A compact broadside coupled dual notched band UWB-BPF with extended stopband

A miniaturized low‐cost microstrip‐to‐coplanar waveguide transition‐based ultra‐wideband bandpass filter with multiple transmission zeros

“…It can be observed from column 1 of Table 1 below that the proposed structure is developed on a low‐cost dielectric unlike others 2‐10,12,13 . Column 2 indicates that the proposed structure meets the FCC passband requirement of 3.1 to 10.6 GHz comfortably.…”

“…The presence of TZs at either passband edge is very crucial to the frequency characteristics of any BPF for its enhanced selectivity. From column 3, it is observed that the proposed structure possesses TZs at both the passband edges unlike, 2,3,7‐9,11‐13 which do not possess TZ at either passband edges, whereas 4‐6,10 possess TZ at only one passband edge. Column 4 depicts that dual notches of the proposed structure have good attenuation (>15 dB) at 6.1 (C band) and 8.1 GHz (X band).…”

“…This spectrum is also home to other RF sources like WLAN, C, X band, and so on, which are concentrated pockets of high power and often act as sources of interference to the UWB systems. For these UWB devices to operate interference free, researchers have designed and developed UWB‐bandpass filters (BPFs) with integrated multiple stopband characteristics 2‐13 . Dual passband notches were developed in these UWB filters using stubs acting on the wave cancellation principle, 2,3 slots engraved in the microstrip, 4,5 stepped impedance resonators (SIRs) placed along microstrip 6 or feedline, 7 SIR in the form of E‐shaped resonator, 8 simplified composite right/left‐handed (SCRLH) resonator 9 placed adjacent to microstrip.…”

“…For these UWB devices to operate interference free, researchers have designed and developed UWB-bandpass filters (BPFs) with integrated multiple stopband characteristics. [2][3][4][5][6][7][8][9][10][11][12][13] Dual passband notches were developed in these UWB filters using stubs acting on the wave cancellation principle, 2,3 slots engraved in the microstrip, 4,5 stepped impedance resonators (SIRs) placed along microstrip 6 or feedline, 7 SIR in the form of E-shaped resonator, 8 simplified composite right/left-handed (SCRLH) resonator 9 placed adjacent to microstrip. Other structures developed dual notches using multiple stubs attached to patch, 10 electromagnetic bandgap structure placed closed to feedline, 11 or combination of stubs with slot 12 or stubs with defected ground structures.…”

Design of compact tri and quad band band-pass filters using stub loaded resonators for wireless applications

“…But the reported works have a narrow bandwidth, large circuit size and high insertion loss for both passbands. Recently, a dual notched band filter response is reported for UWB application with the help of four open stubs which are attached with the microstrip patches in [7]. In [8], a tri-band band-pass filter has been designed using open stubs and DGS.…”