Compact UWB Bowtie Antenna with Triple Rejection Bands

A compact planar microstrip bowtie-shaped antenna has been designed for UWB wireless applications. The designed antenna has been optimized to reject three frequency bands to avoid interference with the applications utilized in these bands. The antenna is designed on 1.6 mm thick FR4-substrate and fed by 50 Ω microstrip feed line. Two quarter wavelength transformers are introduced to enhance the impedance matching. The bowtie right side has a horizontal slit to enhance the bandwidth and it is connected to the microstrip feed line, while its left side is composed of a parasitic of bowtie shaped and a microstrip line connected to the partial ground plane in the back side through a shorting pin. The proposed antenna is investigated using the high-frequency structure simulator (HFSS). The simulated scattering parameter S
11
(Reflection Coefficient) result shows bandwidth ranges from 1.95 to 12.92 GHz at return loss (RL = |S
11
|) ≥ 10 dB with rejection bands of (2.13 – 3.96) GHz, (4.42 – 5.53) GHz and (7.51 – 9.3) GHz. The proposed antenna can achieve a maximum gain of 5.85 dB. The patterns exhibit an omnidirectional shape at lower frequencies.