Design of a UHF wide‐band antenna with a compact notch filter

A novel ultra high frequency (UHF) broadband polygonal monopole antenna with a notch is presented. The antenna is a wineglass‐shaped geometry near two pairs of long‐horn‐shaped coupling elements located on the top and bottom surfaces to cover the band of 700 MHz–1.3 GHz with the size of 150 × 100 × 1.2 mm. The notch filtering is achieved at 900 MHz by using the open‐terminated stub of a novel composite right/left handed transmission‐line phase shifter. The phase shifter is 12 mm as 0.07 × λ g . The validity of the proposed scheme is verified by designing and comparing the wide‐band antenna with different notch‐making approaches through electromagnetic simulation, fabrication and measurement. The simulated and measured results show high degrees of agreement. The suggested antenna is shown to be useful for UHF‐band applications with a stopband at 900 MHz to avoid potential interference from the GSM‐E service, Z‐wave communication and UHF radio‐frequency identification tag frequencies.