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| 2. |
- Belitsky, Victor, 1955, et al.
(författare)
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Design and performance of ALMA band 5 receiver cartridge
- 2010
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Ingår i: 35th International Conference on Infrared Millimeter and Terahertz Waves (IRMMW-THz), 2010. - 9781424466559 ; , s. 1-2
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Konferensbidrag (refereegranskat)abstract
- ALMA, Atacama Large Millimetre Array, covers the frequency band from 30 GHz to 960 GHz in ten separate frequency bands. We present here the design and performance of the ALMA Band 5 receiver cartridge that covers 163–211 GHz. The Band 5 receiver shows the state-of-the-art performance with the noise temperature below 65K (SSB) and sideband rejection above 12 dB over 80% of the RF band.
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| 3. |
- Belitsky, Victor, 1955, et al.
(författare)
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Thz-sensor
- 2011
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Annan publikation (övrigt vetenskapligt/konstnärligt)
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| 4. |
- Billade, Bhushan, 1982, et al.
(författare)
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ALMA band 5 cartridge performance
- 2010
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Ingår i: 21st International Symposium on Space Terahertz Technology 2010, ISSTT 2010; Oxford; United Kingdom; 23 March 2010 through 25 March 2010. - 9781617823626 ; , s. 112-
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Konferensbidrag (refereegranskat)abstract
- Work presented here concerns the design and performance of the ALMA Band 5 cold cartridge, one of the 10 frequency channels of ALMA project, a radio interferometer under construction at Atacama Desert in Chile. The Band 5 cartridge is a dual polarization receiver with the polarization separation performed by orthomode transducer (OMT) [1]. For each polarization, Band 5 receiver employs sideband rejection (2SB) scheme based on quadrature layout, with SIS mixers covering 163-211 GHz with 4-8 GHz IF. The LO injection circuitry is integrated with mixer chip and is implemented on the same substrate, resulting in a compact 2SB assembly. Amongst the other ALMA bands, the ALMA Band 5 being the lowest frequency band that uses all cold optics, has the largest mirror. Consequently, ALMA Band 5 mirror along with its support structure leaves very little room for placing OMT, mixers and IF subsystems. The constraints put by the size of cold optics and limited cartridge space, required of us to revise the original 2SB design and adopt a design where all the components like OMT, mixer, IF hybrid, isolators and IF amplifier are directly connected to each other without using any co-ax cables in-between. The IF subsystem uses the space between 4 K and 15 K stage of the cartridge and is thermally connected to 4 K stage. Avoiding co-ax cabling required use of custom designed IF hybrid, furthermore, due to limited cooling capacity at 4 K stage, resistive bias circuitry for the mixers is moved to 15 K stage and the IF hybrid along with an integrated bias-T is implemented using superconducting micro-strip lines. The E-probes for both LO and RF waveguide-to-microstrip transitions are placed perpendicular to the wave direction (back-piece configuration). The RF choke at the end of the probes provides a virtual ground for the RF/LO signal, and the choke is DC grounded to the chassis. The on-chip LO injection is done using a microstrip line directional coupler with slot-line branches in the ground plane. The isolated port of the LO coupler is terminated by floating wideband elliptical termination. The mixer employs two SIS junctions with junction area of 3 μm2 each, in twin junction configuration, followed by a quarter wave transformer to couple it to the signal probe. A quarter-wave high impedance line on an extra layer of SiO2 is used to extract the IF by separating from RF [2]. At the conference, we plan to present details of the cartridge design and results of the experimental characterization of the ALMA Band 5 cold cartridge.
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| 6. |
- Billade, Bhushan, 1982, et al.
(författare)
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Performance of the First ALMA Band 5 Production Cartridge
- 2012
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Ingår i: IEEE Transactions on Terahertz Science and Technology. - 2156-342X .- 2156-3446. ; 2:2, s. 208-214
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Tidskriftsartikel (refereegranskat)abstract
- We present performance of the first ALMA Band 5 production cartridge, covering frequencies from 163 GHz to 211 GHz. ALMA Band 5 is a dual polarization, sideband separation (2SB) receiver based on all Niobium (Nb) Superconductor-Insulator-Superconductor (SIS) tunnel junction mixers, providing 16 GHz of instantaneous RF bandwidth for astronomy observations. The 2SB mixer for each polarization employs a quadrature configuration. The sideband separation occurs at the output of the IF hybrid that has integrated bias-T for biasing the mixers, and is produced using superconducting thin film technology.Experimental verification of the Band 5 cold cartridge performed together with warm cartridge assembly, confirms that the system noise temperature is below 45 K over most of the RF band, which is less than five photon noise (5 hf/k). This is to our knowledge, the best results reported at these frequencies. The measurement of the sideband rejection indicates that the sideband rejection better than 10 dB over 90% of the observational band.
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| 7. |
- Billade, Bhushan, 1982, et al.
(författare)
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Performance of the first ALMA Band 5 production cartridge
- 2011
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Ingår i: Proceedings of the 22nd International Symposium on Space Terahertz Technology, April 26-28th, 2011 - Tucson, Arizona, USA. ; , s. 56-56
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Konferensbidrag (refereegranskat)abstract
- We present performance of the first ALMA Band 5 production cartridge, covering RF frequencies from 163 GHz to 211 GHz. ALMA Band 5 is a dual polarization, sideband separation (2SB) receiver based on all Niobium (Nb) SuperconductorInsulator-Superconductor (SIS) tunnel junction mixer, providing 16 GHz of instantaneous RF bandwidth for the astronomy observations. The 2SB mixer for each polarization employs a quadrature layout. The sideband separation occurs at the output of the IF hybrid that has integrated bias-T for biasing the mixers, and is produced using superconducting thin film technology. Experimental verification of the Band 5 cold cartridge performed together with warm cartridge assembly, confirms the system noise temperature below 45 K, less than five quantum noise (5 hf/k) over most of the RF band, which is to our knowledge, the best results at these frequencies. The measurement of the sideband rejection indicates that the sideband rejection better than 10 dB over 90% of the observational band.
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| 8. |
- Billade, Bhushan, 1982, et al.
(författare)
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Superconducting 4–8 GHz IF Hybrid for Low Noise mm-Wave Sideband Separation SIS Receiver
- 2012
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Ingår i: IEEE Microwave and Wireless Components Letters. - 1558-1764 .- 1531-1309. ; 22:11, s. 589-591
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Tidskriftsartikel (refereegranskat)abstract
- We present the design and performance of a superconducting 90 degree 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.
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| 9. |
- Marouf Rashid, Hawal, 1982, et al.
(författare)
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Design and simulations of a micromachined Golay-cell based THz sensors for room temperature imaging applications
- 2010
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Ingår i: 35th International Conference on Infrared Millimeter and Terahertz Waves (IRMMW-THz) 2010. - 9781424466559 ; , s. 1-2
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Konferensbidrag (refereegranskat)abstract
- A novel broadband THz microsensor for room temperature imaging applications is presented. The sensor's response time is optimized by tuning its structural design, using Monte-Carlo and transient FEM simulations. The optimized and robust sensor shows a 3.5 THz bandwidth (0.5–4THz) and a response time of ~40ms, suitable for real time radio visualization.
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| 10. |
- Marouf Rashid, Hawal, 1982
(författare)
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Improved components for 2SB THz receivers with enhanced sideband rejection performance
- 2013
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The thesis presents work done in improving the sideband rejection ratio for 2SB cryogenic radio astronomy receivers in general, but more specifically, for the future Onsala 20 m 3-mm receiver system and the ALMA Band 5. In order to attain better than 15 dB sideband rejection ratio over the entire bandwidth (approximately 26% RF fractional bandwidth and one octave the IF bandwidth), it is necessary to improve both RF and IF hybrid assembly to optimum performance, i.e. making the hybrids with minimum achievable amplitude and phase imbalance.For this reasons, a 4-8 GHz IF assembly comprising a compact 90° hybrid chip, two bias-Tcircuits and two transmission line circuits was designed and characterised. The compact size of the hybrid chip allows it to be integrated into virtually any sideband separating (2SB)mixer operating at cryogenic temperatures and is furthermore especially advantageous for multi-pixel 2SB receivers or low noise balanced amplifier layouts. The hybrid was fabricated using thin-film technology on Si-substrates and uses air bridges to inter-connect the fingers of the coupler. The hybrid assembly that integrates the bias-T circuit using a MMIC-like approach, where capacitors are integrated on-chip and fabricated using thin-film technology and micro-fabrication. Characterization of the hybrid assembly was performed at a cryogenic temperature of 4 K and sophisticated calibration and fixture de-embedding procedures was used. The measurement result shows that the IF hybrid assembly has state of the art performance, with amplitude and phase imbalance better than 0.5 dB and ± 2° respectively at cryogenic temperatures.In order to allow complete characterization of the ALMA Band 5 cartridge a highly versatile measurement setup has been built. The measurement setup includes all necessary hardwareand achieves automatic measurements for the system noise and sideband rejection with inbuilt optimization procedures. The measurement setup additionally comprises measurementsof the receiver saturation, phase and amplitude stability, as well as optical beam characterization. The performance of the IF hybrid was verified in ALMA Band 5 receiver cartridge using the ALMA Band 5 measurement setup, demonstrating an average sideband rejection ratio of better than 15 dB, i.e. an improvement of 3-9 dB. To further improve the sideband rejection ratio, a novel design for a RF 90° waveguide hybrid was proposed (163-211 GHz). This suggested hybrid employs the multiple branch waveguide design. The specific feature of the proposed hybrid design is the use of controllable ripple in the operational frequency band for achieving better overall amplitude imbalance. This general design approach design could be used for waveguide hybrids at any frequency. Experimental verification of the hybrid shows nearly excellent agreement with the simulations yieldingmeasured amplitude imbalance of 0.15 dB and phase imbalance of ± 2.7° (cf. Fig.5) over most of the band. Such a waveguide hybrid is expected to further improve the sidebandrejection ratio.
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