KFPA Noise Calibration Module (NCM) Eric Bryerton – NRAO CDL Bethe Coupler DC 5-pin From OMT To...
Transcript of KFPA Noise Calibration Module (NCM) Eric Bryerton – NRAO CDL Bethe Coupler DC 5-pin From OMT To...
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