Compact Dual-Mode DGS Resonators and Filters

Abstract

Abstract-A novel and compact dual-mode defected ground structure (DGS) resonator is presented. Distinct characteristics of the proposed resonator are investigated. Using this type of resonator, a bandpass filter with the center frequency of 2.38 GHz and the fractional bandwidth of 6.7% is simulated and fabricated. The results show that this filter not only has an inherent transmission zero near the passband, but also has a very wide upper stopband with rejection better than 20 dB up to about 12 GHz.

New U-Shaped DGS Bandstop Filters

“…[2] reports the dual-mode DGS resonator and filter, [3] designs a dual-mode bandpass filter which assisted by Ushaped DGS to obtain a improved stopband performance and smaller size, and [4] designed dual-band bandstop filter with the assistance of DGS and stepped impedance resonator. The most reported works on DGS filters are the implementation of low pass filters [5][6][7][8][9] by using new DGS unit [7][8][9] or periodical DGS [10], and the reports on DGS bandstop filters especially the DGS assisted dual-band bandstop filters are very limited.…”

“…In recent years, there is growing interest in defected ground structures (DGS), and many microwave circuits, such as filter [1,2], power divider and power amplifier, etc., have been implemented by using DGS. Similar to the PBG (photonic bandgap) or EBG (electromagnetic bandgap) structure, defected ground structure is formed by etching a defected pattern on the metallic ground plane, which enhances the effective capacitance and inductance of microstrip line, and as a result, DGS has slow-wave characteristics and restrains the spurious responses by rejecting harmonic in microwave circuits, so the performances of filters or other microwave components are effectively improved.…”

Embedded band pass filter designed using embedded capacitor material

“…However, the low dielectric constant of the substrate limits the miniaturization of the filter. To reduce the filter size and cost, much research work has been carried out including developing and utilizing high permittivity embedded functional materials [5], or designing a new structure, such as dual-mode resonator [6,7]. Dual-mode microstrip resonators which are composed of the square loop [8], square patch and loop resonators [9] have been actively reported because each dual-mode resonator can be used as a doubly tuned resonant circuit.…”

A Novel Single and Dual-Band Miniaturized Matched Band-Stop Filter Using Stepped Impedance Resonator

“…It is envisaged that these filters will prove to be crucial, especially onboard aircrafts, and can play a pivotal role in weakening the interference among communication systems, due to the coexisting narrow band applications. To this end, different topologies are proposed and developed in order to realize filters with multiple band-stop responses [10][11][12][13][14][15][16][17][18][19][20][26][27][28][29]. Dual-or multiple-band filters were first presented by Uchida et al in [18].…”

“…It is noted that the advantage of this filter over the conventional broadband band-stop filters is its simple fabrication method and compact size. Wang and Guan in [28] reported compact dual mode DGS resonators and filters, and [29] designed and implemented planar dual-mode and triple-narrowband band-stop filter with independently controlled stop bands and improved spurious response. Generally, although the previous solutions are innovative, dual-or multiple-bands band-stop filter, based on stepped resonators for wireless communication, have not been demonstrated.…”