scholarly journals High-Order Dual-Port Quasi-Absorptive Microstrip Coupled-Line Bandpass Filters

2020 ◽  
Author(s):  
Xiaohu Wu ◽  
Xiaoguang Liu ◽  
Yingsong Li
Keyword(s):  
Transmission Line ◽  
Detailed Analysis ◽  
Bandpass Filters ◽  
Design Concept ◽  
Coupled Line ◽  
Input And Output ◽  
Quarter Wavelength ◽  
Measurement Results ◽  
In Series ◽  
Simultaneous Input

In this article, we present the first demonstration of distributed and symmetrical all-band quasi-absorptive filters that can be designed to arbitrarily high orders. The proposed quasi-absorptive filter consists of a bandpass section (reflective-type coupled-line filter) and absorptive sections (a matched resistor in series with a shorted quarter-wavelength transmission line). Through a detailed analysis, we show that the absorptive sections not only eliminate out-of-band reflections but also determine the passband bandwidth (BW). As such, the bandpass section mainly determines the out-of-band roll-off and the order of the filter can be arbitrarily increased without affecting the filter BW by cascading more bandpass sections. A set of 2.45-GHz one-, two-, and three-pole quasi-absorptive microstrip bandpass filters are designed and measured. The filters show simultaneous input and output absorption across both the passband and the stopband. Measurement results agree very well with the simulation and validate the proposed design concept.

scholarly journals High-Order Dual-Port Quasi-Absorptive Microstrip Coupled-Line Bandpass Filters

2020 ◽  
Author(s):  
Xiaohu Wu ◽  
Xiaoguang Liu ◽  
Yingsong Li
Keyword(s):  
Transmission Line ◽  
Detailed Analysis ◽  
Bandpass Filters ◽  
Design Concept ◽  
Coupled Line ◽  
Input And Output ◽  
Quarter Wavelength ◽  
Measurement Results ◽  
In Series ◽  
Simultaneous Input

In this article, we present the first demonstration of distributed and symmetrical all-band quasi-absorptive filters that can be designed to arbitrarily high orders. The proposed quasi-absorptive filter consists of a bandpass section (reflective-type coupled-line filter) and absorptive sections (a matched resistor in series with a shorted quarter-wavelength transmission line). Through a detailed analysis, we show that the absorptive sections not only eliminate out-of-band reflections but also determine the passband bandwidth (BW). As such, the bandpass section mainly determines the out-of-band roll-off and the order of the filter can be arbitrarily increased without affecting the filter BW by cascading more bandpass sections. A set of 2.45-GHz one-, two-, and three-pole quasi-absorptive microstrip bandpass filters are designed and measured. The filters show simultaneous input and output absorption across both the passband and the stopband. Measurement results agree very well with the simulation and validate the proposed design concept.

scholarly journals Compact Bandstop Filters with Extended Upper Passbands

2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
Majeed A. S. Alkanhal
Keyword(s):  
Transmission Line ◽  
Design Concept ◽  
Size Reduction ◽  
Full Wave ◽  
Filter Structure ◽  
Quarter Wavelength ◽  
Bandstop Filter ◽  
Bandstop Filters ◽  
Line Analysis ◽  
Filter Configuration

This paper presents new compact bandstop filters (BSFs) with extended upper passbands. In the basic proposed filter configuration, the conventional quarter-wavelength open-stub resonators are replaced with equivalent two-section stepped impedance resonators. Transmission line analysis is used to determine the dimensions of the equivalent stepped impedance sections. The filter structure is analyzed using a full wave electromagnetic (EM) simulator and then realized at 2.3 GHz band. Experiments have also been done to validate the performance of the design concept. Compared with the conventional quarter-wavelength-based bandstop filter, significant extensions of the upper passband beyond 9 GHz and 40% size reduction are achieved. Two other variations of the proposed basic BSF with further size reduction (more than 60%) are implemented and their measured performances are verified.

scholarly journals Pseudo-elliptic narrow bandpass filter using shorted coupled-line of higher order design

2019 ◽  
Vol 14 (1) ◽  
pp. 388
Author(s):  
Mohd Nasiruddin Hushim ◽  
Norfishah Ab Wahab ◽  
Muhammad Farid Abdul Khalid ◽  
Tn. Syarifah Atifah Tn. Mat Zin
Keyword(s):  
Bandpass Filter ◽  
Coupled Line ◽  
Transmission Zeros ◽  
Quarter Wavelength ◽  
Measurement Results ◽  
Coupled Lines ◽  
Tan Δ ◽  
Straight Lines ◽  
Good Agreement ◽  
Narrow Bandpass Filter

This paper presents an implementation of quarter wavelength single-shorted coupled-lines for narrow bandpass filter application. It is shown as a new way of creating a single resonance bandpass filter by inter-connected of two <br /> single-shorted quarter wavelength coupled-line sections. By adding more single-shorted coupled-line into the configuration, the form of halfwavelength resonator can increase the degree of order of the filter. For the design of 4<sup>th</sup> order resonator, the coupledlines are arranged inter-connected to each other forming five-fingers lines layout. Due to the interconnection of the coupledlines, transmission zeros appear at the two stopbands which improves the selectivity of the filter response. Investigation on the parametric of the 4<sup>th</sup> order resonator is conducted to observe the controlling parameters and it’s realiability responses of the resonator. For compactness, five-fingers meandered lines is proposed. It is found that the size of the meandered lines resonator was successfully reduced by 33% compared to the five-fingers straight lines resonator of the same order. For validation of concept, the 4<sup>th</sup> order meandered lines resonator was designed at 1 GHz and fabricated on RO3210 microstrip substrate with characteristics given as h = 1.27 mm, Ɛr = 10.2 and tan δ = 3x10<sup>-3</sup>. The measurement results show good agreement with the simulation results.

scholarly journals Inter-connected coupled lines Resonator topology for bandpass filter application

2020 ◽  
Vol 10 (3) ◽  
pp. 2523
Author(s):  
Mohd Nasiruddin Hushim ◽  
Norfishah Ab Wahab ◽  
Tn. Syarifah Atifah Tn. Mat Zin ◽  
Norlia Ghazali
Keyword(s):  
Bandpass Filter ◽  
Higher Order ◽  
Coupled Line ◽  
Microstrip Technology ◽  
Half Wavelength ◽  
Quarter Wavelength ◽  
Coupled Lines ◽  
In Series ◽  
Tan Δ ◽  
Filter Response

This paper presents an inter-connected side-shorted coupled-line resonator topology as a base cell. The base cell is built from two single-shorted quarter-wavelength coupled-line sections, connected in series to give a half-wavelength coupled-line that creates a single resonance of bandpass filter response. Higher-order bandpass filter is produced by adding new single-shorted coupled-line sections, cascaded in an inter-connected manner to the base cell. This new topology creates a unique arrangement that caused cross coupling effects between the resonators, resulting to the occurrence of transmission zeros that lead to the improvement of selectivity of the higher order bandpass filter response. For validation of concept, 2<sup>nd</sup> and 3<sup>rd</sup> order bandpass filters were fabricated using microstrip technology on Roger 3210 substrate with parameter of <em>Ɛr</em> = 10.2, <em>h</em> = 1.27 mm and <em>tan δ</em> = 3x10-3. The filters were measured and the results show good agreement with simulation results.

Ultra-Wideband (UWB) Bandpass Filter Using Multi-Mode SIR

2013 ◽  
Vol 760-762 ◽  
pp. 241-245
Author(s):  
Jian Kang Xiao ◽  
Wu Zhu ◽  
Yong Li ◽  
Wei Zhao
Keyword(s):  
Return Loss ◽  
Bandpass Filter ◽  
Bandpass Filters ◽  
Ultra Wideband ◽  
Input And Output ◽  
Quarter Wavelength ◽  
Coupled Lines ◽  
Multi Mode ◽  
Multiple Transmission

New ultra-wideband (UWB) bandpass filters are proposed by using stepped-impendence resonators (SIRs) and stub-loaded SIRs, aiming at transmitting the signals in the whole UWB passband of 3.1GHz-10.6GHz. Each of the proposed UWB filters consists of two parallel but oppositely arranged compact SIR with tri or quad-section or stub-loaded SIR. In the design, the first two or three resonances of the proposed resonators are properly adjusted to be placed within the UWB. In order to enhance the coupling degree, pairs of quarter-wavelength parallel-coupled lines are longitudinally stretched in both the input and output sides. The UWB bandpass filters behave multiple transmission poles and good return loss of no less than 15dB. A proposed UWB filter is fabricated and measured, and the experiment demonstrates the design.

A Reconfigurable Compact Coupled Line Multiple-Band Bandpass Filter

2013 ◽  
Vol 655-657 ◽  
pp. 1555-1561
Author(s):  
Wen Ko ◽  
Man Long Her ◽  
Ming Wei Hsu ◽  
Yu Lin Wang
Keyword(s):  
Transmission Line ◽  
Bandpass Filter ◽  
Dual Band ◽  
Pass Band ◽  
Coupled Line ◽  
Circuit Structure ◽  
Coupled Lines ◽  
In Series ◽  
Multiple Band ◽  
Triple Band

This study proposes a circuit structure with reconfigurable multiple bands bandpass filter. This circuit can provide a triple-band or dual-band bandpass facility by adjusting two open stubs (L6 and L7) location. The circuit design used three sections of transmission line in series, the two sets of the coupled lines connected to the gap in each transmission line, and two open stubs in the appropriate locations. The design and manufacturing of the circuit structure is innovative and simple. The center frequencies of the triple-band bandpass filter are set at 2.4, 4.2, and 6.5 GHz, respectively, while the center frequencies of the dual-band bandpass filter are the two lower pass band of the triple-band bandpass filter at 2.4 and 4.2GHz. The filters were simulated using the full-wave electromagnetic simulator, IE3D, and measured by Anritsu-37269D. The simulated and measured results show good agreement in the frequency of interest.

scholarly journals Couplinator: A simple computational tool for synthesis of multi-section coupled-line filter based on MPCM-TLM technique

2021 ◽  
pp. 1-10
Author(s):  
E. Faghand ◽  
S. Karimian ◽  
E. Mehrshahi ◽  
N. Karimian
Keyword(s):  
Comparative Analysis ◽  
Transmission Line ◽  
High Frequency ◽  
Computational Tool ◽  
Cad Tools ◽  
Coupled Line ◽  
High Frequency Structure Simulator ◽  
Transmission Line Method ◽  
Set Up ◽  
Planar Circuit

Abstract A new simple computational tool is proposed for the synthesis of multi-section coupled-line filters based on combined modified planar circuit method (MPCM) and transmission line method (TLM) analysis, referred to as MPCM-TLM. Due to its fundamentally simple architecture, the presented tool offers significantly faster optimization of coupled-line filters – for exactly the same initial simulation set-up – than other costly commercially-available tools, giving equally reliable results. Validity and accuracy of the proposed tool have been verified through the design of 3rd, 5th, and 7th order coupled-line filters and comparative analysis between results obtained from the proposed approach and the high-frequency structure simulator. A remarkable 99% time reduction in the analysis is recorded in the case of 7th order filter using the proposed tool, for almost identical results to HFSS. Therefore, it can be confidently claimed that the proposed technique can be used as a reliable alternative to existing complex, costly, processor-intensive CAD tools.

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