A compact flexible fractal ultra‐wideband antenna with band notch characteristic

Abstract

A compact flexible fractal ultra‐wideband antenna with band notch characteristic is presented. The antenna is printed on a 12.5 μm flexible polyimide substrate, and an impedance bandwidth of 15.48 GHz (3.6‐19.08 GHz) is achieved along with an overall antenna size of 20.5 × 13.9 mm2. The design of the hexagonal radiator in the fourth iteration effectively enhances the impedance bandwidth of the antenna. By arranging two symmetrical complementary split ring resonators on the ground plane, the band rejection of the X‐band uplink frequency from 7.9 to 8.41 GHz is achieved. The average gain of the antenna can reach 3 dBi in the pass band, while the gain in the notch band is greatly reduced to below 0 dBi. Compared with the existing structure, the antenna has a larger bandwidth and a smaller size. Furthermore, the antenna is tested under bending effects. Test results show that this antenna can be used for integration on flexible electronic devices.

Uwb Monopole Antenna With Dual Notched Bands Verified by Characteristic Mode Analysis (Cma)

“…To overcome this interference problem, the UWB antennas with band-notch characteristics are desirable. For achieving notch characteristics with UWB elements, several techniques have been reported in the literature [4][5][6][7][8][9][10]. The commonly used methods are based on etching slots on the radiating surface and/or in the ground plane [4][5][6][7], adding a parasitic element(s) near the radiating element, etc.…”

“…The commonly used methods are based on etching slots on the radiating surface and/or in the ground plane [4][5][6][7], adding a parasitic element(s) near the radiating element, etc. [8][9][10]. Usually, one slot/parasitic element is sufficient to generate a single-notch [11].…”

Strong coupling induced notched bands of UWB antennas using meta-surfaces

“…Among all the band-notched antenna designs, the trapping wave technology using notched structures has widely been employed in such a research area for its simple design and efficiency. Such a strategy generally uses specific etched or printed resonant structures to obtain the desired band-notched performances, through carving slots [1][2][3][4][5], adding parasitic elements [6][7][8][9][10][11][12][13], appending matching stubs [14][15][16] on the original antennas, thus offers very practical solutions to the band-notched antenna designs. In addition, carving tapered-shape slot in the ground plane [17] or using partial ground plane [18] can influence the coupling between the patch and the ground plane, thus enhances the operating bandwidths of the ultra-wideband (UWB) antenna.…”

A novel modified hexagonal fractal antenna (HFA) with band notches for WLAN rejection

“…The miniature concept introduces a word 'fractal' to the UWB system which possess various Koch, Sierpinskicarpet, minkowski, cantor, square, triangular geometries (Ryu and Kishk, 2009;Mishra et al, 2011;Chaouche et al, 2018;Sharma and Bhatia, 2019;Harkanche et al, 2018;Bukkawar and Ahmed, 2018;Kim and Park, 2006;Pharwaha et al, 2018;Wu et al, 2010;Xiao et al, 2014;Sreerag and Sudha, 2014;Zou and Jiang, 2020;Zhou et al, 2008). The original concept of fractal came from the in-depth study of patterns of nature.…”

“…Notch functions are highly desirable to mitigate interference between UWB and narrow band spectrum. To avoid interference, different design methods have been proposed earlier like cutting of slots on the patches (Kim and Park, 2006;Pharwaha et al, 2018;Wu et al, 2010;Xiao et al, 2014) or quarter wavelength tuning stubs within the slots on the patch , etching different compact co-planar structures (Sreerag and Sudha, 2014;Zou and Jiang, 2020), using fractal slots and parasitic elements (Ryu and Kishk, 2009;Zhou et al, 2008). However, most of these designs are very complicated as they lead to increase in fabrication costs and difficult to integrate with microwave integrated circuits.…”