph image below), the uniformity of the azimuthal pattern is only retained for a 3.4:1 bandwidth as shown in pattern comparisons in the second image below. The exceptionally wideband operation of this structure also makes it a good candidate for ultra wideband pulse applications.

Typical normalised reflection coeefficient of the UWB accordian monopole.
Typical 3D Radiation patterns vs frequency.