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High precision metrology based microwave effective linewidth measurement technique
A precision microwave effective linewidth measurement technique for magnetic samples has been developed. The measurement utilizes a high- Q cylindrical cavity that contains the sample of interest, a highly stable and programable static magnetic field source, a computer controlled network analyzer fo...
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Published in: | Review of scientific instruments 2007-11, Vol.78 (11), p.113903-113903 |
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Main Authors: | , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | A precision microwave effective linewidth measurement technique for magnetic samples has been developed. The measurement utilizes a high-
Q
cylindrical cavity that contains the sample of interest, a highly stable and programable static magnetic field source, a computer controlled network analyzer for cavity center frequency
ω
c
and quality factor
Q
c
determinations, and the standard metrological substitution
A
B
A
method for accurate relative
ω
c
and
Q
c
measurements. Sequential long term
A
B
A
measurements show that the time and temperature drifts and random errors are the dominant sources of error, with uncertainties in
ω
c
∕
2
π
and
Q
c
in the range of
50
kHz
and 25, respectively. The
A
B
A
method is applied to eliminate these drifts and minimize the random errors. For measurements over 25
A
B
A
cycles, accuracy is improved to
0.14
kHz
for
ω
c
∕
2
π
and 3 for
Q
c
. The temperature variation over a single
A
B
A
cycle is generally on the order of
10
−
3
–
10
−
5
°
C
and there is no need for any further temperature stabilization or correction measures. The overall uncertainty in the
10
GHz
effective linewidth determinations for a
3
mm
diam,
0.5
mm
thick polycrystalline yttrium iron garnet (YIG) disk is
0.15
Oe
or less, well below the intrinsic single crystal YIG linewidth. This represents a factor of 10 improvement in measurement accuracy over previous work. |
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ISSN: | 0034-6748 1089-7623 |
DOI: | 10.1063/1.2813344 |