A novel differential filtering patch antenna with high selectivity

Abstract

A novel differential filtering antenna with high selectivity is proposed. The antenna is mainly composed of three different‐size patches, a slot, a pair of differential feeding lines, and a line resonator. An air gap is adopted to improve the impedance bandwidth and the filtering performance. The line resonator helps to generate high common‐mode (CM) rejection. Owing to the parasitic concave and convex patches, the filtering performance and the bandwidth of the antenna are enhanced. The parasitic concave patch affects the lower band‐edge selectivity while the parasitic convex patch influences the upper band‐edge selectivity. In addition, the frequencies of two radiation nulls can be controlled independently to achieve two high sharp roll‐off rates by adjusting the lengths of the parasitic patches. Considerable impedance matching bandwidth is achieved through an aperture coupling. Finally, a prototype of the differential filtering antenna is fabricated and tested. The measured results are in good agreement with the simulated results, showing an impedance bandwidth of 9.9% and an average realized gain of 7.5 dBi. Besides, two filter zero transmissions located at 3.40 and 3.84 GHz produced two radiation nulls.

Compact Differential-Fed Planar Filtering Antennas

“…The antenna radiation pattern is slightly narrower in the yz plane compared to the xz plane. In the two main planes, the cross-polarization level is less than 45 dB, which is a typical feature of differential-fed antennas [5,20]. Table 1 summarizes the spatial radiation characteristics of the optimized antenna.…”

“…Filtering antennas are components designed to offer antennas with specified filtering responses to decrease interference with surrounding wireless systems [5][6][7][8][9]. The design of filtering antennas is currently accomplished by following one of two approaches.…”

“…This approach has the drawback of increasing both the insertion loss and the footprint of the whole circuit. The second approach uses parasitic elements inside/near the antenna structure [5,6,9]. This approach is suitable for narrow band antennas, such as microstrip antennas; however, it typically requires a redesign of the antenna to account for the presence of the parasitic objects.…”

“…This approach is suitable for narrow band antennas, such as microstrip antennas; however, it typically requires a redesign of the antenna to account for the presence of the parasitic objects. Moreover, this latter strategy is typically time-consuming and may result in structures that are complex to fabricate [5,11]. In a recent work, Liu et al [6] proposed to suppress the out-of-band radiation of a filtering patch antenna by using dissipative resistors.…”

A Jia-shaped artistic patch antenna for dual-band circular polarization

“…It is therefore very meaningful to have the Chinese character Jia-shaped patch antenna presented in this article. The patch antennas embed Chinese character(s) into the antenna design, combining Chinese culture and antenna technology to realize the application of hidden antenna technology [3][4][5][6][7][8][9][10][11][12] that is suitable for indoor wireless communications to date. Chinese hieroglyphs are the crystallization of the wisdom of the Chinese nation.…”