Transcript Powerpoint - Cornell Astronomy

SKA TDP Receiver Antenna Interface
March 21, 2008
[email protected]
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Total system noise contributions
Choice of operating temperature
Wideband feeds under development
Quadridge feed test results
LNA status
IF/LO development
Overall plan
.19
.05
SKA Antenna and Receiver Cost for as a Function of LNA Temperature
All for Wideband Feeds with Constant A/Tsys at 1.4 GHz
SKA Antenna Concept
An antenna in the 6 to 15m diameter range requires receivers for the 0.3
GHz to an upper frequency in the 3 to 25 GHz range. The <3 GHz
frequencies will probably utilize a prime-focus uncooled feed and the higher
frequencies will probably be with a cooled feed at secondary focus.
SKA Wideband Feed Candidates
1.
2.
3.
4.
5.
ATA Log Periodic
Kildal Inverted Log Periodic
Cortes Quasi Self Complementary .
Bradley Sinous.
Lindgren Improved Quadridge
Further development is planned in 2008 followed by
integration tests
Important criteria are efficiency and system noise
temperature when integrated with LNA’s – Aeff/Tsys –
as well as low cost manufacture and maintenance.
Lindgren Quadridge Feeds
These are “quadridge/Vivaldi” antennas which operate over wide
frequency ranges which can be scaled..
They are manufactured by the ETS-Lindgren company based in Finland.
Model 3164-05, 2 to 14 GHz
Model 3164-06, 0.5 to 4 GHz
Feed Patterns Are Improved by Surrounding Feed with
Cylinder or Placing Absorber Near Feed
Measured patterns below are for H plane at 2.2, 4, 8.4, 11, 14 and 18 GHz
Feed Alone
Feed with Absorber on Outside Rim
Feed in Cylinder
Feed in Absorber-Lined Cylinder
90deg Co Polar Pattern-Aug 25, 2006 - FFS-125 Absorber in Cylinder
5
2.2GHz
5
0
2.2GHz
4GHz
0
-5
-5
-10
-10
-15
-15
-20
-20
4GHz
8.4GHz
90deg Co Polar Pattern-Aug 25, 2006 - FFS-125 Absorber in Cylinder
8.4GHz
11GHz
11GHz
14GHz
14GHz
18GHz
18GHz
-25
-25
-30
-30
-35
-35
-180
-180
-135
-135
-90
-90
-45
-45
00
4545
9090
135
135
180
180
Cryogenic Dewar Design for Lindgren Antenna
Polyethylene Window
Feed
15K Plate
LNA’s
Cryocooler
Receiver Noise Measurement on Pad at Goldstone
Raw Spectrum Analyzer Plots of LNA Outputs
with Cold Sky and 300K Absorber
Noise Spectrum at Goldstone on October 10, 2006
E4407B Resolution 1 MHz, 4-12 GHz LNA, 53 dB Preamp Gain
-50
-55
Absorber at 289K
-60
dBm
Test Setup with Feed
and LNA at 15K
-65
Sky at 5K
-70
-75
1
1.5
2
2.5
3
3.5
4
Frequency (GHz)
4.5
5
5.5
6
Prototype SKA 2-14 GHz Feed/LNA Package – Measured Noise
Lingren Vivaldi/Quadridge Cooled Feed
Lindgren Quadridge 0.5 to 4 GHz Feed Noise Tests at Goldstone
Feed Integrated with LNA Cooled at 60K by Long Life Cooler
Measured Noise of 0.5 to 4 GHz Quadridge Feed Integrated with LNA
Lower Curve is Noise of LNA + Cable
LFF Pol A. BNZ at 69K, No Filter
200
180
Noise Temperature, K
160
140
120
100
80
60
40
20
0
0.0
0.2
0.4
0.6
0.8
1.0
1.2
Frequency, GHz
1.4
1.6
1.8
2.0
Drawing of Current Quadridge to LNA Dewar Interface
Feed/LNA Interface Concept for SKA
• Dual polarization, twin-lead, high-impedance interface to feed designs
• Large uncooled feed with small LNA dewar cooled by long life 50K cooler
• Higher frequencies, > 3 GHz, in another package with cooled feed
Feed at
300K
Interface plane
to feed designs
Back
reflector
Vacuum
LNA for
Orthogonal Polarization
4-Wire Twin-Line
Zo to Match Feed
Glass-bead vacuum
feed-through
Small dewar cooled
by long-life small
cryocooler
Differential Input
LNA at 50K
Scaling of 4-Wire Feed/LNA Interface to Higher Frequencies
Dimensions must be scaled to prevent radiation from transmission lines
Frequencies above 3 GHz are best met by cooled feed.
Frequency Range
Maximum wavelength, cm, LM
Minimum wavelength, cm, LN
Line spacing = LN/16
Line diameter
Line spacing for Zo = 266, cm
Twin-lead Zo
Line length = LM/4
Maximumn frequency, GHz, Fmax
Loss , in line length, dB at Fmax
Microstrip substrate thickness, cm
Microstrip substrate thickness, inches
Microstrip substrate epsilon
Microstrip width for Zo = 133, cm
Microstrip width, inches
0.3 - 3 GHz
100
10
0.625
0.127
0.59
266.1
2.5
3
0.003
0.079
0.031
2.1
0.034
0.013
1 -10 GHz 3 -25 GHz
30
10
3
1.2
0.1875
0.075
0.041
0.015
0.19
0.07
265.8
266.6
0.75
0.3
10
25
0.005
0.009
0.025
0.01
0.010
0.004
2.1
2.1
0.011
0.0043
0.0043
0.0017
Very Low Noise Amplifier Development Status - 2008
• HEMTs - Indium-phosphide (InP) high-electron-mobility transistors
(HEMTs) have been implemented in almost all low-noise amplifiers in radio
astronomy for the past 10 years with little change in performance. This may
change with the introduction of 35nm gate length devices.
A high-speed, “do all”, semiconductor process is rapidly
being developed by several manufacturers (IBM, STM, Jazz, and others). It
combines bipolar silicon-germanium (SiGe) transistors, CMOS FET
transistors, many passive components, and several layers of
interconnection lines. The technology enables “single-chip” receivers and
feedback amplifiers with very high gain stability.
• SiGe BiCMOS -
• Feasible LNA noise temperatures in the 1 to 10 GHz range are:
– 15K to 40K at 300K
– 3K to 15K at 77K
– 1K to 5K at 15K
3.8mm
Example of a SiGe BiCMOS 77 GHz Transceiver Designed
by Hajimiri Group at Caltech
6.8mm
 Process : 0.13µm SiGe BiCMOS process.
 Transistor count: 10,000
 Complete 77GHz phased array transceiver with on-chip antennas
Noise Temperature for SiGe Transistors vs Frequency and Temperature
Based upon model measurements of 2007 IBM 0.12um wafer.
To be published in IEEE 2008 MTT Symposium
1000
300K
200K
100
77K
K
15K
10
1
0.1
1
10
Frequency, GHz
100
Measured and Modeled SiGe Cascode LNA at 15K
(3K More Noise Expected at 60K)
Vce=1.06V, Ic=6.4mA, Ib1=1uA, Ib2=1.1uA, Vb1=1.12V, Vb2=1.4V
11
33
9
Noise, K
30
Gain
27
8
24
7
21
6
18
5
15
4
12
Noise
3
9
2
6
1
3
0
0
0.0
0.5
1.0
1.5
2.0
Frequency, GHz
2.5
3.0
Gain, dB
10
IF/LO Work for TDP
There is considerable cost for the “middle” portion of the
SKA system for frequency conversion, filtering, gain
adjustment, photonic transmission, and A/D conversion.
LNA
Decade
Bandwidth
Feed
Very Low
Noise,
Cryogenic or
Ambient?
Downconverter
Single or Multiple IC
Photonic Output
Digital Signal
Processor
Spectrometer, Array
Correlelation, Beam
Forming, Pulsar
processing
Packaging Progression
1993
2003
2013
Multi-Function Chip
0.5-20GHz Quadrature Downconverter
90° HYBRID
I+ OUT
I- OUT
RF IN
LO IN
1/2
LO
I
X2
Q+ OUT
Quad. Gen.
Q- OUT
Q+
Q
RF
Image Rejection Ratio, 2.05GHz IF Frequency
Q35
30
25
IRR, dB
LO
RF
20
15
10
Lower Sideband
Upper Sideband
5
0
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
I+
I-
RF Frequency, GHz
SKA TDP Overall Hardware Plan
• During 2008 develop both 300K and 50K wideband
differential LNA’s at Caltech for the 0.3 to 11 GHz range
• Work on wideband feeds will occur independently in
2008 at Caltech and other institutions
• In 2009 integrate the best of the feed designs with LNA’s
to perform off-telescope integrated feed/LNA tests.
• In 2010 integrate feed/LNA’s with SKA reflector antenna.
Continue development of 11 to 25 GHz receivers and IF
system.
• In 2011 test the complete system
Caltech SKA TDP Statement of Work
WBS 1.2.1.3 Quad-Ridge Feeds – During the past 2 years Caltech has tested quad-ridge
wideband feeds for use on an educational 34m radio telescope (GAVRT) under contract to
the Lewis Center for Educational Research. A complete system covering 0.5 to 14 GHz
with 2 feeds will be installed on the telescope in early 2008 and this work strongly
leverages the further development of this type of system for the SKA. The design will be
investigated in 2008 and 2009 by computer-aided electromagnetic simulators and by
fabrication and test of a system with lower system noise temperature than expected with
GAVRT.
WBS 1.2.4.1 0.3-1.7 GHz Receiver – A low cost, very low noise receiver covering this
frequency range will be developed over a 4-year period utilizing either a quad-ridge feed or
other wideband feeds being developed by others. Key elements of the development are a
very low noise amplifier operating at a temperature in the 300K range with <12K noise and
very low loss connections between the LNA and feed.
WBS 1.2.4.2 1-11 GHz Receiver - A low cost, very low noise receiver covering this
frequency range will be developed over a 4-year period utilizing a selected feed. Key
elements of the development are a very low noise amplifier operating at a temperature in
the 80K range with <5K noise and very low loss connections between the LNA and feed.
The task includes design, packaging, and testing of integrated circuit low-noise amplifiers
and integration of the amplifiers with the antenna feed.
Caltech SKA TDP Statement of Work, Continued
WBS 1.2.4.3 11-25 GHz Receiver - A low noise receiver covering this high
frequency range will be developed over a 3-year starting in 2009. It is not clear at
this time whether the receiver can be included as part of the 1-11 GHz system or if the
SKA antenna will support higher frequencies/ The funds for this work element may be
needed to improve performance at the lower frequencies. Key elements of the
development are a very low noise amplifier operating at a temperature in the 60K
range with <8K noise and very low loss connections between the LNA and feed.
WBS 1.2.5.0 IF/LO Development - Experience with EVLA has shown that a large
portion of the receiver cost is in the wide bandwidth frequency conversion, local
oscillator distribution, optical fiber transducers, and A/D conversion. The goal of this
work element is to drastically reduce the cost of these functions by development of
large scale microwave integrated circuits.