Design and implementation of a novel tri-band bandstop filter based on hexagonal metamaterials split ring resonators

Triple Notches Bandstop Microstrip Filter Based on Archimedean Spiral Electromagnetic Bandgap Structure

“…As shown in Figure 17a,b, f 3 decreases with the increase of L 7 , but f 3 increases with the increase of W 7 . Finally, Table 4 shows the comparison of the proposed filter with other triple notches bandstop microstrip filters [15,17,21,23,[24][25][26][27][28][29]35]. Among them, f1, f2, and f3 represent the central resonance frequencies of the first stopband, the second stopband and the third stopband, MSA1, MSA2, and MSA3 represents the maximum stopband attenuation of the first stopband, the second stopband, and In addition, with the increase of L 7 , the first stopband central frequency f 1 = 3.5 GHz and the second stopband central frequency f 2 = 5.2 GHz, both of which do not change with L 7 and W 7 of the L-shaped defect microstrip structure resonator.…”

“…In [22], the authors proposed a microstrip notch filter based on electromagnetic bandgap structure, which realized a high rejection broadband filter. At present, the realization of UWB tri-notch band-stop filters mainly focuses on the following aspects: a stub loaded resonator [23], square ring short stub loaded resonators [24], a stepped impedance resonator (SIR) [25], a coupled-line sub-loaded shorted stepped impedance resonator (SIR) [26], multiple resonant and defected ground structure [27], hexagonal metamaterials split ring resonators [28], the wave cancellation technique [29], using cascaded and multi-armed methods [30], using controlled coupling of open-loop-ring defected ground structure [31], using the U-resonator and suspended multilayer-technique [32], using the multilayer technique and coupled octagonal defected ground structure [33]. Most methods for designing triple notches bandstop microstrip filters mentioned above are based on a single resonant structure, and the 3 dB bandwidth of the stopband are narrow for filtering narrow-band interference.…”

Compact Double Notch Coplanar and Microstrip Bandstop Filters Using Metamaterial—Inspired Open Ring Resonators

“…Defected ground structures (DGSs) have also been applied to the design of filters [14,15] to introduce additional resonances and to improve their frequency responses. Analogous situations to the design of multi-band BPFs can be described for multi-notch bandstop filters (BSF) [16][17][18][19][20][21][22], which find important applications in the suppression of spurious signals in communication systems. In the case of the BSF, the insertion losses are lower in the passband as compared to their BPF counterparts.…”

“…In this paper, we add new concentric rings to a basic open interconnected split ring resonator (OISRR), to achieve additional notch frequencies, thus resulting in a multi-notch response and a simpler design than those proposed in [16][17][18][19][20][21][22]. The open split ring resonator (OSRR) was firstly studied [23,24] and then modified to include interconnected rings [25,26].…”

“…In [27], an example of a three open interconnected split ring resonator (3OISRR) in microstrip technology is described. This design is modified to implement a multi-notch bandstop filter in coplanar technology, thus showing the ability of this resonator to be applied to different planar technologies unlike the other designs presented in [16][17][18][19][20][21][22]. Moreover, losses omitted in previous works are now taken into account in the proposed equivalent circuit model.…”