Band 11 Receiver Development Y. Uzawa on behalf of Band 10 team 2013 July 8 2013 EA ALMA Development Workshop 1
Outline Band 10 status Band 11 specifications and required technologies Preliminary consideration on Band 11 development Summary 2013 July 8 2013 EA ALMA Development Workshop 2
Band 10 Cartridges WG SIS mixer for pol. 0 4 K stage 15 K stage WG SIS mixer for pol. 1 110 K stage 300 K plate More than 50 cartridges have been produced so far. 2013 July 8 2013 EA ALMA Development Workshop 3
DSB noise temperature (K) Summary of Receiver Sensitivity 400 350 300 Min-to-Max Average Spec 100% Spec 80% 250 200 150 100 800 820 840 860 880 900 920 Additional noise from LO source 2013 July 8 51 cartridges (102 IF outputs) LO frequency (GHz) 2013 EA ALMA Development Workshop 4
PAI #80 PAI #70 PAI #60 PAI #50 Plan(2011.12) Achievement Deadline(2014/3/31) recovery plan Schedule Band 10 Achievement VS Plan Early 2014 PAI #40 PAI #30 PAI #20 PAI #10 PAI #0 2013 July 8 2013 EA ALMA Development Workshop 5
Band 11 Specifications Al Wootten, 2010 2013 July 8 2013 EA ALMA Development Workshop 6
Tasks for Band 11 Optics (Band 10 design feasible) WG horn: to be developed Heterodyne mixer SIS (baseline): to be developed HEB (backup): developed at Univ. of Tokyo IF system (current InP amp. available for SIS) SiGe HBT amp.: to be developed for HEB Local oscillator PA and multiplier: no available in Japan Cartridge prototyping 2013 July 8 2013 EA ALMA Development Workshop 7
Physical optics analysis GRASP analysis and Gaussian beam fitting Simulated by A. Gonzalez Freq (GHz) 868 1300 1500 Gaussicity (%) 99.964 99.968 99.967 w0x (mm) 2.033 1.358 1.177 w0y (mm) 2.033 1.358 1.177 z (Focus position, mm) -0.466-0.490-0.495 Pointing angle X (deg) 0 0 0 Pointing angle Y (deg) 0.975 0.967 0.965 Slight design modification to fix a small phase distortion could yield good optics for Band 11 2013 July 8 2013 EA ALMA Development Workshop 8
Heterodyne Mixer Element l Current Instrumentation: SIS vs HEB DSB noise temperature (K) 1500 1000 500 0 SIS (WG) (QO) HEB (WG) (QO) 0.5 1 1.5 Frequency (THz) Univ. of Tokyo (Collaborator) 20 hf / k B 10 hf / k B 5 hf / k B l SIS: quantum limited sensitivity < 1 THz l HEB: State-of-the-art > 1 THz, frequency dependence weak 2013 July 8 2013 EA ALMA Development Workshop 9
HEBs for ASTE Telescope T. Shiino, et al. (Univ. of Tokyo) 1.5 THz Mixer Mount 1.475 THz Trx= 490 K (~7 hf/kb) IF: 1.0-1.2 GHz, limited by IF circuits 0.8-0.9 THz HEB Mixer 2013 July 8 1.3-1.5 THz HEB Mixer SiGe HBTs may extend the IF band. 2013 EA ALMA Development Workshop 10
SiGe HBTs under Consideration BFU725F (NXP), NESG7030M (RENESAS) Circuit design (based on S. Weinreb, Rev. Sci. Inst., 80, 044702, 2009) 0 0 0 1 2 3 4 5 Frequency (GHz) 2013 July 8 2013 EA ALMA Development Workshop 11 Noise (K) 140 120 100 80 60 40 20 Simulated by T. Kojima Gain @ 300 K Noise @ 300 K Noise @ 4 K?? 35 30 25 20 15 10 Simulation performance @ 300 K To be tested @ 300 & 4 K 5 Gain (db)
Band 11 SIS Mixers SIS junctions Nb//NbN: (Δ 1 +Δ 2 ) ~ 3.6 mev (up to ~1.5 THz) NbN//NbN: 2Δ ~ 5.6 mev (up to ~2.4 THz) Tuning circuits Integrated planar-circuits using normal metals Waveguides (back-short, E-plane tuner) 2013 July 8 2013 EA ALMA Development Workshop 12
SIS Junction Parameters NbN/(AlN or MgO)/NbN junction (NICT, collaborator) Gap voltage: 5.6 mv Specific capacitance: 120 ff/µm 2 ωc J R N product: ~ 5 @ 1.4 THz (20% bandwidth) Required current density: ~74 ka/cm 2 J C = 54 ka/cm 2 NbN/AlN/NbN NbN/MgO/NbN Z. Wang, et al. (1997) A. Kawakami, et al. (2001) 2013 July 8 2013 EA ALMA Development Workshop 13
Planar Tuning Circuit Design All-Al tuning circuit A Tuner Transformer Feed 1.0 Designed by T. Kojima 3 5 0.8 Junction size: 0.6 µmφ J c =75 ka/cm 2 A 5.6 22 Unit: µm Coupling 0.6 0.4 0.2 0.0 1.2 1.3 1.4 1.5 1.6 Frequency (THz) 2013 July 8 2013 EA ALMA Development Workshop 14
Investigation on All-Al Microstrip Open-ended stub SIS junction Investigated by M. Kroug 35-um-long stub Appearance of step RF loss: low enough to make an inductance Position of step voltage Phase velocity: as expected by theory Resonance step at 2.4 mv Feasibility confirmed 2013 July 8 2013 EA ALMA Development Workshop 15
WG Tuning Circuit Design Back-short (old tech.) 83 um 166um 1.0 0.8 Designed by T. Kojima Integrated circuit WG back-short 70 um Coupling 0.6 0.4 70 um Substrate thickness :15 um Dielectric constant: 9.6 WG size :166 um x 83 um (WR-0.6) 0.0 1.2 1.3 1.4 1.5 1.6 Frequency (THz) Worth trying 2013 July 8 2013 EA ALMA Development Workshop 16 0.2 Junction size: 0.2 µm J c =75 ka/cm 2
Noise Budget @ ~1.4 THz Single-ended Receiver Balanced Receiver Operating Temp. [K] Gain [db] Input noise [K] Noise at Rec. Input [K] Input noise [K] Noise at Rec. Input [K] Vacuum window 295 > -0.2 13.9 13.9 13.9 13.9 IR filter 110 > -0.2 5.2 5.4 5.2 5.4 IR filter 15 > -0.2 0.7 0.8 0.7 0.8 Cold optics 4 > -0.2 0.2 0.2 0.2 0.2 Waveguide 4 > -0.4 0.4 0.5 0.4 0.5 LO coupler 4 > -0.5 5 11.6 10-dB couple for single end 3-dB couple for balanced Tuning circuit 4 > -1.2 1.3 2.0 1.3 1.8 Mixer 4 > -5.0 < 134.4 263.6 <134.4 237.3 2 hf/k B Isolator 4 > -1.0 1.0 6.4 1.0 5.8 1 st Amplifier 4 31.0 < 5.0 39.1 5.0 35.1 Room temp. IF 295 24 <1100 5.4 <1100 4.8 Including a cable in 4K-300 K 46 349 306 < specification!! High Tc materials such as Nb 3 (Ge,Si) would improve the performance. 2013 July 8 2013 EA ALMA Development Workshop 17
Nb 3 (Ge,Si) film and junction Ph.D thesis Maximum T C : 23 K!! corresponding to ~ 1.7 THz 2013 July 8 2013 EA ALMA Development Workshop 18
Measured junction gap: 4.7 mev Δ Nb3(Ge,Si) = 4.7 mev - Δ Pb (1.2 mev) = 3.5 mev corresponding to ~ 1.7 THz Interesting material!! 2013 July 8 2013 EA ALMA Development Workshop 19
Advanced Tool for Thin Film and Junction Fabrication - Purchased by SIS device group (T. Noguchi) - Manufacturer: AJA (Massachusetts, USA) - Delivered in October 2012 nitridation chamber sputter chamber loading chamber 2013 July 8 2013 EA ALMA Development Workshop 20
Band 10 status Summary Going well (the production is scheduled to end in early 2014) Band 11 development Feasibility study has been started Optics: WG horn is necessary, based on Band 10 optics SIS: WG NbN mixers are the most likely approach (collaborate with NICT) HEB: IF amp. based on SiGe HBTs will be tested (collaborate with Univ. of Tokyo) Undiscussed issue LO: no available at the moment 2013 July 8 2013 EA ALMA Development Workshop 21