KFPA Noise Calibration Module (NCM)Eric Bryerton – NRAO CDL

Bethe Coupler

DC5-pinFrom OMT

To Isolators

Item Specification Verification Method / Notes on Compliance

RF In/Out WR-42, UG595/U Flange Equivalent By design. See KFPA NCM chassis drawing.

RF Channel Isolation 40dB minimum By simulation [see Fig. 4]. Level too low to be measured accurately.

Equivalent Injected Noise 1.5-6.0K Unit testing. Unit #1 was non-compliant below 18.5 GHz, see Figs. 10-12, when constant bias is applied across the entire band. If bias is adjusted, injected noise can be tuned to be between 1.5-6.0K over any 2 GHz bandwidth.

Dissipated Power 15mW maximum Unit testing. Single-pixel unit was compliant, see Section 4.

Response Time 100us max rise/fall By design. Test block testing [1] showed response time limited by bias supply. RC time constants of bias circuits, both on and off MMIC, are significantly less than this time.

Stability +/-3% over 4 hours Testing of test block [1].

NOT CAL TTL Low -> Injected Noise ON By design. See Monitor and Control interface specification in section 2.

KFPA-7 NCM Compliance Matrix

KFPA NCM

MMIC LNA:UMS CHA2092b

P1

P4

P6

P2

P3

P5

6-Port Bethe Coupler

P1: noise sourceP2: load for uncoupled noise cal powerP4->P3, P6->P5: main signal path (OMT->isolator)

6-Port Bethe Coupler

Coupling = -25 +/- 1 dB

6-Port Bethe Coupler

Input Return Loss > 30dB

6-Port Bethe Coupler

Directivity > 20dB (S31/S41)Channel-to-Channel Isolation > 50dB

KFPA Noise Calibration Module #1S-parameter Measurements

KFPA Noise Coupler Module

-60

-50

-40

-30

-20

-10

0

16 18 20 22 24 26 28

Frequency (GHz)

|S1

1|

(dB

)

CH A

CH B

Load

KFPA Noise Coupler Module

-0.5

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0.5

16 18 20 22 24 26 28

Frequency (GHz)

|S21

| (d

B)

CH A

CH B

KFPA Noise Calibration Module #1Noise Measurements

297K / 77KLoad

LNA(T=25.3K)

Noise Cal Module(T=33.0K)

Downconverter + Detector

T=14.0K

KFPA Noise Calibration Module #1Noise Measurements

KFPA Noise Cal Module #1(Vds=0.71V, Vgs=-0.53V, Ids=6mA)

0

5

10

15

20

25

30

18 20 22 24 26

Frequency (GHz)

Rec

eive

r N

ois

e (K

)

Noise Cal OFF

Noise Cal ON

KFPA Noise Cal Module #1(Noise Cal ON - Noise Cal OFF)

0

1

2

3

4

5

6

7

8

18 19 20 21 22 23 24 25 26Frequency (GHz)

No

ise

Cal

(K

)

VDS=0.71V, VGS=-0.53V, IDS=6mA

KFPA LCP

0

1

2

3

4

5

6

7

8

9

10

18 20 22 24 26 28

Frequency (GHz)

Tca

l (K

)

LO1=25.8 GHz

LO1=29.3 GHz

LO1=31.8 GHz

LO1=33.3 GHz

VDS = 0.667V

KFPA-1 Laboratory Tcal Measurements

KFPA RCP

0

1

2

3

4

5

6

7

8

9

10

18 20 22 24 26 28

Frequency (GHz)

Tca

l (K

)

LO1=25.8 GHz

LO1=29.3 GHz

LO1=31.8 GHz

LO1=33.3 GHz

KFPA-1 Laboratory Tcal Measurements

Measured Tcal of Current GBT K-Band Receiver vs. KFPA

0

1

2

3

4

5

6

7

8

9

10

18 19 20 21 22 23 24 25 26

Frequency (GHz)

Tca

l (K

)

RCP1LCP1RCP2LCP2KFPAPoly. (KFPA)

The standard deviation of the difference between the actual measurement and 4th degree polynomial fit is 7.5% of the measured value

0

2

4

6

8

10

12

14

16

18

20

18 19 20 21 22 23 24 25 26

Frequency (GHz)

Tca

l (K

)

9/25/2008

9/26/2008

10/28/2008

9/4/2008

Between 9/4/08 and 9/25/08, NCM VDS bias was increased.

KFPA-1 Laboratory Tcal Measurements

Noise Cal Test Block Measurements

UMS2092b LNA (thru 20dB atten and KM-117 LNA)

0

500

1000

1500

2000

2500

3000

3500

4000

18 19 20 21 22 23 24 25 26

Frequency (GHz)

T(O

N)-

T(O

FF

) (K

)

Vgs=-0.55V

Vgs=-0.54V

Vgs=-0.53V

8mA

10mA

11mA

VDS=0.85V -> PDC=6.8mW for bottom trace

31-Jan-09 CDR approval, production can begin13-Mar-09 NCM blocks machined (using NRAO-CV machine shop)27-Mar-09 NCM blocks plated17-Apr-09 Units 1-3 assembled8-May-09 Testing of units 1-3 complete; deliver units 1-38-May-09 Units 4-5 assembled22-May-09 Testing of units 4-5 complete; deliver units 4-522-May-09 Units 6-7 assembled5-June-09 Testing of units 6-7 complete; deliver units 6-7

KFPA-7 NCM Production Schedule

Item Specification Verification Method / Notes on Compliance

RF In/Out WR-42, UG595/U Flange Equivalent By design. See KFPA NCM chassis drawing.

RF Channel Isolation 40dB minimum By simulation [see Fig. 4]. Level too low to be measured accurately.

Equivalent Injected Noise 1.5-6.0K Unit testing. Unit #1 was non-compliant below 18.5 GHz, see Figs. 10-12, when constant bias is applied across the entire band. If bias is adjusted, injected noise can be tuned to be between 1.5-6.0K over any 2 GHz bandwidth.

Dissipated Power 15mW maximum Unit testing. Single-pixel unit was compliant, see Section 4.

Response Time 100us max rise/fall By design. Test block testing [1] showed response time limited by bias supply. RC time constants of bias circuits, both on and off MMIC, are significantly less than this time.

Stability +/-3% over 4 hours Testing of test block [1].

NOT CAL TTL Low -> Injected Noise ON By design. See Monitor and Control interface specification in section 2.

KFPA-7 NCM Compliance Matrix