Transcript FIDA3 - Square Kilometre Array

FIDA3: A Novel Active Array for
the Mid-SKA
O. García-Pérez
FG-IGN
[email protected]
J.A. López-Fernández, D. Segovia-Vargas, L.E. García-Muñoz,
V. González-Posadas, J.L. Vázquez-Roy, J.M. Serna-Puente, E. Lera-Acedo,
T. Finn, R. Bachiller and P. Colomer
Wide Field Astronomy and Technologies for the SKA,
Limelette, 4-6 November 2009
FIDA3
O. García-Pérez (FG-IGN) 1
Overview
•
Introduction
•
FIDA3 prototype
•
Radiating structure
– Bunny-ear antennas
– Scan anomalies
– Array measurements
•
Amplifiers
– LNA design 1
– LNA design 2
•
Conclusions
Wide Field Astronomy and Technologies for the SKA,
Limelette, 4-6 November 2009
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O. García-Pérez (FG-IGN) 2
Introduction
•
FIDA3 (FG-IGN Differential Active Antenna Array) is an active array prototype
developed by the FG-IGN for the task DS4-T4 of the SKADS project.
•
It should meet the next requirements:
– Bandwidth: 300MHz-1000MHz
– Low cost
– Dual polarization
– Scanning capabilities up to +/-45º
– Noise temperature as low as possible
•
The proposed solution provides the next advantages:
– Dielectric-free antennas: avoid the losses and cost of the substrate
– Differential feeding: avoids the losses and bandwidth limitations of passive baluns
Wide Field Astronomy and Technologies for the SKA,
Limelette, 4-6 November 2009
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O. García-Pérez (FG-IGN) 3
FIDA3 prototype
Antennas
Low noise amplifiers
Box structure
Wide Field Astronomy and Technologies for the SKA,
Limelette, 4-6 November 2009
FIDA3
Feeding network
O. García-Pérez (FG-IGN) 4
Bunny-ear antennas
•
Bunny-ear antennas:
– Similar band to classical Vivaldi antennas.
– Better performance at lower frequencies.
– Easy to manufacture.
– 150 ohm reference impedance (in diff. mode).
– Simulation of an infinite array with HFSS.
– Differential feeding: avoids the losses and the bandwidth limitations of a passive
balun.
– No substrate: reduces cost and potential losses.
Wide Field Astronomy and Technologies for the SKA,
Limelette, 4-6 November 2009
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O. García-Pérez (FG-IGN) 5
Scan anomalies
•
Scan anomalies appear due to the propagation of
common-mode currents.
•
The even-mode currents can be dissipated by connecting
two resistors (3kΩ) between the feeding lines and GND,
and therefore the anomalies disappear.
•
Optimized design: VSWR<2.5:1, scanning up to 45º.
•
Extra noise contribution lower than 10K.
•
IEEE TAP accepted for publication.
Anomalies:
Resistors
Wide Field Astronomy and Technologies for the SKA,
Limelette, 4-6 November 2009
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O. García-Pérez (FG-IGN) 6
Array measurements
•
Array tile: 32 elements per polarization.
•
Passive baluns to convert from
differential to single-ended mode.
•
Active impedance calculated from the
measured S-param of the array.
9
•
•
Reference impedance: 150Ω (diff.)
Good measured results.
Center element - scanning
Wide Field Astronomy and Technologies for the SKA,
Limelette, 4-6 November 2009
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30
21
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24
10
11
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13
14
2
3
4
5
6
7
15
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18
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25
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27
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31
32
8
32 elements - broadside
FIDA3
O. García-Pérez (FG-IGN) 7
DLNA design 1 (I)
Differential LNA #1:
•
Avago PHEMTs: ATF34-143
•
Hot/cold test at ASTRON.
•
Good results for 150Ω source
impedance:
–
T<52K
–
G>26dB
Noise
Wide Field Astronomy and Technologies for the SKA,
Limelette, 4-6 November 2009
Low Noise
PHEMTs
ATF34-143
(Avago Tech.)
Gain
FIDA3
O. García-Pérez (FG-IGN) 8
DLNA design 1 (II)
1.0
0.8
6
Swp Max
1GHz
2.
4
3.
Actual LNA
0
0
4.
5.0
0.2
10.0
5.0
4.0
3.0
2.0
Z0=150Ω
2
0
.0
.0
Critical noise increase.
-2
.0
.4
-3
-0
-4
-0.
-5.
Mismatching effects over the
active antenna impedance.
1.0
0
Z0=150Ω
0.8
0.6
0.4
0.2
10.0
-10.0
-0.8
Z0
-1.0
.6
Ideal antenna
Z0
-0
•
0.
•
Poor |s11| due to the high input
impedance provided by the
FET in the lower part of the
band.
0
0.
Collaboration FGIGN-ASTRON
•
Active antenna impedance
Active
impedance
Activeantenna
antenna impedance
Mismatching effects:
Z0
Z0=150Ω
Z
Swp Min 0
0.3GHz
Noise
S11
Wide Field Astronomy and Technologies for the SKA,
Limelette, 4-6 November 2009
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O. García-Pérez (FG-IGN) 9
DLNA design 2 (I)
Differential LNA #2:
Collaboration FGIGN-ASTRON
•
Avago PHEMTs: ATF34-143
•
Inductive degeneration.
•
Good results for 150Ω source
impedance:
–
T<40K
–
G>26dB
Noise
Wide Field Astronomy and Technologies for the SKA,
Limelette, 4-6 November 2009
Low Noise
PHEMTs
ATF34-143
(Avago Tech.)
Gain
FIDA3
O. García-Pérez (FG-IGN) 10
DLNA design 2 (II)
1.0
0.8
6
Swp Max
1GHz
2.
0
0.
Collaboration FGIGN-ASTRON
4
|s11|<-6dB
•
The mismatching effects over
the active antenna impedance
are not critical.
0.
•
3.
Actual LNA
0
0
4.
10.0
5.0
4.0
3.0
2.0
1.0
0
Z0=150Ω
0.8
0.6
0.4
0.2
10.0
Z0=150Ω
-10.0
2
0
.0
.0
-2
.0
.4
-3
-0
-4
-0.
-5.
Good noise performance in the
band of interest.
5.0
0.2
•
Active antenna impedance
Active
impedance
Activeantenna
antenna impedance
Mismatching effects:
-1.0
Z0
-0.8
-0
.6
Ideal antenna
Z0
Z0
Z0=150Ω
Z
Swp Min 0
0.3GHz
Noise
S11
Wide Field Astronomy and Technologies for the SKA,
Limelette, 4-6 November 2009
FIDA3
O. García-Pérez (FG-IGN) 11
Conclusions
•
•
The design of an active array receiver for the 300MHz-1000MHz frequency range of the
Square Kilometre Array (SKA) radio-telescope has been presented.
The proposed solution provides the next advantages:
–
–
–
•
However, some limitations appear due to its differential nature:
–
–
•
Scanning capabilities up to 45º with acceptable active reflection coefficient.
LNA noise temperature lower than 40K for 150Ω source impedance.
Finally, the matching condition effects between the antenna and the LNAs are
analyzed:
–
–
•
Scan impedance anomalies
Noise characterization of differential LNAs
Good measured results:
–
–
•
Dielectric-free structure: reduces the cost and the losses
Differential feeding: avoids the use of a passive balun
Reduced number of LNAs/m2 (~ 70.86 lna/m2)
The LNA input reflection coefficient should be well matched to the antenna impedance.
If not, the active antenna impedance will be mismatched, and the noise of the receiver may
increase.
Future lines: System integration and hot/cold tests with the active array tile.
Wide Field Astronomy and Technologies for the SKA,
Limelette, 4-6 November 2009
FIDA3
O. García-Pérez (FG-IGN) 12
Contributions
[1] E. Lera-Acedo, L.E. Garcia-Muñoz, V. Gonzalez-Posadas, J.L. Vazquez-Roy,
R. Maaskant, D. Segovia-Vargas, “Study and design of a differentially fed
tapered slot antenna array”, IEEE Trans. Antenn. Propag., 2009. accepted
[2] O. Garcia-Perez, D. Segovia-Vargas, L.E. Garcia-Muñoz, J.L. Jimenez-Martin,
V. Gonzalez-Posadas , “Design, characterization and measurement of
broadband differential low noise amplifiers for active differential arrays”, IEEE
Trans. Microw. Theory Tech., 2009. submitted
Wide Field Astronomy and Technologies for the SKA,
Limelette, 4-6 November 2009
FIDA3
O. García-Pérez (FG-IGN) 13
FIDA3: A Novel Active Array for
the Mid-SKA
THANKS
O. García-Pérez
FG-IGN
[email protected]
J.A. López-Fernández, D. Segovia-Vargas, L.E. García-Muñoz,
V. González-Posadas, J.L. Vázquez-Roy, J.M. Serna-Puente, E. Lera-Acedo
T. Finn, R. Bachiller, P. Colomer
Wide Field Astronomy and Technologies for the SKA,
Limelette, 4-6 November 2009
FIDA3
O. García-Pérez (FG-IGN) 14