Superconducting 4-8-GHz Hybrid Assembly for 2SB Cryogenic THz Receivers
Journal article, 2014

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 degrees, 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 degrees. 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.

Directional coupler

microwave components

2SB receiver

thin-film circuits

DIRECTIONAL COUPLERS

superconducting devices

Author

Hawal Marouf Rashid

Chalmers, Earth and Space Sciences, Advanced Receiver Development

Denis Meledin

Chalmers, Earth and Space Sciences, Advanced Receiver Development

Vincent Desmaris

Chalmers, Earth and Space Sciences, Advanced Receiver Development

Alexey Pavolotskiy

Chalmers, Earth and Space Sciences, Advanced Receiver Development

Victor Belitsky

Chalmers, Earth and Space Sciences, Advanced Receiver Development

IEEE Transactions on Terahertz Science and Technology

2156-342X (ISSN)

Vol. 4 2 193-200 6702513

Subject Categories

Atom and Molecular Physics and Optics

DOI

10.1109/tthz.2013.2294761

More information

Created

10/7/2017