Band 11 Receiver Development

Transcription

1 Band 11 Receiver Development Y. Uzawa on behalf of Band 10 team 2013 July EA ALMA Development Workshop 1

2 Outline Band 10 status Band 11 specifications and required technologies Preliminary consideration on Band 11 development Summary 2013 July EA ALMA Development Workshop 2

3 Band 10 Cartridges WG SIS mixer for pol. 0 4 K stage 15 K stage WG SIS mixer for pol K stage 300 K plate More than 50 cartridges have been produced so far July EA ALMA Development Workshop 3

4 DSB noise temperature (K) Summary of Receiver Sensitivity Min-to-Max Average Spec 100% Spec 80% Additional noise from LO source 2013 July 8 51 cartridges (102 IF outputs) LO frequency (GHz) 2013 EA ALMA Development Workshop 4

5 PAI #80 PAI #70 PAI #60 PAI #50 Plan( ) Achievement Deadline(2014/3/31) recovery plan Schedule Band 10 Achievement VS Plan Early 2014 PAI #40 PAI #30 PAI #20 PAI #10 PAI # July EA ALMA Development Workshop 5

6 Band 11 Specifications Al Wootten, July EA ALMA Development Workshop 6

7 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 EA ALMA Development Workshop 7

8 Physical optics analysis GRASP analysis and Gaussian beam fitting Simulated by A. Gonzalez Freq (GHz) Gaussicity (%) w0x (mm) w0y (mm) z (Focus position, mm) Pointing angle X (deg) Pointing angle Y (deg) Slight design modification to fix a small phase distortion could yield good optics for Band July EA ALMA Development Workshop 8

9 Heterodyne Mixer Element l Current Instrumentation: SIS vs HEB DSB noise temperature (K) SIS (WG) (QO) HEB (WG) (QO) 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 EA ALMA Development Workshop 9

10 HEBs for ASTE Telescope T. Shiino, et al. (Univ. of Tokyo) 1.5 THz Mixer Mount THz Trx= 490 K (~7 hf/kb) IF: GHz, limited by IF circuits THz HEB Mixer 2013 July THz HEB Mixer SiGe HBTs may extend the IF band EA ALMA Development Workshop 10

11 SiGe HBTs under Consideration BFU725F (NXP), NESG7030M (RENESAS) Circuit design (based on S. Weinreb, Rev. Sci. Inst., 80, , 2009) Frequency (GHz) 2013 July EA ALMA Development Workshop 11 Noise (K) Simulated by T. Kojima 300 K 300 K 4 K?? Simulation 300 K To be 300 & 4 K 5 Gain (db)

12 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 EA ALMA Development Workshop 12

13 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: ~ 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 EA ALMA Development Workshop 13

14 Planar Tuning Circuit Design All-Al tuning circuit A Tuner Transformer Feed 1.0 Designed by T. Kojima Junction size: 0.6 µmφ J c =75 ka/cm 2 A Unit: µm Coupling Frequency (THz) 2013 July EA ALMA Development Workshop 14

15 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 EA ALMA Development Workshop 15

16 WG Tuning Circuit Design Back-short (old tech.) 83 um 166um Designed by T. Kojima Integrated circuit WG back-short 70 um Coupling um Substrate thickness :15 um Dielectric constant: 9.6 WG size :166 um x 83 um (WR-0.6) Frequency (THz) Worth trying 2013 July EA ALMA Development Workshop Junction size: 0.2 µm J c =75 ka/cm 2

17 Noise ~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 > IR filter 110 > IR filter 15 > Cold optics 4 > Waveguide 4 > LO coupler 4 > dB couple for single end 3-dB couple for balanced Tuning circuit 4 > Mixer 4 > -5.0 < < hf/k B Isolator 4 > st Amplifier < Room temp. IF < < Including a cable in 4K-300 K < specification!! High Tc materials such as Nb 3 (Ge,Si) would improve the performance July EA ALMA Development Workshop 17

18 Nb 3 (Ge,Si) film and junction Ph.D thesis Maximum T C : 23 K!! corresponding to ~ 1.7 THz 2013 July EA ALMA Development Workshop 18

19 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 EA ALMA Development Workshop 19

20 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 EA ALMA Development Workshop 20

21 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 EA ALMA Development Workshop 21