Design Method for UWB Planar Antenna with Subband Rejection Capability

A simple guideline for designing a compact planar antenna is presented. The objective of the design is to have a bandwidth covering the range from 3.1 GHz till 10.6 GHz, assuming a 10 dB return loss reference. The proposed antenna has the capability to reject any undesired subband within the whole bandwidth of its operation by incorporating a tuning slot within the radiating structure. Assuming GML1032 dielectric substrate with relative permittivity of 3.2, the designed antenna features a compact size of 27 mm × 27 mm. Results of simulation show that the designed antenna has a 10-dB return loss bandwidth from 2.8 GHz to more than 11 GHz excluding any undesired subband, such as the 4.9-5.9 GHz band assigned for IEEE802.11a and HIPERLAN/2. The antenna has near omnidirectional characteristics, and its radiation efficiency is higher than 90 % over the whole pass-band.