1. WP8: JRA “APRICOT” All Purpose Radio Imaging Cameras on Telescopes Peter Wilkinson: U. Manchester

2. Objectives To develop the design and the sub-system technology for multi-pixel focal-plane “radio cameras” in the range 33-50 GHz (Q-band) To secure state-of-the-art High Electron Mobility Transistors (HEMTs) and Monolithic Microwave Integrated Circuits (MMIC) devices from within Europe. 2FP7 RadioNet Board APRICOT JRA, South Africa 11 November 2011

3. Task 1: Architecture Progress  More thermal modelling & adding experience of building two relevant receivers for the 100-m at Effelsberg. o 2-beam K-band (mainly for spectroscopy) o 2-beam Q-band (mainly for continuum)  Deliverable 8.16 “Comparison of passive chain performance against classical designs ” – main responsibility transferred to INAF-IRA  Milestone 8.04 “Definition paper of functions and interfaces for building blocks”– now drafted 3FP7 RadioNet Board APRICOT JRA, South Africa 11 November 2011

4. Predicted thermal deformation of the horn platelet array 11 November 2011FP7 RadioNet Board APRICOT JRA, South Africa 4 When cooled from 300K to 15K At the corners of the hexagon a deviation of about 2mm is expected which has to be taken into account when fixing the structure to the cryostat vessel.

5. 11 November 2011FP7 RadioNet Board APRICOT JRA, South Africa 5 The demands to the vacuum window are challenging: A test setup with these materials has been measured under real conditions. The window was placed between the 300K environment and a 70K radiation shield under vacuum conditions. The temperature at the inside of the foil/foam window was measured to 236K. This value was basis for the calculations in the next table. Radiation from the vacuum window into the horn block structure

6. Thermal power contributions (assuming 25 horns) 11 November 2011FP7 RadioNet Board APRICOT JRA, South Africa 6 The cooling power needed to keep the system at reasonable temperatures requires the largest cooling machines on the market.

7. Some other issues 11 November 2011FP7 RadioNet Board APRICOT JRA, South Africa 7 DC supply in the dewar: lots of wiring to power & control the LNAs (5 wires per amplifier)  ~250 wires are an infrastructure problem and power dissipation is not good. MPIfR are working on an I 2 C approach to minimise wires. Mass: The table below summarizes the weight of the different parts of a complete 25 pixel receiver camera.

8. Task 2: Passive Components Progress –Platelet array built and tested –Innovative high performance polariser built and tested –Platelet OMT designed and prototype being constructed Deliverable 8.15 – changed –“Designs for very low loss passive components, on low loss substrates” to be replaced “The integration of low-loss passive and active components” (joining together of programmes in Task 2 and Task 3 a better practical step towards a working prototype receiver) 8FP7 RadioNet Board APRICOT JRA, South Africa 11 November 2011

9. 9 7-HORN PLATELET SUMMARY Concept: 45 no glued rings packed together Material: Aluminum Horn mouth diameter: 44mm 7-Horn length: 119mm 7-horn weight: 2.4kg Construction: CNC machine Prototype cost: 5380 € 11 November 2011FP7 RadioNet Board APRICOT JRA, South Africa

10. 10 7-HORN PLATELET Summary of the Performance MULTIHORN; B = 33-50 GHz; BW = 41% SpecificationAchieved Frequency33 GHz41.5 GHz50 GHz33 GHz41.5 GHz50 GHz Nr. of horn77 Edge taper -10 dB@12deg@41.5GHz; G/Tsys optimization for SRT optics -6.2 dB-10.6 dB-18.1 dB S11≤-25 dB ≤-30 dB Crosspolarisation≤-30 dB ≤-28.9 dB≤-32.8 dB≤-30.9 dB SLL≤-20 dB ≤-22 dB ≤-20 dB Horn IsolationBest effort ≤-60 dB Insertion loss≤0.3dB ≤0.1dB HPBW33 “27.1 “24.8 “33 “27.1 “24.8 “ Beam separation68.9 “ 11 November 2011FP7 RadioNet Board APRICOT JRA, South Africa

11. 11 POLARISER SUMMARY Concept: single device iris polariser Material: copper (golden inside) Diameter: 10 mm Length: 107 mm Weight: 50gr Construction: Electroforming Prototype cost: 4100 € POLARISER; B = 33-50 GHz; BW = 41% SpecificationAchieved S 11 ≤-35 dB≤-30 dB S 21 ≤ 0.1dB≤ 0.15dB Phase Unbalance   2 o  2.5 o Crosspolarisation≤-35 dB ≤-33 dB Ampl. Unbalance ≤ 0.05dB Summary of the performance - the best achieved anywhere across such a wide (>40%) band 11 November 2011FP7 RadioNet Board APRICOT JRA, South Africa

12. 12 OMT PLATELET SUMMARY Concept: 1 platelet repeatable turnstile OMT Material: Aluminum 7-OMT diameter: 150 mm 7-OMT heigth: 47 mm 7-OMT weight: 1.6kg Construction: CNC machine (flanges); chemical erosion (sheets) Prototype cost: TBD Expandable OMTs array 11 November 2011FP7 RadioNet Board APRICOT JRA, South Africa

13. 13 OMT PLATELET - Simulation Design Specification: -Return loss:  -20dB -Insertion loss:  0.3dB -Isolation:  -50dB -deliver the two outputs parallel each other, parallel to the omt axis and possibly, symmetrical with respect to the common port axis 11 November 2011FP7 RadioNet Board APRICOT JRA, South Africa

14. 14 Extension of Passive Concepts – deliverable 8.15 Q band Front End Module (Q-FEM) 1)Each OMT has to be connected to LNA input: Waveguide to microstrip transition 2) A Noise Cal signal has to be injected to each receiver chain: Noise diode integration: No Cal distribution. INTEGRATION OF ACTIVE DEVICES TO PASSIVES Q-FEM 7-OMT 11 November 2011FP7 RadioNet Board APRICOT JRA, South Africa

15. 15 Q-FEM module – aspect of deliverable 8.15 SUMMARY Concept: integration of many functions Noise Cal: one diode per horn, no distribution Injection method: twin directional coupler Connection to OMTs: ridged transition Connection among devices: microstrip Mechanics: twisted OMT outputs for coplanar WG inputs Prototype cost: TBD Q-FEM block diagram W-M Diode Coupler Noise Diode room Bias Connectors LNAs Output Connectors Directional Coupler Microstrip W to M Inputs 11 November 2011FP7 RadioNet Board APRICOT JRA, South Africa

16. Task 3: Active Devices FP7 RadioNet Board APRICOT JRA, South Africa 1611 November 2011 Important Matching Efforts Contract between IRAM, MPIfR and IAF before the start of FP7 –assessment of the potential performance of IAF’s mHEMT process at cryogenic temperatures. –extending IAF’s mHEMT device model from room- to cryogenic temperatures using MPIfR’s cryogenic s-parameters probe station Agreements in June 2008 & Sept 2009 between FG-IGN and the University of Cantabria (UC) and IAF –IGN is funding B. Aja (UC) to work at IAF on MMIC designs. –FG-IGN gets access to space in IAF multi-project wafers to implement MMIC designs of interest for FG-IGN.

17. Comparisons now available 11 November 2011FP7 RadioNet Board APRICOT JRA, South Africa 17 FP5 FARADAY: NGST MMIC packaged into LNA NGST 100nm InP from FARADAY project measured at 15K physical: T LNA 40K at 33 GHz reducing to 25K at 50 GHz. Average value is ~30K. T LNA of the packaged InP MMIC reduces by a factor 7 from RT (T LNA ~200K) to 15K (T LNA ~30K Cryogenic optimisation with IAF: design via IGN ; measurements MPIfR Very recent mHEMT MMIC using IAF cryo-optimised technology with 50nm technology. T LNA 25K-60K going the other way to the NGST MMIC Gain is ~25 dB – perhaps could be higher? Initial conclusion: average T LNA is close to the NGST InP technology

18. Q band LNA: IAF MMICs (Beatriz Aja IGN) DesignRun / Technology StatusMeasurementsComments V1 - coplanar733c / 50 nm 9 units in Yebes 2 LNAs finished On wafer LNA RT noise CT measurements pending system calibration V1 - coplanar734a / 100 nm 5 units in YebesOn wafer Error in selection of chips sent, chosen from wrong wafer * V2 - coplanar735Cryo / 50 nm IAFOn wafer V3 - µstrip735Cryo / 50 nm IAF Resonance in ground line V4 - µstrip740 / 50 nm processing V3 redesign without resonance 11 November 201118FP7 RadioNet Board APRICOT JRA, South Africa 50 and 100 nm 31-50 GHz MMICs in Yebes;more finished designs on the way 2× 31-50 GHz LNAs mounted and tested at room temperature

19. Industry standard Molecular Beam Epitaxy facility in UMAN Aim is to maximise performance at cryogenic temperatures – by changing the spacer layer to increase the mobility and keep the conductivity from saturating & hence to stop the T lna flattening off as the T phys reduces (only a factor 7-10 reduction in noise temperature compared with a factor 15 in physical temperature). Novel high breakdown InP pHEMT topology already established and wafers all made Main hurdle has been establishing close cooperation with e-beam partners Task 3: Low-noise transistors

20. e-beam collaborations 11 November 2011FP7 RadioNet Board APRICOT JRA, South Africa 20 IEMN collaboration: First pHEMT transistors fabricated with IEMN Lille’s standard lithography with gate length 130nm (UMAN supplied material and IEMN did lithography). First wafer sent known to have inferior InP substrate. Nevertheless gave results which were reasonable but not competitive with NGST Cryo-4 in the CAY test amplifier at 4-8 GHz. “Good” wafers sent to IEMN – but they have not yet delivered due to unforseen problems with their furnace – now expect delivery in Q4 2011 Glasgow collaboration : Manchester does most of the lithography Glasgow writes the gates Trying 2 and 4 finger architecture and a range of gate widths. At the first iteration in summer 2011 there was a problem with incorrect metal lift-off in Manchester – now redesigning the architecture slightly and learn lesson of metal-lift-off – expect delivery in Q4 2011

21. Challenges Integrated down conversion module - quickly replaceable element Broad-band mixing stage with low power dissipation Multiplier function which allows distribution of a low frequency LO Commercial-off-the-shelf technology, stable and repeatable : OMMIC 70nm metamorphic process Progress: - Chip now delivered and much testing/characterisation completed MMIC down-converter programme

22. Mixer & x8 Multiplier integrated onto the same 3x2mm 2 chip: Task 3 Down converter programme at OMMIC

23. Summary of results 11 November 2011FP7 RadioNet Board APRICOT JRA, South Africa 23 LO section: original LO is injected at 4 GHz – for multiplication up to 32 GHz – chip also has option for injecting LO directly at 32 GHz with external filter. o Performance of sub-sections of circuit have been compared in detail with simulations of a wide range of parameters – looks pretty close in general. Amplifying-mixing section: comparisons of measured performance and simulated performance are again pretty good. o Some difference between isolations LO-RF and LO-IF – explicable in terms of OMMIC wafer run characteristics not being completely as expected (higher gain).

24. Task 4: Establishing accurate performance of LNAs FG-IGN (& INAF) 11 November 2011FP7 RadioNet Board APRICOT JRA, South Africa 24 Progress: C and K band test amplifiers have circulated through 4 labs Slower than hoped progress on Q band cryogenic measurement system

25. Q band LNA: First prototypes (UCan / Yebes) 11 November 2011FP7 RadioNet Board APRICOT JRA, South Africa 25

26. First results of transfer amplifiers YK (20-25 GHz) and YCA (4-8 GHz) LNAs sent to 4 laboratories (MPG, UCan next destinations): –UTVYKNoise & S par.@ 300 K –UManYKNoise & S par.@ 300 K –INAF-IRAYK & YCANoise@ 300 K &15 K –UCanYCANoise @ 44 K 11 November 2011 26 FP7 RadioNet Board APRICOT JRA, South Africa YCA (4-8 GHz)YK (20-25 GHz)

27. First results of transfer amplifiers: K band room temperature noise 27 11 November 2011 FP7 RadioNet Board APRICOT JRA, South Africa

28. First results of transfer amplifiers: K band cryogenic noise 11 November 2011 28 FP7 RadioNet Board APRICOT JRA, South Africa

29. Q band LNA: Noise measurements system 11 November 201129FP7 RadioNet Board APRICOT JRA, South Africa Measurement system still not ready –Delays due to defective noise source (already repaired and recalibrated by Agilent) Pending calibration of lines and components inside the Dewar New cryogenic attenuator –Based on Chalmers designed ATC quartz chip –High fidelity of temperature readings (due to material and design) could simplify measurement system –Commercial alternative not tested at cryogenic temperature

30. Task 5: Simulations etc Challenges –Develop and test algorithms for the subtraction of atmospheric water vapor without spatial switching –Develop and test figures-of-merit to support queue-scheduling of the receiver in both continuum and spectroscopic modes, –To develop the hardware and software architecture for the back-end of an APRICOT cameras. FP7 RadioNet Board APRICOT JRA, South Africa 3011 November 2011

31. Deliverable:Atmospheric model Assumed approach: 1)Hydrodynamical simulations of clouds formation. Numerical determination of time dependent optical depth, and emissivity variations (vs T(z) and wind speed). 2)Reference analytical Kolmogorov-Taylor (K-T) model of atmospheric surface brightness variations due to WV instabilities 3)OCRA-f receiver noise model 4)Scanning strategy model 5)Atmosphere sky field realizations (Beams model and uniform elevation gain model) 6)Atmospheric noise observations with 8-beam OCRA-f system @ TCfA 7)TCfA atmosphere characterization by data fitting via MCMC parameter estimation within combined K-T and receiver models. Calibration of (1) and (2). (Not started) (In progress) (Almost done) (Done) (In progress) Current status:

32. Deliverable: Atmospheric WV subtraction without spatial beam switching Assumed approach: 1)Implementation of various scanning strategies 2)Development of: RT-32 control system / Simulated RT-32 control system to facilitate scanning procedures 3)Scanning strategies tests on RT-32/RT-32 simulator 4)OCRA-f receiver (total power) noise model (noise simulations) 5)Atmospheric model (simulated atmosphere) 6)Optimization of scanning strategies to mitigate atmospheric brightness fluctuations (Not started) (In progress) (Almost done) (In progress) Current status: (Done) (Almost done)

33. Deliverable: Dynamic Queue scheduling strategies Assumed approach: 1)OCRA-f receiver noise model 2)Real-time OCRA-f noise parameter estimation (MCMC maximum likelihood method) 3)Noise estimation processing server 4)Observation alert GUI monitor (Not started) Current status: (Almost done) (In progress)

34. Scanning software

35. Scanning strategies

36. WP8: Deliverables 11 November 2011FP7 RadioNet Board APRICOT JRA, South Africa 36 Numbe r NameProposed Date (months) Forecast date Comments 8.08Euro MICs: advanced technology devices aimed at improved noise performance (Task 3) 24 Q2-2012 8.14 Euro MMICs with improved noise performance (Task 3) 33 Q2-2012 8.16 Comparison of passive chain performance against classical designs (Task 1) 35 Q2-2012 Expect completion of all deliverables in standard period - with exception of three involving realisation of hardware which will use the no cost extension to Q2 2012. Additional work will also continue on Task 5 – matching -funded by TCfA.