Compact Dual-mode Microstrip Bandpass Filter Based on Greek-cross Fractal Resonator

Abstract

A geometrically symmetrical fractal structure is presented in this paper to provide an alternative approach for the miniaturization design of microstrip bandpass filters (BPFs). The generation process of the geometric geometry is described in detail, and a new fractal resonator called Greek-cross fractal resonator (GCFR) is produced by etching the proposed fractal configuration on the surface of the conventional dual-mode meandered loop resonator. Four microstrip BPFs based on the first four iterations GCFR are modeled and simulated. The simulation results show that with the increase of the number of iterations, the central frequency of the BPF is gradually moving towards the low frequency, which indicates that the proposed fractal resonator has the characteristic of miniaturization. In addition, the parameter optimization and surface current density distribution are also analyzed in order to better understand the performance of the BPF. Finally, a compact dual-mode BPF based on the third iteration GCFR is designed, fabricated and measured. The measurement results are in good agreement with the simulation ones.

Microstrip dual mode multi-bandpass filters based on tree fractal slotted resonator for wireless communication

“…The layout of the second and third level iterations on the slots, results in tri-band filter structures as shown in Figure 11 3 gives the comparison of the proposed work with similar works reported. Not all fractal slotted structures on patches excites higher order modes.In [24] the third iteration Greek-cross fractal sections will give only a single pass band while the proposed work results in tripple pass bands .The increase in iteration level of the tree fractal slot shifts the resonant peaks to the lower frequency side, implies the property of miniaturization which is not obtained in [20], [24] and [27]. The proposed filter exhibits good insertion and return losses in the three pass bands in comparison to the other reported works.…”

“…A left handed multiband metamaterial with tree fractal structure is presented by Xu He-Xiu et al in [21]. Dual mode compact bandpass filters based on patch, ring and semi fractal CSRR structures are reported in [22][23][24][25][26][27].…”

Design of dual-mode SIR bandpass filter based on shorting pin for wireless communication applications

“…A dual mode resonator can be used as a double tuned circuit [9]. Thus, the number of resonators desired is reduced to half for a given degree of filter, which leads to a compact filter setup [10,11].…”

Design and fabrication of a compact microstrip lowpass-bandpass diplexer with high isolation for telecommunication applications

“…In recent years, various resonators with different geometries and structures including open complementary split‐ring resonators (OCSRRs) Ref. , stepped impedance resonator (SIR), coupled‐stub loaded resonator (CSLR), Greek‐cross fractal resonator (GCFR), multimode resonator (MMR), dual‐band resonant junction (DBRJ), meander‐loop and square‐loop resonators, right‐/left‐handed, quintuple‐mode stub‐loaded resonator, and quad‐/penta‐/sext‐mode resonant have been offered to produce compact BPF with good performance. All the LPFs reviewed in the articles above are not tunable.…”

“…In Refs. 15 20,30,31 coupled-stub loaded resonator (CSLR), 21 Greek-cross fractal resonator (GCFR), 22 multimode resonator (MMR), 23,33 dual-band resonant junction (DBRJ), 24 meander-loop and square-loop resonators, 26 right-/left-handed, 28 quintuple-mode stub-loaded resonator, 29 and quad-/penta-/sext-mode resonant 32 have been offered to produce compact BPF with good performance. All the LPFs reviewed in the articles above [6][7][8][9][10][11][12][13][14][15][16][17][18] are not tunable.…”