Design of ultra‐wideband antenna with high‐selectivity band notches using fragment‐type etch pattern

Abstract

By specifying objective functions defining the two bands to be notched with high roll‐off criteria (ROCs), optimization searching for the best fragment‐type etch pattern on ultra‐wideband (UWB) antenna is implemented by using multi‐objective optimization. The optimization with too many objective functions requires special treatment to improve the searching efficiency. In this design, two slits are preset on appropriate positions on different sides of the UWB radiator to constrain the decision space for etch pattern searching and yield two initial notched bands to speed up the optimization. For demonstration, a UWB patch antenna is designed with dual‐band notches of ROC = 0.63 at WiMAX band and ROC = 0.65 at WLAN band. Both the simulation and measurement results indicate that there is significant improvement of the selectivity of the dual‐band notches.

A new type of compact ultra‐wideband planar fractal antenna with WLAN band rejection

“…Fractal geometries are also commonly used to achieve UWB characteristics with lower cutoff frequency . In the published literature, several UWB antenna designs with notch band characteristics in allocated frequency bands have been reported …”

Challenging the remarkably sharp roll‐off band notch with fragment‐type etch patterns

“…By applying multiple objective functions, ROC of the band notched in the FCC UWB can be further improved by implementing multi‐objective optimization searching. ROC = 0.72 is acquired for single‐band notch in Reference 9 and ROC = 0.63 at WiMAX band and ROC = 0.65 at WLAN band are achieved for dual‐band notch in Reference 10, which are the highest ROCs among various single‐band and dual‐band notch designs, respectively.…”

“…Due to the great flexibility of fragments in shaping high‐performance structure, fragment‐type etch patterns have found applications in band notch design with higher ROC 9,10 . By applying multiple objective functions, ROC of the band notched in the FCC UWB can be further improved by implementing multi‐objective optimization searching.…”

A compact flower slotted dual band notched ultrawideband antenna integrated with Ku band for ultrawideband, medical, direct broadcast service, and fixed satellite service applications

“…For the proposed FSA, the realized gain is −2.10 dBi at 5.6 GHz and -1.91 dBi at 7.4 GHz represents the antenna eliminates WLAN and X-band signals. Moreover, the gain varies from 2.21 to 3.55 dBi, except at notched bands over operating frequencies of FSA represents the proposed FSA gain is more stable than the reported antennas [22][23][24][25][26][27][28][29][30][31][32][33][34] in Table 3.…”