for the HERSCHEL mission radiometers

heartlustElectronics - Devices

Nov 2, 2013 (3 years and 9 months ago)

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Astronomical Telescopes and Instrumentation (SPIE) 8/28/02

1

Centro Astronómico de Yebes, Obs. Astronómico Nacional, IGN (Spain)

Wide band, ultra low noise

cryogenic InP IF amplifiers

for the HERSCHEL mission radiometers

Isaac López
-
Fernández
, Juan Daniel Gallego, Carmen Diez,
Alberto Barcia, Jesús Martín
-
Pintado

Centro Astronómico de Yebes

Observatorio Astronómico Nacional

Guadalajara, SPAIN

Astronomical Telescopes and Instrumentation (SPIE) 8/28/02

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Centro Astronómico de Yebes, Obs. Astronómico Nacional, IGN (Spain)

Outline


Introduction


Device characterization


Amplifier design


Amplifier fabrication


Amplifier performance


Noise and gain measurements


Reflection and stability measurements


Gain fluctuations measurements


Isolator measurements


Conclusions

Astronomical Telescopes and Instrumentation (SPIE) 8/28/02

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Centro Astronómico de Yebes, Obs. Astronómico Nacional, IGN (Spain)

Introduction: HERSCHEL requirements


HERSCHEL: Far Infrared and Submillimeter 3.5 m
Telescope orbiting in L2 with 3 cryogenic instruments


HIFI: Heterodyne Instrument for the Far Infrared with 7
dual polarization submillimeter SIS and HEB receivers


Our contribution: low noise, wide band 4
-
8 GHz cryogenic
IF preamplifiers for each mixer channel (14)


Sensitive parameters:


Noise temperature: the contribution to the receiver noise is
significant


Power dissipation: mission life limited by liquid helium mass


Gain fluctuations: impact in the chopping frequency


Other mechanical and electrical constraints

Astronomical Telescopes and Instrumentation (SPIE) 8/28/02

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Centro Astronómico de Yebes, Obs. Astronómico Nacional, IGN (Spain)

Introduction: CAY experience


More than 150 cryogenic LNAs built for different applications

(not including to HERSCHEL developments)


IRAM
: Grenoble, PdB interferometer, 30m (IF amplifiers)


ESOC
: New Northia DSN antenna (Rosetta, SMART)


Burdeos

Observatory


EMCOR

(Atmospheric sensing)


PRONAOS

(mm receiver in stratospheric balloon)


INPE
: 14m Brazil


CAY
: VLBI receivers (X and K band)


Wide experience with HEMT devices


More than 30 batches of commercial GaAs transistors tested


Several models of InP transistors measured


JPL
-
TRW (CHOP program): 14 batches, 9 models


ETH Zürich: 7 batches, 4 models


Chalmers University: 1 batch

Astronomical Telescopes and Instrumentation (SPIE) 8/28/02

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Centro Astronómico de Yebes, Obs. Astronómico Nacional, IGN (Spain)

Introduction: Initial developments


Prototypes in the 8


12 GHz band


Successful testing of InP in this band and comparison with
GaAs results


Demonstration of InP in the 4


8 GHz band

Astronomical Telescopes and Instrumentation (SPIE) 8/28/02

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Centro Astronómico de Yebes, Obs. Astronómico Nacional, IGN (Spain)

Device characterization: Transistors

Measurement procedures


InP technology selected based on previous experience in IF amplifiers


lower power dissipation, factor of 2 better noise, higher g
m


Cryogenic S parameter measurements to model devices


In
-
house test fixture with microstrip lines to allow two
-
tier TRL calibration


Device measured with bonding wires


DC and coldFET complete the small signal model


Noise model according to Pospieszalski


The noise measured in a wide band test amplifier sets the T
D

of the model

Astronomical Telescopes and Instrumentation (SPIE) 8/28/02

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Centro Astronómico de Yebes, Obs. Astronómico Nacional, IGN (Spain)

EXAMPLE OF

CRYOGENIC

S PARAMETERS

(1


40 GHz)


MODEL


Circuit model

MEAS


Raw data

MEASG


Time domain filter

Astronomical Telescopes and Instrumentation (SPIE) 8/28/02

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Centro Astronómico de Yebes, Obs. Astronómico Nacional, IGN (Spain)

Device characterization: Transistors

Results

TRW T
-
42 CRYO3



200
×
0.1 μm gate



Best performance

TRW T
-
45 CRYO4



200
×
0.1 μm gate



Used in DMs



Space qualifiable,


to be used in FMs



CHOP developed

ETH T
-
35



200
×
0.2 μm gate



Experimental


transistor



Design by request



Used in MPAs

0.22 mm

0.19 mm

Astronomical Telescopes and Instrumentation (SPIE) 8/28/02

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Centro Astronómico de Yebes, Obs. Astronómico Nacional, IGN (Spain)

Device characterization: Components


Selection of components based on previous experience at cryogenic
temperatures


SOTA thick film resistors


ATC 111 parallel plate capacitors with CA dielectric


ATC 100 multilayer porcelain capacitors


RT/Duroid 6002 substrates 20 mils thick


Simple models of concentrated elements are adequate for this frequency
range

Astronomical Telescopes and Instrumentation (SPIE) 8/28/02

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Centro Astronómico de Yebes, Obs. Astronómico Nacional, IGN (Spain)

Amplifier design


Microstrip hybrid design simulated by MMICAD software


Developed cryogenic models for transistors, connectors, critical
capacitors, resistors and bonding wires


Each InP device is independently stabilized by resistive loading and
inductive feedback


Input circuit: wideband noise matching


Tuning elements incorporated in the design

(adjustable bonding wires, microstrip islands)


Box resonances avoided with careful EM design and the use of
microwave absorbers


Multiple bias networks requirements


Contribute to the unconditional stability of the amplifier


Comply with EMC mission requirements


Provide ESD protection of sensitive InP HEMTs


Have a low drain voltage drop


Filter RF

Astronomical Telescopes and Instrumentation (SPIE) 8/28/02

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Centro Astronómico de Yebes, Obs. Astronómico Nacional, IGN (Spain)

Amplifier fabrication: several series


37

4
-
8 GHz YCF amplifiers fabricated at CAY in different series


All processes performed in our labs


Design transferred to Alcatel Espacio to build Flight Models


Series analyzed here:


YCF 2


ETH transistors (Mixer Program Amplifiers)


YCF 6


TRW transistors (Development Models)

Astronomical Telescopes and Instrumentation (SPIE) 8/28/02

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Centro Astronómico de Yebes, Obs. Astronómico Nacional, IGN (Spain)

MP amplifier YCF 2



2 stages ETH 200
µ
m



Gold plated brass



61.4
×
35
×
11.5 mm, 149 g



Duroid 6002 substrates

DM amplifier YCF 6



2 stages TRW 200
µ
m



Gold plated aluminum



58
×
32
×
15 mm, 65 g



Duroid 6002 substrates



Improved bias circuits



Additional cavity for filtering

Astronomical Telescopes and Instrumentation (SPIE) 8/28/02

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Centro Astronómico de Yebes, Obs. Astronómico Nacional, IGN (Spain)

Amplifier fabrication: reliability


Reliability is a priority over
performance for the selection of
components, substrates and
mounting techniques


Spatial design


Cryogenic operation


Past experience in cryogenic
designs obviates most of the
work in testing, modeling and
pre
-
qualifying components


An example: ‘O’ ribbon
connection in the SMA tab
contact:


Allows mobility in three axis


Excellent electrical properties
compared with traditional SMA
connections

Astronomical Telescopes and Instrumentation (SPIE) 8/28/02

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Centro Astronómico de Yebes, Obs. Astronómico Nacional, IGN (Spain)

Performance: Noise and Gain

Measurement procedures


Measurement procedure:

Cold attenuator


Two measurement systems
available at our labs:


System 350:


Older


More pessimistic


Used to keep traceability with
past measurements


All noise tests shown here
were performed with 350.


System 1020:


Newer calibration.


Gives 0.75 K better results


Estimated error (both) 1.4 K

(repetitivity < 0.2 K)

Astronomical Telescopes and Instrumentation (SPIE) 8/28/02

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Centro Astronómico de Yebes, Obs. Astronómico Nacional, IGN (Spain)

Performance: Noise and Gain

Results



Average of 3.57 K mean noise in the band for the complete DM series

Astronomical Telescopes and Instrumentation (SPIE) 8/28/02

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Centro Astronómico de Yebes, Obs. Astronómico Nacional, IGN (Spain)

Performance: Reflection and Stability


Worst case output reflection


Average MPAs:

-
14.3 dB


Average DMs:

-
13.0 dB


Model prediction of output
return losses needs refinement


Isolator at the input

(not designed for low input ref.)


Unconditionally stability for
most bias points checked with
sliding shorts

Astronomical Telescopes and Instrumentation (SPIE) 8/28/02

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Centro Astronómico de Yebes, Obs. Astronómico Nacional, IGN (Spain)

Performance: Gain fluctuations

Cryogenic measurements of DMs (TRW transistors)


Characterized by spectral density of normalized gain fluctuations:

1.
Measure S21 @ 6 GHz with HP8510 VNA (attenuator and air lines)

2.
Normalize and FFT each VNA scan (0.012
-
2.34 Hz)

3.
Average 50 spectra and subtract the system fluctuations


Fit, in the region where 1/f noise dominates, the expression

β

represents the fluctuatons @ 1 Hz and is used as


a reference for comparison between amplifiers

Astronomical Telescopes and Instrumentation (SPIE) 8/28/02

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Centro Astronómico de Yebes, Obs. Astronómico Nacional, IGN (Spain)

Performance: Gain fluctuations

Correlation with voltage fluctuations


Fluctuations of gate voltage
measured with HP35670A


Moderate correlation with gain
fluctuations for different amplifiers
measured at the same bias point


This simple DC measurements may
be useful for pre
-
selecting least
fluctuating devices from a batch

1 Hz

1 Hz

Astronomical Telescopes and Instrumentation (SPIE) 8/28/02

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Centro Astronómico de Yebes, Obs. Astronómico Nacional, IGN (Spain)

Performance: Gain fluctuations

Bias dependence


Tested the variation of gain and voltage fluctuations with drain voltage


Found a steep change in gain voltage around 0.5 V


The behaviour of gain and voltage fluctuations is similar as Vd varies


High fluctuation zones could be avoided with no penalty in noise or gain


Voltage fluctuations may help detecting these bias regions

Astronomical Telescopes and Instrumentation (SPIE) 8/28/02

20

Centro Astronómico de Yebes, Obs. Astronómico Nacional, IGN (Spain)

Performance: Isolators

Impact in overall performance


Isolators measured @ 14 K
(PAMTECH gives data @ 77 K)


Good agreement between
measurement and estimation of
isolator noise:


Mean contribution 1.1


1.4 K

Astronomical Telescopes and Instrumentation (SPIE) 8/28/02

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Centro Astronómico de Yebes, Obs. Astronómico Nacional, IGN (Spain)

Performance: Isolators

Results

Astronomical Telescopes and Instrumentation (SPIE) 8/28/02

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Centro Astronómico de Yebes, Obs. Astronómico Nacional, IGN (Spain)

Summary


34 InP HEMT 4
-
8 GHz cryogenic amplifiers fabricated for
HERSCHEL, including the Development Models with TRW transistors


Cryogenic S parameters of InP transistors measured in microstrip and
noise models developed


Cryogenic isolators used at the input allow wide
-
band mixer
-
independent design with small penalty in noise


Exceptional performance and repeatability

For the final DMs 3.5 K noise and 27
±
1.1 dB gain dissipating 4 mW


Gain fluctuations exhibit a greater dispersion


Low frequency noise of gate bias may help selecting more stable devices


High sensitivity of gain fluctuations to bias point


Gate bias noise measurements could detect bias regions of high fluctuations