Fabrication of Compact Microstrip Line-Based Balun-Bandpass Filter with High Common-Mode Suppression

A new type of balun-bandpass filter was proposed based on the traditional coupled-line theory and folded open-loop ring resonators (OLRRs) configuration. For that, a new device with both filter-type and balun-type characteristics was investigated and fabricated. Both magnetic and electric coupling structures were implemented to provide high performance balun-bandpass responses. The fabricated balun-bandpass filters had a wide bandwidth more than 200 MHz and a low insertion loss less than 2.51 dB at a center frequency of 2.6 GHz. The differences between the two outputs were below 0.4 dB in magnitude and within 180 ± 7° in phase. Also, the balun-bandpass filter presented an excellent common-mode rejection ratio over 25 dB in the passband. An advanced design methodology had been adopted based on EM simulation for making these designed parameters of OLRRs, microstrip lines, and open stubs. The measured frequency responses agreed well with simulated ones.

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Investigation of Compact Balun-Bandpass Filter Using Folded Open-Loop Ring Resonators and Microstrip Lines

Mathematical Problems in Engineering ◽

10.1155/2014/679538 ◽

2014 ◽

Vol 2014 ◽

pp. 1-6 ◽

Cited By ~ 5

Author(s):

Chia-Mao Chen ◽

Shoou-Jinn Chang ◽

Sung-Mao Wu ◽

Yuan-Tai Hsieh ◽

Cheng-Fu Yang

Keyword(s):

Design Methodology ◽

Bandpass Filter ◽

Open Loop ◽

Ring Resonators ◽

Center Frequency ◽

Microstrip Lines ◽

Rejection Ratio ◽

Low Insertion Loss ◽

Em Simulation ◽

Loop Ring

A balun-bandpass filter was proposed by using two folded open-loop ring resonators (OLRRs) to couple three microstrip lines. By tuning the size of the OLRR, the operating frequency of the balun-bandpass filter could be tuned to the needed value. By tuning the size of open stub at the end of microstrip lines, the balanced impedance of the balun-bandpass filter could also be tuned. The fabricated balun-bandpass filter had a wide bandwidth and a low insertion loss at center frequency of the passband. The balun-bandpass filter presented an excellent in-band balanced performance with common-mode rejection ratio more than 20 dB in the passbands. An advanced design methodology had been adopted based on EM simulation for making these designed parameters of OLRRs and microstrip lines. Good correlation was seen between simulation and measurement, and the result was that first run pass had been achieved in the majority of our designs.

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A Compact Tri-Band Bandpass Filter with High Out-of-Band Rejection

Engineering, Technology & Applied Science Research ◽

10.48084/etasr.1209 ◽

2017 ◽

Vol 7 (4) ◽

pp. 1786-1790

Author(s):

M. Abdul-Niby ◽

M. Farhat ◽

M. Nahas ◽

Μ. Μ. Alomari

Keyword(s):

Degrees Of Freedom ◽

Bandpass Filter ◽

Wide Band ◽

Open Loop ◽

Dual Band ◽

Center Frequency ◽

Transmission Zeros ◽

Harmonic Rejection ◽

Band Filter ◽

Loop Ring

This paper presents a planar tri-band bandpass filter with high out-of-band rejection over a wide band. The filter is based on two pairs of λ/4 resonators embedded inside an open loop ring resonator without any size increase, where each pair of resonators are electromagnetically coupled to each other and the feedlines. This results in the excitations of passbands, where the first passband is generated by the open loop resonators. The second and the third passbands are excited by λ/4 resonators. The proposed technique provides sufficient degrees of freedom to control the center frequency and bandwidth of the three passbands independently. In addition, the six transmission zeros created around the passbands results in a tri-band filter with high selectivity, sharp 3 dB cut-off frequency, high isolation, low passband insertion-loss and high out-of-band harmonic rejection across an ultra-broadband frequency range up to 17 GHz. The proposed technique has the ability to switch from triple to dual band by removing one pair of the inner resonators. Design methodology and simulation results of the filter are provided.

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Design of Controllable Dual-Band Bandpass Filter using Open Loop Triangular Ring Resonators Loaded with Stub Coupled with Transmission Line

i-manager’s Journal on Electronics Engineering ◽

10.26634/jele.7.2.11408 ◽

2017 ◽

Vol 7 (2) ◽

pp. 8

Author(s):

Gaurav Yatindra ◽

Chauhan R.K. ◽

◽

Keyword(s):

Transmission Line ◽

Bandpass Filter ◽

Open Loop ◽

Ring Resonators ◽

Dual Band ◽

Triangular Ring

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Design of differential-mode bandpass filter with common-mode suppression using ring dielectric resonator

International Journal of Microwave and Wireless Technologies ◽

10.1017/s1759078716001306 ◽

2016 ◽

Vol 9 (5) ◽

pp. 1029-1035 ◽

Cited By ~ 2

Author(s):

Jugul Kishor ◽

Binod K. Kanaujia ◽

Santanu Dwari ◽

Ashwani Kumar

Keyword(s):

Dielectric Resonator ◽

High Performance ◽

Bandpass Filter ◽

Ring Resonator ◽

Differential Mode ◽

Common Mode ◽

Mode Suppression ◽

Transmission Zeros ◽

System A ◽

Good Agreement

Synthesis of differential-mode bandpass filter (BPF) with good common-mode suppression has been described and demonstrated on the basis of ring dielectric resonator (RDR) for high-performance communication system. A RDR with two pairs of feeding lines has been used to excite TE01δ-mode. This unique combination of feeding lines and the ring resonator creates a differential passband. Meanwhile, TM01δ-mode of the DR can also be excited to achieve common-mode rejection in the stopband. Transmission zeros are created in the lower and upper stopband to further improve the selectivity of the proposed BPF. A second-order differential BPF is designed, fabricated and its performance is measured to validate the concept. There is good agreement between simulated and measured results.

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Miniaturized Wideband Bandpass Filter based on Capacitor-loaded One-eighth Wavelength Coupled Line

Applied Computational Electromagnetics Society ◽

10.47037/2021.aces.j.360707 ◽

2021 ◽

Vol 36 (7) ◽

pp. 865-871

Author(s):

Jin Shi ◽

Jiancheng Dong ◽

Kai Xu ◽

Lingyan Zhang

Keyword(s):

Insertion Loss ◽

Simple Structure ◽

Bandpass Filter ◽

State Of The Art ◽

Center Frequency ◽

Fractional Bandwidth ◽

Coupled Line ◽

Transmission Zeros ◽

Compact Size ◽

Multiple Transmission

A novel miniaturized wideband bandpass filter (BPF) using capacitor-loaded microstrip coupled line is proposed. The capacitors are loaded in parallel and series to the coupled line, which makes the filter just require one one-eighth wavelength coupled line and achieve filtering response with multiple transmission poles (TPs) and transmission zeros (TZs). Compared with the state-of-the-art microstrip wideband BPFs, the proposed filter has the advantages of compact size and simple structure. A prototype centered at 1.47 GHz with the 3-dB fractional bandwidth of 86.5% is demonstrated, which exhibits the compact size of 0.003λ2 g (λg is the guided wavelength at the center frequency) and the minimum insertion loss of 0.37 dB.

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