Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

IEEE International Conference on Electron Devices and Solid-State Circuits (EDSSC)

A Superconducting Tunable Filter with Fixed Input/Output Position

Mingchao Li, Kuangyong Gao, Xingkun You, Xiang Li, Huanghao Ying, Huafei Cheng, Haizhen Guo, Zhen Shi, Zhonghai Zhang

Published Jun 13, 2025• 0 citations
Publisher

Abstract

A superconducting tunable filter with fixed inputoutput position was proposed in this letter. The superconducting tunable filter mainly consists of a folded open ring and two tunable capacitors loaded at the open end of the ring. In order to maintain the input/output ports in a fixed position, the input/output resonant cavity adopts a zigzag resonant structure to achieve the adjustment of superconducting input/output position in different frequency bands and ensure the fixed position. A superconducting tunable filter composing of six tunable resonators has been designed, fabricated and measured. The measured results demonstrate the effectiveness of the method described in this article.

DOI
10.1109/edssc64492.2025.11183013

Related papers

Study of mechanically tunable superconducting microwave filter using lumped elements

Shigeki Hontsu, S. Mine, Hiroaki Nishikawa +5 more

We propose a mechanically tunable superconducting microwave filter based on lumped elements composed of planar meander-line inductors (L) and inter-digital capacitors (C). As the first step, we have designed and evaluated a 3-pole Chebyshev bandpass filters with lumped elements using a circuit simulator. It is found that the center frequency, bandwidth and skirt rejection of the filter can be controlled by changing only the capacitance. The L and C elements values are estimated using an electromagnetic simulator. Furthermore, we have fabricated the inter-digital capacitor designed with the above procedure. We have evaluated change of the C values using mechanical tuning as a step toward a tunable superconducting microwave filter.

IEEE Transactions on Applied Superconductivity•Jun 1, 2003•14 citations

Niobium Tunable Microwave Filter

Rizwan Rafique, Thomas Ohki, Peter Linnér +1 more

A superconductor bandpass filter with tunable central frequency in the range of 2-3.5 GHz has been implemented using superconducting quantum interference devices (SQUIDs). The filter is designed using two pi-network resonators connected by a transmission line. Both resonators have a SQUID inductor with a tuning range of 65-200 pH, controlled by current magnetically coupled to the SQUIDs. Over a frequency tunability of 1.5 GHz, the filter has a mid-band insertion loss of 0.5-3.0 dB and corresponding maximum unloaded quality factor of 40. Due to the presence of active elements, tunability of the filter depends on the power of the microwave signal. A maximum power of -52 dBm corresponds to a frequency tuning range of 15%. Spectral measurements by controlling the central frequency of the filter with variable pulsewidth shows that the filter can be tuned at a rate of 120 GHz/mus.

IEEE Transactions on Microwave Theory and Techniques•Apr 15, 2009•9 citations

Compact high-order quint-band superconducting band-pass filter

Di Wu, Bin Wei, Xilong Lu +3 more

In this paper, we present a compact quint-band superconducting filter operating at 2.4, 3.5, 4.7, 5.3, and 5.9 GHz. Matching junctions with different impedance branch lines are used to connect a dual-band sub-filter with a tri-band sub-filter and to reduce the channel interactions. The quint-band filter design is divided into two sections to determine the controllable frequencies and bandwidths, while ensuring compact size and reducing design complexity. The filter is fabricated on double-sided YBCO film deposited on an MgO substrate with a size of 26 mm × 19 mm. The measured results match well with the simulations.

Chinese Physics B•Jun 1, 2018•1 citation

SQUIDs as tunable inductors integrated in the design of filters

Raihan Rafique, Thomas Ohki, Anna Yurievna Herr

This work presents the dc-SQUID based tunable inductance and its relevance into the design of resonators and filters for the qubit application. The SQUID inductance depends on loop inductance, applied magnetic field and bias\ncurrent for a given thermal noise. Tunable resonators and\nfilters have been designed by replacing the inductances of the resonator with a chain of SQUIDs in series. A narrow bandpass filter with variable central frequency is useful for superconducting qubit applications, specifically for improving the line widths of Josephson junction oscillators. We have designed a tunable 3.5 GHz resonator and 2 GHz 7 stage Chebyshev filters to be fabricated in Hypres 4.5 kA/cm2 process. According to simulations, up to 50% of the operating frequency of the designed filter can be varied. We present data that shows a frequency tuning of >2 GHz.

•Jan 1, 2007•0 citations

Cryogenic microwave filter cavity with a tunability greater than 5 GHz

Thomas J. Clark, Vaisakh Vadakkumbatt, Fabien Souris +2 more

A wide variety of applications of microwave cavities, such as measurement and control of superconducting qubits, magnonic resonators, and phase noise filters, would be well served by having a highly tunable microwave resonance. Often this tunability is desired in situ at low temperatures, where one can take advantage of superconducting cavities. To date, such cryogenic tuning while maintaining a high quality factor has been limited to ∼500 MHz. Here we demonstrate a three-dimensional superconducting microwave cavity that shares one wall with a pressurized volume of helium. Upon pressurization of the helium chamber, the microwave cavity is deformed, which results in in situ tuning of its resonant frequency by more than 5 GHz, greater than 60% of the original 8 GHz resonant frequency. The quality factor of the cavity remains approximately constant at ≈7 × 103 over the entire range of tuning. As a demonstration of its usefulness, we implement a tunable cryogenic phase noise filter, which reduces the phase noise of our source by approximately 10 dB above 400 kHz.

arXiv:1810.02404•Review of Scientific Instruments•Nov 1, 2018•16 citations

Tunable Superconducting Cavity using Superconducting Quantum Interference Device Metamaterials

Samuel Kim, David B. Shrekenhamer, K. McElroy +2 more

Abstract Here we consider a tunable superconducting cavity that can be used either as a tunable coupler to a qubit inside the cavity or as a tunable low noise, low temperature, RF filter. Our design consists of an array of radio-frequency superconducting quantum interference devices (rf SQUIDs) inside a superconducting cavity. This forms a tunable metamaterial structure which couples to the cavity through its magnetic plasma frequency. By tuning the resonant frequency of the metamaterial through an applied magnetic flux, one can tune the cavity mode profile. This allows us to detune the cavity initially centered at 5.593 GHz by over 200 MHz. The maximum quality factor approaches that of the empty cavity, which is 4.5 × 106. The metamaterial electromagnetic response is controlled via a low-frequency or dc magnetic flux bias, and we present a control line architecture that is capable of applying sufficient magnetic flux bias with minimal parasitic coupling. Together this design allows for an in-situ tunable cavity which enables low-temperature quantum control applications.

Scientific Reports•Mar 15, 2019•12 citations
A superconducting tunable filter with fixed inputoutput position was proposed in this letter. The superconducting tunable filter mainly consists of a folded open ring and two tunable capacitors loaded at the open end of the ring. In order to maintain the input/output ports in a fixed position, the input/output resonant cavity adopts a zigzag resonant structure to achieve the adjustment of superconducting input/output position in different frequency bands and ensure the fixed position. A superconducting tunable filter composing of six tunable resonators has been designed, fabricated and measured. The measured results demonstrate the effectiveness of the method described in this article.
We propose a mechanically tunable superconducting microwave filter based on lumped elements composed of planar meander-line inductors (L) and inter-digital capacitors (C). As the first step, we have designed and evaluated a 3-pole Chebyshev bandpass filters with lumped elements using a circuit simulator. It is found that the center frequency, bandwidth and skirt rejection of the filter can be controlled by changing only the capacitance. The L and C elements values are estimated using an electromagnetic simulator. Furthermore, we have fabricated the inter-digital capacitor designed with the above procedure. We have evaluated change of the C values using mechanical tuning as a step toward a tunable superconducting microwave filter.
A superconductor bandpass filter with tunable central frequency in the range of 2-3.5 GHz has been implemented using superconducting quantum interference devices (SQUIDs). The filter is designed using two pi-network resonators connected by a transmission line. Both resonators have a SQUID inductor with a tuning range of 65-200 pH, controlled by current magnetically coupled to the SQUIDs. Over a frequency tunability of 1.5 GHz, the filter has a mid-band insertion loss of 0.5-3.0 dB and corresponding maximum unloaded quality factor of 40. Due to the presence of active elements, tunability of the filter depends on the power of the microwave signal. A maximum power of -52 dBm corresponds to a frequency tuning range of 15%. Spectral measurements by controlling the central frequency of the filter with variable pulsewidth shows that the filter can be tuned at a rate of 120 GHz/mus.
In this paper, we present a compact quint-band superconducting filter operating at 2.4, 3.5, 4.7, 5.3, and 5.9 GHz. Matching junctions with different impedance branch lines are used to connect a dual-band sub-filter with a tri-band sub-filter and to reduce the channel interactions. The quint-band filter design is divided into two sections to determine the controllable frequencies and bandwidths, while ensuring compact size and reducing design complexity. The filter is fabricated on double-sided YBCO film deposited on an MgO substrate with a size of 26 mm × 19 mm. The measured results match well with the simulations.
This work presents the dc-SQUID based tunable inductance and its relevance into the design of resonators and filters for the qubit application. The SQUID inductance depends on loop inductance, applied magnetic field and bias\ncurrent for a given thermal noise. Tunable resonators and\nfilters have been designed by replacing the inductances of the resonator with a chain of SQUIDs in series. A narrow bandpass filter with variable central frequency is useful for superconducting qubit applications, specifically for improving the line widths of Josephson junction oscillators. We have designed a tunable 3.5 GHz resonator and 2 GHz 7 stage Chebyshev filters to be fabricated in Hypres 4.5 kA/cm2 process. According to simulations, up to 50% of the operating frequency of the designed filter can be varied. We present data that shows a frequency tuning of >2 GHz.
A wide variety of applications of microwave cavities, such as measurement and control of superconducting qubits, magnonic resonators, and phase noise filters, would be well served by having a highly tunable microwave resonance. Often this tunability is desired in situ at low temperatures, where one can take advantage of superconducting cavities. To date, such cryogenic tuning while maintaining a high quality factor has been limited to ∼500 MHz. Here we demonstrate a three-dimensional superconducting microwave cavity that shares one wall with a pressurized volume of helium. Upon pressurization of the helium chamber, the microwave cavity is deformed, which results in in situ tuning of its resonant frequency by more than 5 GHz, greater than 60% of the original 8 GHz resonant frequency. The quality factor of the cavity remains approximately constant at ≈7 × 103 over the entire range of tuning. As a demonstration of its usefulness, we implement a tunable cryogenic phase noise filter, which reduces the phase noise of our source by approximately 10 dB above 400 kHz.
Abstract Here we consider a tunable superconducting cavity that can be used either as a tunable coupler to a qubit inside the cavity or as a tunable low noise, low temperature, RF filter. Our design consists of an array of radio-frequency superconducting quantum interference devices (rf SQUIDs) inside a superconducting cavity. This forms a tunable metamaterial structure which couples to the cavity through its magnetic plasma frequency. By tuning the resonant frequency of the metamaterial through an applied magnetic flux, one can tune the cavity mode profile. This allows us to detune the cavity initially centered at 5.593 GHz by over 200 MHz. The maximum quality factor approaches that of the empty cavity, which is 4.5 × 106. The metamaterial electromagnetic response is controlled via a low-frequency or dc magnetic flux bias, and we present a control line architecture that is capable of applying sufficient magnetic flux bias with minimal parasitic coupling. Together this design allows for an in-situ tunable cavity which enables low-temperature quantum control applications.