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

Abstract

Compact double notch coplanar and microstrip bandstop filters are described. They are based on a version of the open interconnected split ring resonator (OISRR) integrated in microstrip or coplanar waveguides. The OISRR introduces an RLC resonator connected in parallel with the propagating microstrip line. Therefore, this resonator can be modeled as a shunt circuit to ground, with the R, L and C elements connected in series. The consequence for the frequency response of the device is a notch band at the resonant frequency of the RLC shunt circuit. The number of notch bands can be controlled by adding more OISRRs, since each pair of rings can be modeled as a shunt circuit and therefore introduces an additional notch band. In this paper, we demonstrate that these additional rings can be introduced in a concentric way in the same cell, so the size of the device does not increase and a compact multi-notch bandstop response is achieved, with the same number of notch bands as pairs of concentric rings, plus an additional spurious band at a higher frequency.

Computationally-efficient statistical design and yield optimization of resonator-based notch filters using feature-based surrogates

“…On the other hand, microstrip notch filters feature small size, low cost, broad frequency ranges of operation, and overall good performance. Their disadvantages include a limited power handling capability, temperature sensitivity, limited bandwidth, susceptibility to external interference, and tuning difficulty 10 . Recently, complementary metamaterial resonators have been found to offer a promising approach to design microwave notch filters.…”

Dual square split ring enclosed spiral shaped hybrid metamaterial resonator with size miniaturisation for microwave wireless applications

“…An open interconnected split ring resonator was loaded for the compact double notch microstrip bandstop filter. Additional notch band act as a RLC circuit and can be controlled by adding more notch for the different frequency responses 18 . For the precise measurement of the real and imaginary part of the permittivity of the solid dielectric, an advanced investigation was carried out using a modified split ring resonator.…”

Frequency-reconfigurable wideband bandstop filter using varactor-based dual-slotted defected ground structure

“…Bandstop filters (BSFs) [1,2,3,4,5,6] are widely used in microwave and millimeter-wave circuits since they can suppress harmonics, spurious signals and out-of-band noise. In particular, in order to avoid interferences between multiple wireless systems in close proximity, wide-stopband bandpass filters are in high demand [7,8,9].…”