Elliptic Function Bandpass Filter Research Articles

Elliptic function compact‐size of the band‐pass filter using complimentary MNZ metamaterial resonator

AbstractIn this article, a new small size of the narrow bandwidth elliptic function band pass filter (BPF) using combination of spur‐line and meander‐line resonator with μ‐near zero (MNZ) metamaterial is presented. The MNZ resonator consists of complimentary structure and the resonator has band‐stop resonant characteristic and positive phase response (+90°) due to its zero‐value permeability. The experimental result for quality factor (Q) of the resonator is 213 at resonant frequency of 9.98 GHz. Also, the BPF is composed of complimentary MNZ resonator and coupling structure. Then, the measurement results for insertion and return losses of a proposed BPF are 1.58 and 15.4 dB with bandwidth of 2.5% at center frequency of 9.96 GHz, respectively. The overall size of the BPF is 5.16 × 5.16 mm2.

Design of Coupled Resonators Bandpass Filter with Defected Ground Structure

In this paper a four-pole elliptic function bandpass filter is designed with two ground slots. A research of microstrip bandpass filters (BPF) using defected ground structures (DGS) is presented. DGS technique allows designs of tight couplings without the necessity of using very narrow coupling gaps. The simulator Sonnet is used to design the resonator and to calculate the coupling coefficient of the basic coupling structure. Compared to similar microstrip filters without defected ground structure, the simulated performances of these novel structures indicate some technological advantages.

A compact bandpass filter using interdigital and step-impedance hairpin resonators

A four-pole elliptic function bandpass filter is designed using miniaturized microstrip interdigital hairpin resonator and step-impedance hairpin resonator. Miniaturization hairpin resonators are realized by using interdigital structure and step-impedance structure having parallel coupled lines. The full-wave simulator IE3D is used to design the compact hairpin resonator and to calculate the coupling coefficient of the basic coupling strictures. The response of the fabricated filters using Al2O3 (er = 9.7, Q × f = 350000 GHz) and 0.6Sm(Co1/2Ti1/2)O3-0.4CaTiO3 (er = 37, Q × f = 43000 GHz) dielectric substrates are designed at a center frequency of 2 GHz. The compact size and the performance of this class of filter have been demonstrated. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1493–1495, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25231

Miniaturization interdigital hairpin microstrip bandpass filter

AbstractA four‐pole elliptic function bandpass filter is designed using compact miniaturized microstrip interdigital hairpin resonator. Miniaturization hairpin resonator is realized by using an interdigital structure having parallel coupled lines. The full‐wave simulator IE3D is used to design the interdigital hairpin resonator and to calculate the coupling coefficient of the basic coupling strictures. The response of the fabricated filters using FR4 substrate is designed at a centre frequency of 1.8 GHz. The compact size and the performance of this class of filter have been demonstrated. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1363–1366, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24314

An Elliptic-Function Bandpass Filter Utilizing Left-Handed Operations of an Inter-Digital Coupled Line

A new elliptic-function bandpass filter (BPF) is proposed, which utilizes an inter-digital coupled line (IDCPL) as a left-handed transmission line. The IDCPL is employed in order to realize a negative coupling between non-adjacent resonators in a wideband BPF. As the authors' knowledge, the left-handed operations of the IDCPL has rarely utilized before, although the IDCPL itself has been widely used in many microwave circuits without being paid attention to the left-handed operations. Measured characteristics of two BPFs are presented in this paper, one is targeted for 3-4GHz WiMAX systems, and the other is for 3-5GHz ultra wideband communication systems (UWB).

Novel Quasi-Elliptic Function Bandpass Filter Using Hexagonal Resonators with Capacitive Loading

A novel and compact elliptic-function bandpass filter is proposed in this letter. The techniques of slot etching and the addition of open stubs are applied to enhance the self-inductance and self-capacitance of hexagonal open-loop resonators. Thus, size reduction and improved transmission performance are obtained. Compared to the performance of the conventional design, the central frequency and insertion loss are reduced by 28% and 3.1 dB, respectively. Measurements show that the proposed filter has a fraction bandwidth of 23% at the central frequency of 1.84 GHz, and its insertion loss in the passband is less than −1.5 dB. The bandpass filter occupies only 12 mm×21.2 mm (approximately 0.24λg×0.14λg).

New microstrip elliptic function bandpass filters using the edge-coupled folded split ring resonators

In this paper, new microstrip cross-coupled elliptic function (CCEF) bandpass filters (BPFs) using folded split-ring resonators (FSRR) are proposed. The CCEF BPFs using these resonators are designed with maintaining a good filter performance and reducing the size significantly. The four-pole and three-pole CCEF BPFs show a 3-dB bandwidth of 3.0% at the center frequency of 2.0 GHz, and insertion losses of 4.28 and 2.77 dB, respectively. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 491–494, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21388

Design of novel cross-coupling elliptic function filters with the miniaturized edge-coupled split ring resonators

In this paper, a new class of cross-coupled planar microwave filters using the microstrip edge-coupled split-ring resonator (EC-SRR) is introduced and its simple equivalent circuit is proposed. The utilization of the microstrip split-ring resonators not only makes the filters compact, but also allows either positive or negative cross coupling to be realized. Also, three-pole and four-pole cross-coupled microstrip elliptic function bandpass filters using the EC-SRR are presented. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 495–499, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20862

New planar dual-mode filters without coupling gaps

A class of new planar dual-mode filters without coupling gaps is proposed. The proposed structures use a single patch wiuhout coupling gaps. Attenuation poles can be implemented on either side of the passband by changing the locations of two feed lines. By cutting two corners in the patch, two attenuation poles on both sides of passband are implemented. A novel dual-mode elliptic-function bandpass filter structure without coupling gaps is also proposed. These new filters can provide a low insertion loss and reduce uncertainty in fabrication owing to the absence of coupling gaps.

Dual-mode elliptic-function bandpass filter usingone single patchresonator without coupling gaps

A novel dual-mode, compact, and simple elliptic-function bandpass filter structure without coupling gaps is proposed. This filter has insertion loss < 1.5 dB and return loss > 10 dB within 2.3–2.375 GHz. Without coupling gaps between the feed lines and the patch resonator, the new filter can provide a low insertion loss and reduce uncertainty in fabrication.

Compact dual-mode elliptic-function bandpass filterusing a single ring resonator with one coupling gap

A novel microwave dual-mode elliptic-function bandpass filter with one coupling gap structure is proposed. This filter has a 4.7% bandwidth at 1.805 GHz with 1.73 dB insertion loss. The filter provides less field perturbation of the ring resonator than conventional filters. Without the output coupling gap between the feed line and the ring resonator, a low insertion loss has been obtained. This compact, high performance filter is useful for mobile and personal communication systems.

A microstrip elliptic function filter with compact miniaturized hairpin resonators

A four-pole elliptic function bandpass filter is designed using compact miniaturized microstrip hairpin resonators. It is shown that the filter occupies a very small area. The full-wave simulator IE3D is used to design the resonator and to calculate the coupling coefficients of the three basic coupling structures. Measurement results are compared with the computed responses.

Compact microwave elliptic function filter usingnovelmicrostrip meander open-loop resonators

A new type of microwave elliptic function bandpass filter using microstrip meander open-loop resonators is proposed. It is shown that the new filter structure is small and allows nonadjacent electric and magnetic couplings to be realised and adjusted. A four-pole filter of this type has, for the first time, been designed and fabricated. The filter is very compact, occupying a circuit size of about a quarter-wavelength by a quarter-wavelength at a midband frequency of 1.47 GHz. Both the simulated and measured results are presented.

Design of bandpass filters using triple‐mode dielectric rod resonators

AbstractMultiply degenerate mode dielectric resonators in which several resonant modes are degenerate in one physical cavity are effective for miniaturizing the bandpass filter (BPF) in the microwave frequencies. In this paper, for a triple‐mode dielectric rod resonator at the resonant frequency of 8.5 GHz at which the TMO1δ mode is degenerate with the dual mode EH11δ, an accurate design is carried out. A three‐stage Chebyshev BPF and six‐stage elliptic function BPF are designed using these resonators. The coupling coefficient between the dielectric resonators via a coupling hole is computed by a rigorous electromagnetic field analysis. The validity of the computed results is confirmed by experiment. As a result, in comparison with the BPF using the conventional triple‐mode cylindrical cavity resonators, the filter volume is reduced to one‐fifth.

Application of Dual TM Modesto Triple- and Quadruple-Mode Filters

The cylindrical cavity dual orthogonal transverse magnetic (TM) mode is introduced as a basic building block for the realization of microwave multiple-coupled-cavity bandpass filters. This concept is shown to offer significant advantages in the design of triple-mode filters and permits the design of the new quadruple-mode filter. Experimental verification is provided by the realization of a triple-mode, six-pole elliptic function bandpass filter with dual TM/sub 110/ and single TE/sub 211/ (transverse electric) modes and a quadruple-mode, eight-pole bandpass filter with dual TM/sub 110/ and dual TE/sub 112/ mode cavities. All units exhibit good agreement between theory and experiment.