A Novel Ultra-Wideband Common-Mode Suppression Circuit Based on Multi-Mode Transmission Line

AbstractIn this paper, a tunable balanced-to-balanced in-phase filtering power divider (FPD) is designed, which can realize a two-way equal power division with high selectivity and isolation. A differential-mode (DM) passband with a steep filtering performance is realized by applying microstrip stub-loaded resonators (SLRs). Meanwhile, six varactors are loaded to the SLRs to achieve the center frequency (CF) and bandwidth adjustment, respectively. U-type microstrip lines integrated with stepped impedance slotline resonators are utilized as the differential feedlines, which suppress the common-mode (CM) intrinsically, making the DM responses independent of the CM ones. A tuning center frequency from 3.2 to 3.75 GHz and a fractional bandwidth (12.1–17.6%) with more than 10 dB return loss and less than 2.3 dB insertion loss can be achieved by changing the voltage across the varactors. A good agreement between the simulated and measured results is observed. To the best of authors' knowledge, the proposed balanced-to-balanced tunable FPD is first ever reported.

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Design and analysis of a planar UWB bandpass filter with stopband characteristics using MMR technique

International Journal of Microwave and Wireless Technologies ◽

10.1017/s1759078720001762 ◽

2021 ◽

pp. 1-8

Author(s):

Gaurav Saxena ◽

Priyanka Jain ◽

Y. K. Awasthi

Keyword(s):

Return Loss ◽

Group Delay ◽

Bandpass Filter ◽

Ground Plane ◽

Cost Effective ◽

Ultra Wideband ◽

Defected Ground Structures ◽

Ground Structures ◽

Multi Mode ◽

Mode Resonator

Abstract In this paper, a ultra-wideband (UWB) bandpass filter with stopband characteristics is presented using a multi-mode resonator (MMR) technique. An MMR is formed by loading three dumbbell-shaped (Mickey and circular) shunt stubs placed in the center and two symmetrical locations from ports, respectively. Three circular and arrowhead defected ground structures on the ground plane are introduced to achieve UWB bandwidth with a better roll-off rate. The proposed filter exhibits stopband characteristics from 10.8 to 20 GHz with a 0.4 dB return loss. The group delay and roll-off rate of the designed filter are <0.30 ns in the passband and 16 dB/GHz at lower and higher cut-off frequencies, respectively. The dimension of the filter is 0.74λg × 0.67λg mm2 and was fabricated on a cost-effective substrate. All simulated results are verified through the experimental results.

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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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