CDLBand 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

April 19, 2023 1

CDLPeople

• 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

April 19, 2023 2

CDLALMA 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

April 19, 2023 3

CDLBand 2 Proposal: Reviewer Comments

April 19, 2023 4

• All positive• Second-highest ranked proposal (out of 21). Ranked ahead of band 1 • Strong science case, band 2 science workshop good idea

CDLBand 2 Frequency Range

April 19, 2023 5

• Band 3 is 84-116 GHz• Current Band 2 Spec is 67-90 GHz

CDLBand 2 Gain/Noise Budget

April 19, 2023 6

Component/Stage Gain (dB) Noise Temperature (K) TEQ (K) referenced to the input

Lens/Window (297K) -0.16 11.1 11.1IR Filters (15K, 110K) -0.1 2.5 2.6Feedhorn (15K) -0.1 0.35 0.4OMT (15K) -0.1 0.35 0.4Cryogenic LNA (15K) 30 30 33.4Cryogenic Isolator (15K) -1 3.9 insignificantCryogenic Postamp (15K) 25 80 0.1Waveguide Feedthru (297K) -1 77 insignificantDonwnconverter (297K) -15 5000 insignificantWarm IF Amplifier (297K) 20 175 insignificantTotal 57.5 48.0

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)

CDL

April 19, 2023 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.

Milestone Proposed Date Revised Date

Band 2 Science Workshop 02/15/2013 04/15/2013

• AI: Prepare one-page preliminary plan for workshop (date, location, attendees, agenda) [Dave Frayer: 31-July-2012]

CDL

April 19, 2023 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.Milestone Proposed Date Revised Date

Band 2 OMT and horn demonstrated

08/31/2012 10/31/2012

Optics report complete 10/31/2012 12/31/2012

• AI: Prepare drawings and model for OMT [Sri Srikanth: 31-July-2012]

CDLKu-Band (11-18 GHz) OMT

For GBT Pulsar wide band receiverSquare waveguide 0.610” x 0.610”; Rectangular waveguide

0.610” x 0.305”Turnstile junction design for 2:1 aspect ratio waveguideStepped 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”

diameterPrototype for ALMA Band 1 and Band 2 OMT

9April 19, 2023

CDL

April 19, 2023 10

Ku- Band (11-18 GHz) OMT (Microwave Studio Simulations)

CDL

April 19, 2023 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.”

Milestone Proposed Date Revised Date

MMIC LNA delivered to ARO 04/15/2012 Done (05/29/2012)

MIC LNA delivered to ARO 05/31/2012 08/31/2012 (dummy body already delivered)

• AI: Build and test CRYO3 LNA [Marian Pospieszalski: 31-Aug-2012]• AI: Test APRA2 InGaAs MMICs [Eric Bryerton: 31-July-2012]

CDLCryogenic 35nm MMIC LNAs

April 19, 2023 12

CDL

April 19, 2023 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.”

Milestone Proposed Date Revised Date

Prototype band 2 downconverter complete

10/31/2012 12/31/2012

• 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]

CDLBand 2 Block Diagram

April 19, 2023 14

11

0 K

& 1

5 K

IR

Filt

ers

Ort

ho

Mo

de

T

ran

sdu

cer

Win

do

w (

Le

ns?

)

Bia

s F

ilte

r C

ard

Cold Cartridge Assembly 40.02.02 Warm Cartridge Assembly 40.10.02

110 K Stage15 K Stage

HFET Amplifiers

HFET Amplifiers

WR-12 Waveguide

RF: 67 – 94 GHz

LO: 76 – 85 GHz

Amplifier Bias

IF Outputs4 – 12 GHz

DC

Pow

er

Op

tical

Re

fere

nce

S

igna

l

Fir

st L

O

Off

set

Re

fere

nce

M&

C

Lin

es

Pol-0

Pol-1

ICD1

ICD2

ICD3

ICD4

ALMA Band-2 Receiver67 – 94 GHz

Top Level Block DiagramKSS / 2012-01-30

ICD1

ICD2

ICD3

ICD4

ICD5

INTERFACESCold Cartridge Assembly to ALMA Cryostat

Cold Cartridge Assembly to Warm Cartridge Assembly

Cold Cartridge to Bias Module

FE LO to BE Photonics LO

Cold Cartridge Assembly to IF Switch Subsystem

ICD5ICD6

ICD6Warm Cartridge Assembly to Harness Plate

I/O Signals to/from the Receiver(Harness Plate)

FrequencyTripler

AMC

PA

X3

Photo Mixer

Phase Locked Loop

12.6 – 14.2 GHzC

art

rid

ge

Bia

s M

od

ule

4

0.0

4.0

2

LO M&CPower

Amplifier Drain BiasPA

2SB Processor2 Repeats (for Pol-0 & Pol-1)

Pol-0

LO for Pol-1

90o

90o

MC

DP

LL

Warm IF Amplifiers

Pol-1

Pol-0 Pol-1

YTO

USB IF

LSB IF (?)Horn

+Lens?

X2

FrequencyDoubler

CDL

April 19, 2023 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]

CDL

April 19, 2023 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.”

Milestone Proposed Date Revised Date

Modifications to 12m downconverter complete

11/30/2012 01/31/2013

ARO 12m observations using prototype LNAs complete

01/31/2013 03/31/2013

• Does revised schedule make sense?• Actions for next 6-8 weeks?• AI for PM is to get ARO the subaward

CDLAnything Else?

April 19, 2023 17