Tunable Balanced Bandpass Filter With Constant Bandwidth and High Common-Mode Suppression

Li, Yuan Chun; Xue, Quan

doi:10.1109/tmtt.2011.2161325

Cited by 89 publications

(50 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…7, the voltage and current in the feed line side are expressed as V 1 and I 1 , respectively, whereas V 2 and I 2 stand for the voltage and current in the resonator side, respectively. According to [26] and [27], the external quality factor Q e can be in general expressed as…”

Section: External Coupling Structurementioning

confidence: 99%

Dual-Band High-Temperature Superconducting Bandpass Filter Using Quint-Mode Stub-Loaded Resonators

Song

Wei

et al. 2015

IEEE Trans. Appl. Supercond.

View full text Add to dashboard Cite

Two dual-band high-temperature superconducting (HTS) bandpass filters (BPFs) using quint-mode stub-loaded resonators are presented. The quint-mode resonator is formed by loading four open-circuit stubs in shunt. By properly adjusting the lengths of the resonator, three transmission zeros separate five resonant frequencies into two groups. The first three resonant frequencies form the first passband. The two other frequencies are combined to create the second passband. In addition, a novel approach is proposed to extract the external quality factor Q e based on the group delay of S 21 . A magnetic coupling is introduced to adjust external coupling to meet the desired external Q e . The first filter prototype is initially designed and implemented to verify the theory. Afterward, the second filter is constituted by introducing an additional half-wavelength resonator, resulting to improve the isolation between two desired passbands. Finally, two HTS BPFs are fabricated, and measured results agree well with theory.Index Terms-Bandpass filter (BPF), dual band, external quality factor, high-temperature superconducting (HTS), stub-loaded resonator (SLR).

show abstract

Section: External Coupling Structurementioning

confidence: 99%

Dual-Band High-Temperature Superconducting Bandpass Filter Using Quint-Mode Stub-Loaded Resonators

Song

Wei

et al. 2015

IEEE Trans. Appl. Supercond.

View full text Add to dashboard Cite

show abstract

“…Electronically reconfigurable or tunable microwave circuits are increasingly necessary to control the use of frequency spectrum in modern communication systems . Many kinds of tunable or reconfigurable filters have been explored in the RF circuit design art.…”

Section: Introductionmentioning

confidence: 99%

“…Many kinds of tunable or reconfigurable filters have been explored in the RF circuit design art. In among, varactor‐tuned bandpass filters (BPFs) are widely developed due to the superiorities of small size, fast tuning speed and low cost . Recent literature has focused on constant‐bandwidth filters, but a need remains for topologies with increased frequency‐tuning range.…”

Section: Introductionmentioning

confidence: 99%

Wideband varactor‐tuned balanced bandpass filter with stable passband selectivity

Zhang

Cai

Chen

2018

Int J RF Microw Comput Aided Eng

View full text Add to dashboard Cite

This article presents a wideband tunable balanced bandpass filter (BPF) with stable passband selectivity using optimized varactor‐loaded half‐guided wavelength stepped impedance resonator (SIR). By overall investigation, it can be found that the frequency‐tuning range of the varactor‐loaded SIR is not only controlled by the variation range of the loaded capacitor, but it can be widened by optimizing the SIR. The coupling region between the two coupled SIRs in the proposed BPF is studied for achieving the constant absolute bandwidth (ABW) during the frequency‐tuning process. Meanwhile, the frequency‐dependent source‐to‐load coupling is introduced to realize two self‐adaptive transmission zeros (TZs) on both sides of the tunable differential‐mode (DM) passband so that the proposed filter can keep high selectivity. Benefiting from the constant ABW and two self‐adaptive TZs, the stable DM passband selectivity of the balanced tunable filter can be obtained. For demonstration, a balanced tunable BPF based on the optimized varactor‐loaded SIRs is designed, fabricated and measured. The simulated and measured results, showing good agreement, exhibit a tuning range from 0.542 GHz to 0.926 GHz with 3‐dB constant ABW of around 105 MHz and in‐band insertion loss of 1.5‐2.56 dB.

show abstract

“…The final dimensions of two designs are listed in Table 4.1. For miniaturization purpose, tunable balanced BPFs have been built using structures with reconfigurable passband and stopband [117]- [118]. An analysis based on the external quality factor and inter-stage coupling coefficients are used to investigate the band control in [117], which utilizes half-wavelength resonators loaded with varactors.…”

Section: Experiential Results and Discussionmentioning

confidence: 99%

“…For miniaturization purpose, tunable balanced BPFs have been built using structures with reconfigurable passband and stopband [117]- [118]. An analysis based on the external quality factor and inter-stage coupling coefficients are used to investigate the band control in [117], which utilizes half-wavelength resonators loaded with varactors. A wide differential-mode operating centre frequency range was obtained in [118] with constant fractional bandwidth (FBW) using stepimpedance resonators.…”

Section: Experiential Results and Discussionmentioning

confidence: 99%

Multi-functional and Tunable Microwave Devices and Sub-systems for Wideband Applications

Zhu¹

View full text Add to dashboard Cite

Microwave components and sub-systems have been widely investigated in recent years since they play essential roles in microwave systems. With the rapid development and explosive extension of microwave techniques, high speed, large data volume, and electromagnetic compatibility are not the only issues that concern designers, practitioners, and researchers. Features like multi-functionality, reconfigurability, portability, low energy consumption, miniaturization of circuit size and simple construction have come into focus more and more in recent years. Currently, microwave devices are suffering from several drawbacks: huge losses from a lack of integration of individual components, lack of new functionality, poor adaptability to different environments, low efficiency, flexibility and controllability, high cost and energy consumption, and insufficient miniaturization of circuit size.With these existing challenges and the huge call for innovation in microwave components and subsystems, new design approaches and structures are extremely in demand and a high point of focus.This thesis aims to solve some of the current challenges mentioned above by making four main contributions.The first contribution is the development of new design approaches to design microwave devices with multiple functions to replace cascaded devices with a single function. The main target is to reduce the overall number of components used in constructing microwave systems. With a large number of cascaded devices, huge losses will be produced which decrease systems" reliability and overall performance, not to mention the current large circuit volumes, high cost, and energy consumption. Multi-functional componentry is a suitable and proper solution to solve these problems. In wireless microwave systems, power dividers are usually cascaded with bandpass filters, to get rid of unwanted signals and transmit the desired ones. When the number of output terminations is raised, more filters are required, which makes it more difficult for design and implementation. A four-way power divider integrated with filtering characteristics is proposed to replace the cascaded structures. The proposed design shows equal power division, great selection of filtering signals and reduction in device numbers and overall cost.The second contribution is the development of multiple tunable microwave devices which can be controlled and adapted to different environments. An electrical tuning method is used by loading varactors on microstrip lines. To begin with, tunable bandpass filters were investigated to achieve high tunability of both centre frequency and bandwidth. To that end, several new designs with varactor-loaded coupled-line sections were proposed and verified. Relocatable transmission zero was realised to control the cut-off of the passband at two edges. The concept was applied in the II design of a tunable balanced bandpass filter with a wide tuning range and high common-mode suppression. Wideband power dividers with tunable power division at output termi...

show abstract

Tunable Balanced Bandpass Filter With Constant Bandwidth and High Common-Mode Suppression

Cited by 89 publications

References 14 publications

Dual-Band High-Temperature Superconducting Bandpass Filter Using Quint-Mode Stub-Loaded Resonators

Dual-Band High-Temperature Superconducting Bandpass Filter Using Quint-Mode Stub-Loaded Resonators

Wideband varactor‐tuned balanced bandpass filter with stable passband selectivity

Multi-functional and Tunable Microwave Devices and Sub-systems for Wideband Applications

Contact Info

Product

Resources

About