Microstrip band-stop filter based on double negative metamaterial

In this work, we present a novel miniature band stop filter based on double negative metamaterial, this circuit is designed on a low-cost substrate FR-4 of relative permittivity 4.4 and low tangential losses 0.002. The proposed filter has a compact and miniature size of 15 mm in length and 12mm in width without the 50 Ω feed lines. The resonator was studied and analyzed with a view to achieving a band-stop behavior around its resonant frequency. The band-stop characteristics are obtained by implementing the metamaterial resonator on the final structure. The obtained results show that this microstrip filter achieves fractional bandwidth of 40% at 2 GHz. Furthermore, excellent transmission quality and good attenuation are achieved. This filter is an adequate solution for global system for mobile communications (GSM).

Dual-Band Bandpass Filter With Controllable Stopband Bandwidth

A novel dual-band bandpass filter (BPF) is proposed with independently controllable transmission zeros (TZs) which can realize widely tunable stopband bandwidth (BW). The planar microstrip filter consists of a three-degree L-C ladder lowpass filter loaded with two unsymmetrical shorted stubs which are used to produce different TZs. By tuning the parameters of the two unsymmetrical shorted stubs, the TZs can be independently controlled. Therefore, the BPF has independent controllable center frequencies (CFs), passband bandwidths, and stopband bandwidths between adjacent passbands. All the L-C values in the equivalent circuit of the proposed filter are optimized to fulfill the design specifications. For demonstration, a dual-band BPF is designed. The measured results show good agreement with the simulated ones.

Microstrip filters Based on Open Stubs and SIR for High Frequency and Ultra-Wideband Applications

This paper includes two new microstrip filter configurations for high frequency and Ultra-Wide Band applications. The first proposed filter is a composition of four parallel open-circuited stubs connected by optimized fractal-structured microstrip line. The filter response is a combination of three passing regions, namely low pass from 0.1 GHz to 3 GHz, band-pass from 4.5 GHz to 9 GHz and high pass from 10.5 GHz to 13 GHz, separated by two rejection regions from 3 GHz to 4.5 GHz and 9 GHz to 10.5 GHz. Deep and sharp rejection regions reaching up to -44.6 dB with 40 % fractional bandwidth (FBW) are observed with a good electrical performance. Furthermore, with a comparative table, the advantages of this proposed BSF in terms of FBW, compactness and insertion loss are compared with recently reported related studies. Secondly a dual-band band pass filter implementing a Stepped-Impedance resonator (SIR) and a modified H-shaped structure is presented. This filter is designed to operate in a low pass region up to 3.58 GHz and a band pass region from 15.38 to 21.65 GHz, with a wide stopband region between 4.46 and 14.07 GHz. The simulated and measured results are in good agreement. Compared to its peers, the compact size and low price allow for a wide application of these filter configurations, while passing frequencies allow operation in the unlicensed frequency spectrum, which is popular for high-speed communication. Keywords: Microstrip Filter, Band Pass, Band Stop, Open Stubs, SIR.

A Compact Bandpass Microstrip Filter for Wireless Communication Applications

A design of Compact Bandpass Microstrip Filter is proposed for wireless communication applications like Bluetooth, Wi-Fi, and 5G. Filter is constructed using parallel-coupled Microstrip lines to form 5th order filter of an inverted C structure. Ground slotted technique is used to enhance the bandwidth with dielectric constant of 9.9. The designed filter is simulated at a center frequency of 5.87GHz and bandwidth of 1.9GHz with an insertion loss of -0.5dB, return loss of greater than 12dB. The proposed filter has a compact size, good increased bandwidth and cost-effective. These results are verified with the theoretically designed values and good agreements are recorded. Hence the proposed compact filter will provide a platform for designing and development of compact filters for the microwave regime.