fida3: a novel active array for the mid-ska
DESCRIPTION
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. Overview. - PowerPoint PPT PresentationTRANSCRIPT
O. García-Pérez (FG-IGN) 1FIDA3Wide Field Astronomy and Technologies for the SKA, Limelette, 4-6 November 2009
FIDA3: A Novel Active Array for FIDA3: A Novel Active Array for the Mid-SKAthe Mid-SKA
O. García-Pérez FG-IGN
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
O. García-Pérez (FG-IGN) 2FIDA3Wide Field Astronomy and Technologies for the SKA, Limelette, 4-6 November 2009
OverviewOverview
• Introduction
• FIDA3 prototype
• Radiating structure– Bunny-ear antennas
– Scan anomalies
– Array measurements
• Amplifiers– LNA design 1
– LNA design 2
• Conclusions
O. García-Pérez (FG-IGN) 3FIDA3Wide Field Astronomy and Technologies for the SKA, Limelette, 4-6 November 2009
IntroductionIntroduction
• 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
O. García-Pérez (FG-IGN) 4FIDA3Wide Field Astronomy and Technologies for the SKA, Limelette, 4-6 November 2009
FIDA3 prototypeFIDA3 prototypeAntennasAntennas
Box structureBox structure Feeding networkFeeding network
Low noise amplifiersLow noise amplifiers
O. García-Pérez (FG-IGN) 5FIDA3Wide Field Astronomy and Technologies for the SKA, Limelette, 4-6 November 2009
Bunny-ear antennasBunny-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.
O. García-Pérez (FG-IGN) 6FIDA3Wide Field Astronomy and Technologies for the SKA, Limelette, 4-6 November 2009
Scan anomaliesScan anomalies
Anomalies:
Resistors
• 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.
O. García-Pérez (FG-IGN) 7FIDA3Wide Field Astronomy and Technologies for the SKA, Limelette, 4-6 November 2009
Array measurementsArray measurements
1 2 3 4 5 6 7 8
9 10 11 12 13 14
15 16 17 18 19 20
25 26 27 28
21 22 23 24
31 32
29 30
Center element - scanning 32 elements - broadside
• 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.
• Reference impedance: 150Ω (diff.)
• Good measured results.
O. García-Pérez (FG-IGN) 8FIDA3Wide Field Astronomy and Technologies for the SKA, Limelette, 4-6 November 2009
DLNA design 1 (I)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 Low Noise PHEMTs ATF34-143 (Avago Tech.)
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2Frequency (GHz)
0
10
20
30
40
50
60
70
80
90
100
Noi
se T
empe
ratu
re (
K)
Noise (Measured)
Noise (Simulated) - Actual 150ohm input load
Noise (Simulated) - Ideal 150ohm input load
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2Frequency (GHz)
0
10
20
30
40
50
60
Gai
n (d
B)
Gain (Measured)
Gain (Simulated)
Noise Gain
O. García-Pérez (FG-IGN) 9FIDA3Wide Field Astronomy and Technologies for the SKA, Limelette, 4-6 November 2009
DLNA design 1 (II)DLNA design 1 (II)Mismatching effects:
Collaboration FGIGN-ASTRON
• Poor |s11| due to the high input
impedance provided by the FET in the lower part of the band.
• Mismatching effects over the active antenna impedance.
• Critical noise increase.
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2Frequency (GHz)
-20
-15
-10
-5
0
Mag
nitu
de (
dB)
|S11| (Measured)
|S11| (Simulared)
Z0=150Ω
S11
0.3 0.4 0.5 0.6 0.7 0.8 0.9 1Frequency (GHz)
050
100150200250300350400450500550600650
Noi
se t
empe
ratu
re (
K)
DLNA - 150ohm antenna
DLNA - Ideal antenna
DLNA - Actual antenna
Noise
0 1.0
1.0
-1.0
10.0
10.0
-10.0
5.0
5.0
-5.0
2.0
2.0
-2.0
3.0
3.0
-3.0
4.0
4.0
-4.0
0.2
0.2
-0.2
0.4
0.4
-0.4
0.6
0.6
-0.6
0.8
0.8
-0.8
Active antenna impedanceSwp Max
1GHz
Swp Min0.3GHz
Ideal antenna
Z0=150Ω
Z0 Z0 Z0 Z0
Active antenna impedance
0 1.0
1.0
-1.0
10.0
10.0
-10.0
5.0
5.0
-5.0
2.0
2.0
-2.0
3.0
3.0
-3.0
4.0
4.0
-4.0
0.2
0.2
-0.2
0.4
0.4
-0.4
0.6
0.6
-0.6
0.8
0.8
-0.8
Active antenna impedance_1_1Swp Max
1GHz
Swp Min0.3GHz
Actual antenna
Z0=150Ω
Active antenna impedance
Actual LNA
O. García-Pérez (FG-IGN) 10FIDA3Wide Field Astronomy and Technologies for the SKA, Limelette, 4-6 November 2009
DLNA design 2 (I)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
Low Noise PHEMTs ATF34-143 (Avago Tech.)
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2Frequency (GHz)
0
10
20
30
40
50
60
70
80
90
100
Noi
se T
empe
ratu
re (
K)
Noise (Measured)
Noise (Simulated) - Actual 150ohm input load
Noise (Simulated) - Ideal 150ohm input load
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2Frequency (GHz)
0
10
20
30
40
50
60
Gai
n (d
B)
Gain (Measured)
Gain (Simulated)
Noise Gain
O. García-Pérez (FG-IGN) 11FIDA3Wide Field Astronomy and Technologies for the SKA, Limelette, 4-6 November 2009
DLNA design 2 (II)DLNA design 2 (II)Mismatching effects:
Collaboration FGIGN-ASTRON
• |s11|<-6dB
• The mismatching effects over the active antenna impedance are not critical.
• Good noise performance in the band of interest.
0.3 0.4 0.5 0.6 0.7 0.8 0.9 1Frequency (GHz)
0
25
50
75
100
125
150
175
200
225
250
Noi
se T
empe
ratu
re (
K)
DLNA - 150ohm antenna
DLNA - Ideal antenna
DLNA - Actual antenna
Noise
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2Frequency (GHz)
-20
-15
-10
-5
0
Mag
nitu
de (
dB)
|S11| (Measured)
|S11| (Simulated) S11
0 1.0
1.0
-1.0
10.0
10.0
-10.0
5.0
5.0
-5.0
2.0
2.0
-2.0
3.0
3.0
-3.0
4.0
4.0
-4.0
0.2
0.2
-0.2
0.4
0.4
-0.4
0.6
0.6
-0.6
0.8
0.8
-0.8
Active antenna impedanceSwp Max
1GHz
Swp Min0.3GHz
Ideal antenna
Z0=150Ω
Z0 Z0 Z0 Z0
Active antenna impedance
Z0=150Ω
0 1.0
1.0
-1.0
10.0
10.0
-10.0
5.0
5.0
-5.0
2.0
2.0
-2.0
3.0
3.0
-3.0
4.0
4.0
-4.0
0.2
0.2
-0.2
0.4
0.4
-0.4
0.6
0.6
-0.6
0.8
0.8
-0.8
Active antenna impedance_1_1Swp Max
1GHz
Swp Min0.3GHz
Actual antenna
Z0=150Ω
Actual LNA
Active antenna impedance
O. García-Pérez (FG-IGN) 12FIDA3Wide Field Astronomy and Technologies for the SKA, Limelette, 4-6 November 2009
ConclusionsConclusions• 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:
– 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)
• However, some limitations appear due to its differential nature:– Scan impedance anomalies
– Noise characterization of differential LNAs
• Good measured results:– 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:
– 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.
O. García-Pérez (FG-IGN) 13FIDA3Wide Field Astronomy and Technologies for the SKA, Limelette, 4-6 November 2009
ContributionsContributions
[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
O. García-Pérez (FG-IGN) 14FIDA3Wide Field Astronomy and Technologies for the SKA, Limelette, 4-6 November 2009
THANKSTHANKS
FIDA3: A Novel Active Array for FIDA3: A Novel Active Array for the Mid-SKAthe Mid-SKA
O. García-Pérez FG-IGN
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