Compact ultra-wideband slot antenna fed by coplanar waveguide and microstrip line with triple-band-notched frequency function

A compact ultra-wideband (UWB) printed slot antenna fed by coplanar waveguide (CPW) and microstrip line with multi-band-rejection characteristics is proposed. The small antenna fed by CPW and microstrip line has a volume of 40 × 22 × 0.8 × mm³. By adding an inverted U-shape slot on the tapered radiating patch, the antenna provides band-rejection characteristics. The centre frequencies of three notched bands at 2.4, 3.5 and 5.5 GHz can be adjusted by modifying the length of the inserted slot. Good agreement is achieved between the simulated and measured results. The measured impedance bandwidth of the proposed antenna ranges from 2 to 12 GHz for voltage standing wave ratio ≤ 2, excluding the rejection bands. The omni-directional radiation patterns of the fabricated antenna fed by CPW and microstrip line are presented, which show that the designed antenna is a good candidate for various UWB applications. The measured peak gain variation is less than 4 dB over the operating frequency band.