IEEE Microwave and Wireless Components Letters

Superconducting 4–8 GHz IF Hybrid for Low Noise mm-Wave Sideband Separation SIS Receiver

Bhushan Billade, Hawal Rashid, Vincent Desmaris, Victor Y. Belitsky

Published Oct 16, 2012• 2 citations

Abstract

We present the design and performance of a superconducting 90° hybrid covering a full octave bandwidth from 4 to 8 GHz. The hybrid is designed using the Lange coupler layout. The novel features of this quadrature hybrid include superconducting niobium (Nb) transmission lines, air bridges to connect the fingers of the coupler and a bias-T integrated with the coupler. Our simulations indicate that the amplitude imbalance of the designed hybrid is less than 0.8 dB over the entire 4-8 GHz band with negligible phase imbalance. Experimental verification of the hybrid at 4 K, shows very good agreement between the simulations and the measurement results. The measured amplitude imbalance of the hybrid is less than 0.8 dB over 98% of the band and the maximum phase imbalance is ±4 degrees.

DOI: 10.1109/lmwc.2012.2222363

Related papers

Superconducting 4–8-GHz Hybrid Assembly for 2SB Cryogenic THz Receivers

Hawal Rashid, Denis Meledin, Vincent Desmaris +2 more

We present here the design and characterization of an intermediate frequency (IF) assembly comprising a compact 90° hybrid chip (coupled line coupler - Lange coupler- coupled line coupler), two bias-T circuits for biasing the superconductor-insulator-superconductor (SIS) mixers, and two transmission-line circuits. Specifically, the miniaturized three-section hybrid chip fabricated using thin-film technology utilizes superconducting Niobium (Nb) transmission lines, air bridges to connect the fingers of the Lange coupler (middle section), and is complemented with two bias-T circuits with integrated MIM capacitors. The assembly was designed to ensure amplitude and phase imbalances better than 0.6 dB and ±2°, respectively. Experimental verification of the assembly at 4 K shows good agreement between the measurements and simulations with amplitude imbalance of 0.5 dB and maximum phase imbalance of ±2°. The ALMA band-5 (163-211 GHz) receiver will include such assembly. The receiver tests shows sideband rejection ratio better than 15 dB over the entire RF band, i.e., a systematic improvement of 3-9 dB as compared with the previously reported results.

IEEE Transactions on Terahertz Science and TechnologyJan 31, 201420 citations

Superconducting 4-8 GHz Hybrid Assembly for 2SB Cryogenic THz Receivers

Hawal Rashid, Denis Meledin, Vincent Desmaris +2 more

In the 2SB receivers, the rejection ratio is determined, among other factors, by the performance of the quadrature hybrids. We present here the design and characterization of an intermediate frequency (IF) assembly comprising a compact 90° hybrid chip (coupled line coupler – Lange coupler– coupled line coupler), two bias-T circuits in order to bias the Superconductor-Insulator-Superconductor (SIS) mixers. Specifically, the miniaturized 3-section hybrid chip made using thin-film technology utilizes superconducting Niobium (Nb) transmission lines and air bridges to connect the fingers of the Lange coupler (middle section). The assembly is complemented with two bias-T circuits with integrated MIM capacitors. The assembly was designed to have the amplitude and phase imbalance better than 0.6 dB and ±2.5° respectively. Experimental verification of the assembly at 4 K shows good agreement between the measurements and simulations with amplitude imbalance of 0.5 dB and maximum phase imbalance of ±2°.

Jan 1, 20131 citation

A 4-20 GHz Superconducting 90deg Hybrid Using Capacitively Loaded Coupled Lines for 2SB Heterodyne Receivers

François Joint, Max Behrens, Denis Meledin +10 more

We report the design and cryogenic characterisation of a broadband superconducting 90deg intermediate-frequency (IF) hybrid covering 4 to 20 GHz for sideband-separating (2SB) heterodyne receivers. The hybrid is implemented in thin-film niobium using capacitively loaded edge coupled transmission lines, avoiding the air-bridge interconnections required in Lange-coupler layouts while retaining a compact superconducting implementation with low loss and good quadrature balance. Cryogenic measurements using Vector Network Analyser (VNA) show amplitude and phase imbalance better than 0.6 dB and 6deg, respectively, across the full band. When used in a 2SB receiver, this level of IF balance is consistent with the observed image-rejection performance in the 10-20 dB range, for the full receiver. The design supports the development of wide-instantaneous-bandwidth 2SB receivers for millimeter and submillimeter observatories, improving spectral grasp for broadband line surveys and high-redshift line searches.

arXiv:2610.24859Oct 17, 20260 citations

A 4–20 GHz Superconducting 90◦ Hybrid Using Capacitively Loaded Coupled Lines for 2SB Heterodyne Receivers

François Joint, Max Behrens, Denis Meledin +10 more

We report the design and cryogenic characterisation of a broadband superconducting 90◦ intermediate-frequency (IF) hybrid covering 4–20 GHz for sideband-separating (2SB) heterodyne receivers. The hybrid is implemented in thin-film niobium using capacitively loaded edge coupled transmission lines, avoiding the air-bridge interconnections required in Lange-coupler layouts while retaining a compact superconducting implementation with low loss and good quadrature balance. Cryogenic measurements using Vector Network Analyser (VNA) show amplitude and phase imbalance better than 0.6 dB and 6◦, respectively, across the full band. When used in a 2SB receiver, this level of IF balance is consistent with the observed image-rejection performance in the 10–20 dB range, for the full receiver. The design supports the development of wide-instantaneous-bandwidth 2SB receivers for millimeter and submillimeter observatories, improving spectral grasp for broadband line surveys and high-redshift line searches.

Jun 11, 20260 citations

A Low-noise Balanced SIS Mixer for the 790-950 GHz Band

Takafumi Kojima, Yasunori FUJII, Yoshinori Uzawa

We have developed a low-noise balanced superconductor-insulator-superconductor (SIS) mixer using a waveguide 3-dB 90-degree hybrid coupler over the radio frequency (RF) range of 790-950 GHz and intermediate frequency range of 4-12 GHz at an operating temperature of 4 K. The RF coupler was carefully designed in regards to machining errors so that the entire amplitude imbalance including the mixer gain became smaller. The fabricated coupler was characterized at both room and cryogenic temperature. The receiver noise temperature of the balanced SIS mixer was below 350 K over the entire frequency band and the local oscillator (LO) noise rejection ratio was estimated to be more than 15 dB. This result is equivalent to state-ofthe-art mixer performance at this frequency range.

TEION KOGAKU (Journal of Cryogenics and Superconductivity Society of Japan)Jan 1, 20142 citations

Low-noise integrated balanced SIS mixer for 787–950 GHz

Yasunori Fujii, Takafumi Kojima, Álvaro González +5 more

Abstract We developed a low-noise, compact, balanced superconductor–insulator–superconductor (SIS) mixer, operating in the 787–950 GHz radio frequency range. A waveguide mixer block was designed to integrate all the key components, such as a radio frequency (RF) 90° hybrid coupler, two identical SIS mixer chips, bias-tees, and an intermediate frequency power-combiner. The RF waveguide 90° hybrid coupler consists of branch lines with wide slots optimized by numerical simulation, for ease of fabrication. The balanced mixer was installed into a cartridge type receiver, originally developed for the Atacama Large Millimeter/submillimeter Array Band 10 (787–950 GHz). The receiver demonstrated double sideband noise temperatures of approximately 200 K for most of the band, without any correction for loss in front of the receiver. The local oscillator noise rejection ratio was estimated to be more than 15 dB within the measured frequency range.

Superconductor Science and TechnologyNov 30, 201613 citations