Dual-band omnidirectional coupled-fed monopolar filtering antenna

A low‐profile high‐gain filtering patch antenna with harmonic suppression

“…Recently, direct modifications to the antenna radiation structure have been used to solve these issues. [5][6][7][8][9][10][11] Examples include etching slot in Chen and colleagues, [5][6][7] using multiple patches in Yuan and colleagues, 8,9 and moving the coupled feed line in Zhang et al 11 All of these have the ability to alter the antenna's surface distribution current, cancelling the far-field radiation at a particular frequency to produce the filtering effect. Due to the absence of the filtering circuit, the antenna structure is more straightforward.…”

“…Such antennas are larger in size, higher in loss, and not significantly improved in gain. Recently, direct modifications to the antenna radiation structure have been used to solve these issues 5‐11 . Examples include etching slot in Chen and colleagues, 5‐7 using multiple patches in Yuan and colleagues, 8,9 and moving the coupled feed line in Zhang et al 11 All of these have the ability to alter the antenna's surface distribution current, cancelling the far‐field radiation at a particular frequency to produce the filtering effect.…”

Compact metal‐printed filtering antenna with wideband performance

“…4,5 Obviously, the additional introduction of filtering function would increase the structure complexity of the antenna. Thus, various approaches are studied to solve this issue, such as integrating filters in the feeding network of antennas, 6,7 loading parasitic elements, [8][9][10] or using stacked structures with cross-coupling. 11 Among these investigations, the cavity-backed filtering antennas are one of the most popular candidates for filtering antenna design, due to its attractive properties like high radiation efficiency and high gain.…”

“…Obviously, the additional introduction of filtering function would increase the structure complexity of the antenna. Thus, various approaches are studied to solve this issue, such as integrating filters in the feeding network of antennas, 6,7 loading parasitic elements, 8–10 or using stacked structures with cross‐coupling 11 …”

A filtering patch antenna with reflectionless in a wide frequency range

“…Without complex filtering circuits, filtering antennas using fusion design method had been studied in recent years. Many technologies, such as parasitic patch, 4,5 shorting pin, 6,7 open stub, 8 slots, 9,10 feeding network, 11,12 stacked patch, 13 as well as coupled-fed via-loaded annular ring, 14 are applied to design this kind of filtering antenna, and more compact antenna size can be realized.…”