1. IRA – INAF Bologna (I) DS-6 16 September 2018 SKADS Workshop 2006
S.Montebugnoli

2. BEST-1176 sqm BEST-21410 sqm BEST-37464 sqm DS-6
DS-6 is aimed to the construction of 3 demonstrators, different in size, based on a large existing platform equipped with cylindrical concentrators (Northern Cross array located in Medicina Bologna –I-)
BEST-1176 sqm
BEST-21410 sqm
BEST-37464 sqm
16 September 2018
SKADS Workshop 2006
S.Montebugnoli

3. Achieved milestones and deliverables T1
Gantt for DS-6 T1: Design of subsystems
Deliverables:
1- Receiver: LNAs, Analog Optical link, IF stages.
2- Wideband A/D converter bit (I & Q) + DDC .
3- Reliability prediction.
16 September 2018
SKADS Workshop 2006
S.Montebugnoli

4. Achieved milestones and deliverables T2
: 2 :2
N Receivers
OL Generator
N RECEIVERS
Gantt for DS-6 T2: Development and demonstration of the BEST-1,-2,-3 large SKA platform as part of the NC (408 MHz)
16 September 2018
SKADS Workshop 2006
S.Montebugnoli .

5. Achieved milestones and deliverables T2
(Connection with DS-4 T3)
Gantt for DS-6 T2: Development and demonstration of the BEST-1,-2,-3 large SKA platform as part of the NC (408 MHz
Each BEST-x Rx is composed by 16 /2 dipoles 3o
Deterministic null steering simulation for
Best-1 (4 receivers equipped with 16 /2
dipoles each) 1=3o (RFI)
16 September 2018
SKADS Workshop 2006
S.Montebugnoli

6. Achieved milestones and deliverables T2
RFI mitigat.->MVDR
(BEST-1)
Simulation
DOA RFI
(Connection with DS-4 T3
N.sensors =4
Sensor= 16 /2 dipoles
Sensor spacing=8
Samples used for R =200
Primary beam = 2o
DOA RFI = +12o, -23o, +30o
16 September 2018
SKADS Workshop 2006
S.Montebugnoli

7. Achieved milestones and deliverables T2
RFIs mitigat.->MSC (BEST-1)
(Connection with DS-4 T3)
Preliminary test
16 September 2018
SKADS Workshop 2006

8. Achieved milestones and deliverables T2
RFIs Mitigation via Polyphase filter bank (BEST-1) (Connection with DS-4 T3)
Preliminary test
PFB
P, 
Proc.
Chan.
Contr.
Channel
Threshold
level
16 September 2018
SKADS Workshop 2006
S.Montebugnoli

9. Achieved milestones and deliverables T3
- Data simulation:
-Simulation of BEST-X data outputs
-Software validation through comparison with real BEST-X data
Milestone not reached yet (in progress):
16 September 2018
SKADS Workshop 2006
S.Montebugnoli

10. Achieved milestones and deliverables T3
Tsys computed:
The Tb distribution has been computed, according with the G.Cortes paper (“Antenna Noise Temperature Calculation”), with an ad hoc written Matlab code
BEST-1: Pn comp. GRASP model
Result (integral was resolved with an ad hoc written fortran code): Tant= 35 [K] Then the computed Tsys is: Tsys= 86.3 [K]
16 September 2018
SKADS Workshop 2006
S.Montebugnoli

11. Achieved milestones and deliverables T3
Tsys measured:
where:
½ = single polarisation
 = antenna efficiency (0.71)
Ag = BEST-1 antenna total geometrical (area ~176 m2)
k = Boltzman constant
System Equivalent Flux obtained from Cas A, Virgo, Taurus and
Cygnus-A observation
86.3 [K]
16 September 2018
SKADS Workshop 2006
S.Montebugnoli

12. Potential of FPAs for cylinders DS-6 T4
This is a T0+32 task but some preliminary considerations could be useful for other tasks (4x4 antennas subset of EMBRACE installed on the focal line of one cilyndrical concentrator)
It could be useful to test on the field the deliverables from:
DS-4 T1
DS-4 T3
DS-4 T4
DS-4 T6
16 September 2018
SKADS Workshop 2006

13. Next milestone, next deliverable (18 months)
T1 -Milestone: End of the design of BEST-2
- Start of the design of BEST-3
-Deliverables: - Analogue & digital opt. links
T2 -Milestone: - End of construction of BEST-2
- Start of construction of BEST-3
-Deliverables:- L.O. & Sync distrib. Scheme
- Wide Band high res. A/D Softw. Beamform. Algorithms(Best-2)
- Adapt. Beamf./RFI mit. Algorithms
16 September 2018
SKADS Workshop 2006
S.Montebugnoli

14. Next milestone, next deliverable (18 months)
T3 -Milestone : Test of BEST-1 & 2 data output simulation software.
Validation through
comparison with real BEST-X output data
- Deliverables: Data output simulation software for BEST-3 and other…
16 September 2018
SKADS Workshop 2006

15. Technical progress Balanced Front End: under test …. S11 -37.5 dB
IP3 dB
NF dB
16 September 2018
SKADS Workshop 2006
S.Montebugnoli

16. Link (not optimised) in the
Technical progress
IRA-INAF / Andrew analog Link
( GHz)
Gain
> 3.5 dB
Input Return loss
> 17 dB
Output Return loss
> 15 dB
Input IP3
>31 dB
Noise figure
37 dB
The Challenge to be faced is the cost reduction…..
IRA-INAF / Andrew analog Link
Link (not optimised) in the
MHz band
Gainmin
-23.7dB
Gainmax
-22.1dB
Input Return Loss
>9.5dB
Output Return loss
>24.2dB
Input IP3
>+30dBm
Noise Figure
<31.25dB
IRA-INAF analog Link
16 September 2018
SKADS Workshop 2006
S.Montebugnoli

17. Technical progress Polyphase filter bank (FX Correlator)
2x bit (Analog
Device 6645) (I/Q)
- 105 MSPS.
Xilinx Virtex 2, series 3000
16+16 bit word at
up to 4K channels
8+8 bit word at up to 8K channels
PCI Bridge
100 MHz I/Q prototype digitizer & Poliphase Filter Bank (PCI)
16 September 2018
SKADS Workshop 2006
S.Montebugnoli

18. Technical progress DS-4 DS-6 T2 DS-5 DS-3 T1-T2-T3 T1-T2 T1 RFI
BEST-1: 4 Receivers (LNA + Filter + Optical Transmitter driver) installed on a cylinder focal line, all linked via analogue optical fiber links to the processing room.
Here is the first transit of Cas A.
16 September 2018
SKADS Workshop 2006
S.Montebugnoli

19. Reliability Prediction BEST-1(DIT Florence University)
This analysis has been performed using the following tools and hypothesis :
MIL-HDBK-217-FN2 data base
series reliability model 
100% duty cycle
operating temperature: 30°C
environments:
GM (Ground Mobile) for antenna equipment
GF (Ground Fixed Uncontrolled) for cabin equipment
GB (Ground Benign Controlled) for processing room equipment
16 September 2018
SKADS Workshop 2006
S.Montebugnoli

20. BEST-1 Receiver Chain: case 1……
Reflector 8
Reflector 1
Focal line 2 3 4 5 6 7
Base band and A/D conversion GM D D C C B 4 4 4 4 4 4 B A A
Digital sampling clock and local oscillator signals
Coaxial cable
(70m)
Cabin
700m
Optical Fibre
(digital) GF
Power supply
Data
processing
8 reflectors for each cabin
4 x 8 = 32 receivers for each cabin
CLK
PPS GB
Processing room LO
408 MHz
16 September 2018
SKADS Workshop 2006

21. BEST-1Receiver Chain: case 2
Reflector 1
Reflector 8
Focal line 2 3 4 5 6 7
Base band and A/D conversion GM D D C C B 4 4 4 4 4 4 B A A
700m
Optical Fibre
(analogue)
Optical fibres
(70m)
Cabin GF
Power supply
Data
processing LO
408 MHz
8 reflectors for each cabin
4 x 8 = 32 receivers for each cabin
Processing room
CLK
PPS
16 September 2018
SKADS Workshop 2006

22. Reliability Prediction BEST-1
CASE 1- LNA ->CABLE -> A/D in the GF (cabin)
MTBF: h
1.2y
CASE 2- LNA ->Analog. Optical Link -> A/D in GB (Processing Room)
MTBF: h
4.2y
Reliability, Availability and Maintainability (RAM) analysis is an important aid in the design and management of complex systems.
16 September 2018
SKADS Workshop 2006
S.Montebugnoli

23. UPDATED DS-6 Time Table In generale 16 September 2018
SKADS Workshop 2006
S.Montebugnoli

24. Conclusion
As a general rule, the DS-6 milestones and deliverables are achieved.
The plan is to be ready with BEST-2 (maturity of the technology, costs & first astronomical observation) for the mid term review.
16 September 2018
SKADS Workshop 2006
S.Montebugnoli