Slow-wave Bandpass Filter Research Articles

A new compact narrow bandwidth slow-wave band-pass filter with high-Qresonators using μ-near zero metamaterial

In this article, a new compact narrow bandwidth slow- wave band-pass filter (BPF) using combination of stepped impedance resonator-shaped hair-pin, interdigital capacitor, and meander-line reso- nator with m-near zero (MNZ) metamaterial is suggested. The MNZ metamaterial resonator has band-stop resonance and positive phase response (190� ) due to zero-value permeability. The experimental result of the resonator shows the loaded quality factor (QL) of 249 at the reso- nant frequency of 10.0 GHz. Also, the insertion and return losses of the proposed BPF are 1.49 and 15.0 dB with the bandwidth of 4% and cen- ter frequency of 10 GHz, respectively. The size of the proposed BPF is

Miniatured Planar Bandpass Filter Using Coupled Metamaterial Resonators

In this article, new microstrip slow-wave bandpass filters using open loop resonator loaded with inter-digital capacitive fingers is proposed. The filter features not only compact in size, but also exhibits spurious stop-band rejection. Filters of this type with elliptic function and Chebyshev response are demonstrated. There is good agreement between experimental and full-wave electromagnetic (EM) simulation results.

New class of SiGe reduced-size loaded slow wave 60 GHz CPW series/shunt stubs and its applications to the design of slow wave bandpass filters

This paper proposes a practical approach for developing a new class of compact slow-wave coplanar waveguide (CPW) series/shunt stubs, which offer 40% reduction in size relative to a conventional design. It demonstrates that the technique using interdigitated capacitive loading can provide size and cost reductions, while also providing performance enhancements such as better return loss. The experimental prototypes presented in this paper demonstrate the validity of the design method and the ability to print interdigitated capacitors inside the center conductor of the series/shunt stubs. The principle of achieving such high-quality circuits is detailed and is also confirmed by theoretical and experimental results, which are in reasonable agreement up to at least 70 GHz. The paper also presents a family of novel topologies of slow wave bandpass filters based on the proposed capacitively loaded CPW series/shunt stubs.

The design of novel multilayer slow-wave aperture-coupled microstrip bandpass filters

New multilayer aperture-coupling microstrip slow-wave bandpass filters using an open-loop resonator loaded with interdigital capacitive fingers is proposed. The new filter configuration consists of two arrays of microstrip open-loop resonators loaded with four fingers and eight fingers that can be coupled through the apertures on the common ground plane. The filter is not only compact in size, but also exhibits spurious stopband rejection. Filters of this type with elliptic function and Chebyshev response are demonstrated. There is good agreement between the measured and simulated results. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1633–1639, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21715

A 60‐GHz GaAs micromachined slow‐wave bandpass filter using a microstrip stepped‐impedance hairpin resonator

AbstractIn this paper, a new microstrip stepped‐impedance hairpin resonator (SIHR) slow‐wave bandpass filter (BPF) using a dielectric‐supported air‐gapped microstrip line (DAML) via surface micromachining on GaAs substrate is proposed. The slow‐wave periodic structures utilize the parallel‐ and series‐resonance characteristics of the resonators to construct a band‐pass filter. The proposed slow‐wave band‐pass filter is designed to produce a passband of 10% at the fundamental frequency of 60 GHz. It exhibits insertion loss of 2.23 dB, return loss of better than 15 dB, and a stopband greater than 35 dB. This filter is useful for many millimeter‐wave system applications. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 86–89, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21089

A novel superconducting CPW slow‐wave bandpass filter

AbstractA novel slow‐wave half‐wavelength coplanar waveguide (CPW) resonator using high‐Tc superconducting (HTS) films has been studied and used in a new filter topology. The slow‐wave effect is achieved by the capacitively loaded structure with a symmetrical interdigital line loaded on both sides of the central line. The velocity reduction (Vp/c0) of the resonator is about 0.050. A three‐pole Butterworth bandpass filter has been designed and fabricated with the use of the resonator. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 34: 255–259, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10431

Slow-wave bandpass filters using ring or stepped-impedance hairpin resonators

This paper proposes a new class of slow-wave bandpass filters that uses a microstrip line periodically loaded with microstrip ring or stepped-impedance hairpin resonators. The new slow-wave periodic structures utilize the parallel and series resonance characteristics of the resonators to construct a bandpass filter. Unlike conventional slow-wave filters, the proposed bandpass filters are designed to produce a narrow passband at the fundamental mode of the resonators. The new filters provide lower insertion loss than that of parallel- or cross-coupled ring and stepped-impedance hairpin bandpass filters. The calculated frequency responses of the filters agree well with experiments.