Frequency- and Bandwidth-Tunable Absorptive Bandpass Filter

Jeong, Soon Young; Lee, Tae‐Hak; Lee, Juseop

doi:10.1109/tmtt.2019.2914111

Cited by 41 publications

(33 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…That is, the transmission response of the quasi-reflectionless filter is close to the reflection response of its absorptive stub. Note that this relationship is approximate because (13) and (15) are derived under slightly different impedance conditions. As a consequence of the above discussion, the quasi-reflectionless filter's passband BW 3dB is almost identical to the reflection 3-dB bandwidth of its absorptive stub.…”

Section: B a Discussion On The Filter Bandwidthmentioning

confidence: 99%

“…The penalty paid, however, are limited bandwidth, large circuit size, and high insertion loss. Asymmetrical quasi-reflectionless bandapass filter with tunable passband is presented in [15] by using lossy resonator close to one of its termination ports. Reflectionless bandpass filters, particularly those that are well matched at both input and output ports, still remain a challenge to design.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Quasi-Reflectionless Microstrip Bandpass Filters With Improved Passband Flatness and Out-of-band Rejection

Wu¹,

Li²,

Liu³

2020

Preprint

View full text Add to dashboard Cite

High-order quasi-reflectionless bandpass filters with improved passband flatness and good impedance matching both in-band and out-of-band are proposed in this work. The proposed design consists of conventional coupled-lines bandpass sections loaded with the presented absorptive stubs at the input and output. Analysis shows that the absorptive stub is equivalent to a 2-pole bandstop filter. Compared to the prior art, the higher-order nature of the presented absorptive stub enables a flatter passband and better out-of-band rejection. The overall filter stopband attenuation can be readily improved by increasing the number of coupled-lines sections without altering the passband responses. Furthermore, cross-coupling between the two absorptive stubs can be used to improve the out-of-band rejection by introducing two transmission zeros without affecting the absorption characteristics. The proposed design concepts are experimentally validated by the design and fabrication of a set of 2.4-GHz 1-, 2-, and 3-pole microstrip quasi-reflectionless bandpass filters. Measured frequency responses of these filters closely match those of the simulation.

show abstract

Section: B a Discussion On The Filter Bandwidthmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Quasi-Reflectionless Microstrip Bandpass Filters With Improved Passband Flatness and Out-of-band Rejection

Wu¹,

Li²,

Liu³

2020

Preprint

View full text Add to dashboard Cite

show abstract

“…Typically, frequency reconfigurability in filters has been achieved through discretely packaged surface mount components, such as PIN diodes [1], microelectromechanical system (MEMS) [2], and varactors [3]- [7]. However, these kinds of switching components are neither flexible nor low cost.…”

Section: Introductionmentioning

confidence: 99%

Additively Manufactured Dual-Mode Reconfigurable Filter Employing VO₂-Based Switches

Yang

Vaseem

et al. 2020

IEEE Trans. Compon., Packag. Manufact. Technol.

View full text Add to dashboard Cite

Modern wireless devices operate on multiple frequency bands, and thus can benefit from frequency reconfigurable Radio Frequency (RF) components, especially filters as they are typically larger in size and are required for every frequency band. In addition, many applications such as wearable electronics, desire stable performance from the devices when they are bent or flexed. However, most of the reconfigurable filters are built on rigid substrates and utilize expensive discrete RF switches, which need to be soldered to the filters. In this work, we present a fully printed filter that achieves reconfigurability through printed Vanadium Dioxide (VO2) based switches, which are extremely low cost and do not require any soldering for their attachment. The filter design is based on a dual-mode resonator which enables a second-order filter despite a single resonator, thus helping in making the filter compact. It also helps in maintaining a decent insertion loss (2.6 dB), despite relatively low conductivity of the metallic ink. The switches, when activated thermally through a printed heater at the backside, reconfigure the frequency from 4 GHz to 3.75 GHz. The filter has been realized on a flexible Kapton substrate, making the filter conformable to any surface. Measurements under various bending conditions reveal stable performance, making this filter design suitable for a number of wearable and Internet of Things applications.

show abstract

“…At the same time, there are also some papers about tunable filters with constant fractional bandwidth (FBW) . However, there are few fully tunable filters that can tune both BW and frequency . Reference presents a tunable three‐pole 1.5 to 2.2 GHz bandpass filter (BPF) with BW and transmission zero (TZ) control.…”

Section: Introductionmentioning

confidence: 99%

“…Reference uses the SIW structure to tune BW; however, the BW regulation is narrow and can only be used as the BW compensation when tune the resonant frequency. In References , more than two tunable capacitors are used in the resonator for tuning the coupling coefficient; at least one capacitor is directly connected to the ground.…”

Section: Introductionmentioning

confidence: 99%

A fully tunable two‐pole bandpass filter using the resonator with asymmetrical capacitances

Tian

Feng

Xiang

2019

Micro & Optical Tech Letters

View full text Add to dashboard Cite

A fully tunable second-order bandpass filter based on novel resonator is proposed. The resonating frequency and the coupling coefficient between the resonators can be controlled by two varactor diodes. Theoretical expressions have been derived for the coupling coefficient. Four types of filter responses can be reconfigured by setting different bias voltage combinations, including tunable bandwidth filter, constant absolute bandwidth filter, constant fractional bandwidth filter, and decrease bandwidth filter. The simulation and measured results of the four responses are in good agreement with each other, and excellent tunable characteristics are achieved. K E Y W O R D S asymmetrical capacitances, bandpass filter, fully tunable

show abstract

Frequency- and Bandwidth-Tunable Absorptive Bandpass Filter

Cited by 41 publications

References 30 publications

Quasi-Reflectionless Microstrip Bandpass Filters With Improved Passband Flatness and Out-of-band Rejection

Quasi-Reflectionless Microstrip Bandpass Filters With Improved Passband Flatness and Out-of-band Rejection

Additively Manufactured Dual-Mode Reconfigurable Filter Employing VO₂-Based Switches

A fully tunable two‐pole bandpass filter using the resonator with asymmetrical capacitances

Contact Info

Product

Resources

About