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ALMA Band-1 Receiver. Chau-Ching CHIONG 章朝盛. Institute of Astronomy and Astrophysics, Academia Sinica (ASIAA). Contributions from …. ASIAA Microwave Group: Dr. Y.-J. Hwang, Dr. Y.-F. Kuo, Dr. C.-C. Lin, C.-C. Chuang, C.-T. Ho . Receiver Group: Dr. M.-T. Chen, T.-S. Wei.
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ALMA Band-1 Receiver Chau-Ching CHIONG 章朝盛 Institute of Astronomy and Astrophysics, Academia Sinica (ASIAA)
Contributions from … • ASIAA • Microwave Group: Dr. Y.-J. Hwang, Dr. Y.-F. Kuo, Dr. C.-C. Lin, C.-C. Chuang, C.-T. Ho. • Receiver Group: Dr. M.-T. Chen, T.-S. Wei. • National Taiwan University EE • Prof. H. Wang: Dr. Z.-M. Tsai, Dr. B.-J. Huang, W.-J. Tzeng, Y.-C. Wu, B.-H. Tsai, C.-C. Hung. • National Central University EE • Prof. H.-Y. Chang: S.-H. Weng. • Prof. Y.-S. Lin: Y.-S. Hsieh.
Science of ALMA Band 1 (30-45 GHz) • High resolution Sunyaev-Zel’dovich effect imaging • Anisotropy of cosmic microwave background radiation • High-redshifted CO lines • Probing magnetic field strength via Zeeman measurement
Band-1 Development Plan • International cooperation of Taiwan (ASIAA), Canada (HIA) and Chile (Uni. of Chile). • ASIAA deliver key components, mostly in MMIC technologies (LNA, mixer, filter, IF amp.), while HIA focuses on optics, LNA (hybrid) and system integration. • Proto-type receiver will be assembling in Chile. HIA Band-1 cartridge layout • Main challenges: • Longest wavelength, thus largest component size. • LNA Noise < 7 K. • More than 60 copies required.
Band 1 System Requirements • Observation frequency: 31.3-45 GHz (36%) • Operation mode: single side band (USB), dual linear polarization feed • Image suppression: > 20 dB • Aperture efficiency: > 78 % • IF bandwidth: 4-12 GHz • IF output power: -31 to -18 dBm. IF power variation: 6dB peak-to-peak in any 2GHz BW. 10 dB peak to peak across the complete IF band. • Receiver noise temperature: 17 K (80 % bandwidth) and 28 K (full bandwidth) when operating at 15 K. • LO tuning range: 27.3-33 GHz (18.9%). No mechanical tuning • RMS LO phase noise in jitter: 53 fs (short-term), 17.7 fs (long-term) • LO output power: 10 mW • Front-end cartridge size: diameter 170mm, length ~ 500mm
ALMA Band 1 Front-end System 15K • Optics design + Feedhorn • OrthoMode Transducor (OMT) • Cryogenic Low Noise Amplifier (LNA) • Bandpass Filter + Mixer • Intermediate Frequency (IF) Amplifier • Local Oscillator (LO) + PLL
Reasons for MMIC Approach • Easy integration • High reliability • Mass production (> 200 pcs.) • Low cost (?) • But still high noise. Hybrid X-band LNA from JPL, Weinreb (2007)
Q-band Cascode PHEMT Mixer • The cascode mixer using WIN 0.15 um pHEMT shows • Good conversion gain flatness over 4-12GHz IF frequency. • Low LO power drive. Z.-M. Tsai et. al, EuMIC, 2009
31-45 GHz 0.15 um MHEMT LNA 2f100mm 2-stage mHEMT LNA |S| (dB) Both with 2 mm x 1 mm Vd=2V, Id_dev=37mA, Id_mea=30, 33mA 2f50mm 3-stage mHEMT LNA |S| (dB) December 01-03, 2010 Vd1=Vd2=Vd3=1V, Id1=Id2=Id3=10mA
Cryogenic Measurements Packaging Test Dewar Weng et al., EuMIC, 2011
Balanced LNA as Second Stage • The same design of the 3-stage version. • Better input/output matching. December 01-03, 2010
IF Amplifier Chiong et al., EuMIC, 2009
Integrated LNA-Mixer-Filter-IFA Chip LO Input Bandpass filter (Lin et al. ‘09) IF amplifier LNA cascode HEMT mixer 2nd-stage LNA Total DC power < 150mW • Highly integrated design of the module. • Saving space inside the cryogenic section of the front-end cartridge. • Reducing the possibility of failure in assembling.
YIG-Tuned Oscillator (YTO) in Current ALMA System • Coarse/fine tune • 30 MHz ref. • Excellent phase noise
YTO + Doubler: Phase Noise • Jitter (1 kHz to 1MHz) ~ 45 fs • ALMA spec: 53 fs
VCO Approach • VCO has almost all advantages over YTO except phase noise. • PLL board for YTO has to be modified for VCO operation, because single-tuned VCO has large gain and large gain variation. • Frequency divider is added so that VCO-based PLL can be used in ALMA environment (using 30 MHz reference).
Differential VCO layout Tuning Voltage PN ~ -100 dBc/Hz @ 1MHz offset RF out -0.6 V -2.5 V RF out WIN 0.15 um HBT Total dc power consumption: 85 mW Chiong et al., EuMIC, 2008
Adaptive Loop Bandwidth Technique The VCO gain variation is large. For osc. Freq. > 33GHz, Kvco ~ 200MHz/V, with Filter 1, PLL BW~ 200 kHz. By switching to Filter 2, the PLL BW can be increased from 200kHz to 1MHz. The phase noise can be improved more than 22dB at the offset frequency of 250kHz under such adaptive loop bandwidth. 20
Phase Noise Comparison between Phase-locked YTO and VCO • RMS Jitter/Degree of YTO (@1kHz to 1MHz) is 44.6fs/0.59o • RMS Jitter/Degree of VCO (@1kHz to 1MHz) is 63.8fs/0.77o
YIG vs. VCO • Using adaptive loop bandwidth technique, the whole tuning range of VCO can be locked by single PLL board. • Phase noise within the loop bandwidth (~ 100 kHz) is compatible. • Worse VCO phase noise at larger offset frequency contribute a lot of noise. • Need more advanced InP HBT to meet ALMA spec.
Possible Timeline for Band-1 • 2012: Proposal to ALMA • 2013: Preliminary Design Review. First prototype front-end • 2014: Critical Design Review. Production starts • 2018: Project finishes