Band 2 Design Study Kickoff Meeting

1. Band 2 Design Study Kickoff Meeting • Goals of this meeting • Finish in one hour • Everyone upon leaving knows their role and responsibility and how it fits in with overall band 2 design study • Everyone knows what they’re doing for band 2 in the next 6-8 weeks • Goal of band 2 design study • Proposal to ALMA Board for FY14 start of pre-production band 2 with expanded science case and revised specifications 10 September 2014

2. People • Project Manager: Eric Bryerton • Project Scientist: David Frayer • System Engineering : Kamaljeet Saini • Science: David Frayer, Tony Remijan, Scott Schnee, Lucy Ziurys • Optics: Sri Srikanth • MMIC LNA: Eric Bryerton / Matt Morgan • Hybrid LNA: Marian Pospieszalski • Downconverter: Matt Morgan • High Image-Rejection Option: Kamaljeet Saini • Arizona Radio Observatory: Prof. Lucy Ziurys, Gene Lauria, Bob Freund, George Reiland • ALMA NA Development Program Manager: Bill Randolph 10 September 2014

3. ALMA Development Funding • ALMA Development funding profile for North America (includes design studies, hardware and software upgrades, etc.) • FY12: $1.21M • FY13: $2.16M • FY14: $3.81M • FY15+: $5.54M / year • Current Development Projects • Band 5 (Europe to build cold cartridges, NA to build LOs) • NA to spend $1.67M in FY13 and $1.58M in FY14 • EU to spend ~$16M on cold cartridges, i.e. most of their development money through 2017 • VLBI (Event Horizon Telescope) • East Asia (NAOJ) leading consortium to develop proposal for full production of band 1, with some components (LNAs, OMTs, etc.) from NA • A NA development funding wedge begins to open up in FY14 • Also need to renew UVML SIS funding • Goal is to be ready to write proposal to ADSC and ALMA Board for Band 2 pre-production start in FY14 10 September 2014

4. Band 2 Proposal: Reviewer Comments • All positive • Second-highest ranked proposal (out of 21). Ranked ahead of band 1  • Strong science case, band 2 science workshop good idea 10 September 2014

5. Band 2 Frequency Range • Band 3 is 84-116 GHz • Current Band 2 Spec is 67-90 GHz 10 September 2014

6. Band 2 Gain/Noise Budget Table 2: Preliminary gain and noise budget for the ALMA band 2 receiver. • Current ALMA Band 2 Noise Specification: 30 K SSB over 80% of the RF band and 47 K SSB at any RF frequency in the band, where the RF band is defined as 67-90 GHz. • To meet this spec would require a cold lens and a LNA with 20K noise temperature • Also investigate tradeoff of extending upper band edge to 93.2 GHz (simultaneous observations of [N2D+]/[N2H+] line pair) 10 September 2014

7. Overview of Deliverables • We propose to host an ALMA Band 2 Science Workshop to prepare a complete band 2 science case, including a proposed set of key programs for the first 100 hours of Band 2 observing, to drive a set of observational requirements and realistic technical specifications for the band 2 cartridge production. • AI: Prepare one-page preliminary plan for workshop (date, location, attendees, agenda) [Dave Frayer: 31-July-2012] 10 September 2014

8. Overview of Deliverables • We propose to deliver an optics report containing drawings and simulations of the entire band 2 optics, including expected contributions to receiver noise. We will fabricate and test a band 2 turnstile-junction OMT and feed horn. We will investigate the option of a 15 K lens to reduce the receiver noise. • AI: Prepare drawings and model for OMT [Sri Srikanth: 31-July-2012] 10 September 2014

9. Ku-Band (11-18 GHz) OMT For GBT Pulsar wide band receiver Square waveguide 0.610” x 0.610”; Rectangular waveguide 0.610” x 0.305” Turnstile junction design for 2:1 aspect ratio waveguide Stepped transition height 0.305” —› 0.133” Wall thickness between waveguides = 0.039” E-plane combiner- 2 steps; 0.286”, 0.295”, 0.305” External dimensions 5.975”x4.340” Fits in a circle of 6.250” diameter Prototype for ALMA Band 1 and Band 2 OMT 10 September 2014 9

10. Ku- Band (11-18 GHz) OMT (Microwave Studio Simulations) 10 September 2014

11. Overview of Deliverables “In this design study, we will continue to package and characterize already-designed 35nm MMIC amplifiers over the ALMA band 2 frequency range. We will also build and test a band 2 cryogenic hybrid LNA using 80 nm CRYO3 InP HEMTs.” • AI: Build and test CRYO3 LNA [Marian Pospieszalski: 31-Aug-2012] • AI: Test APRA2 InGaAs MMICs [Eric Bryerton: 31-July-2012] 10 September 2014

12. Cryogenic 35nm MMIC LNAs 10 September 2014

13. Overview of Deliverables “We propose to prototype and test a warm downconverter module (in a LO driver PA form factor) using commercial off-the-shelf MMICs. This module will have two 4-12 GHz IF outputs to interface to the warm IF plate.” • Prototype downconverter module in PA form factor probably beyond design study, sufficient to test COTS MMIC as 2SB mixer? • AI: Procure Hittite HMC-MDB277 mixer MMICs [Matt Morgan: 31-July-2012] 10 September 2014

14. Band 2 Block Diagram 10 September 2014

15. Overview of Deliverables “We propose to investigate the option of a high image-rejection downconverter/LO option, clarifying the scientific benefit and estimating the total cost of implementation.” • Requires laser synthesizer to deliver two references on same fiber simultaneously (one ~76-85 GHz and one ~24 GHz fixed) • Part of unfunded photonics upgrade study • AI: Report on current feasibility of high IR option [Kamaljeet Saini, 31-July-2012] 10 September 2014

16. Overview of Deliverables “We propose to integrate and compare observationally the cryogenic LNA options of an ALMA band 2 receiver on the ARO 12m telescope.” • Does revised schedule make sense? • Actions for next 6-8 weeks? • AI for PM is to get ARO the subaward 10 September 2014

17. Anything Else? 10 September 2014