Standard Frequency Reference - Keysight M9290A Manual

b. In the band overlap regions, for example, 2.95 to 7.5 GHz, the analyzer may use either band for
measurements, in this example Band 0 or Band 1. The analyzer gives preference to the band with the
better overall specifications, but will choose the other band if doing so is necessary to achieve a
sweep having minimum band crossings. For example, with CF = 2.98 GHz, with a span of 40 MHz
or less, the analyzer uses Band 0, because the stop frequency is 3.0 GHz or less, allowing a span
without band crossings in the preferred band. If the span is between 40 and 60 MHz, the analyzer
uses Band 1, because the start frequency is above 2.95 GHz, allowing the sweep to be done without
a band crossing in Band 1, though the stop frequency is above 3.0 GHz, preventing a Band 0 sweep
without band crossing. With a span greater than 60 MHz, a band crossing will be required: the
analyzer sweeps up to 3.0 GHz in Band 0; then executes a band crossing and continues the sweep in
Band 1.
Specifications are given separately for each band in the band overlap regions. One of these
specifications is for the preferred band, and one for the alternate band. Continuing with the example
from the previous paragraph (2.98 GHz), the preferred band is band 0 (indicated as frequencies
under 3.0 GHz) and the alternate band is band 1 (2.95 to 7.5 GHz). The specifications for the
preferred band are warranted. The specifications for the alternate band are not warranted in the band
overlap region, but performance is nominally the same as those warranted specifications in the rest
of the band. Again, in this example, consider a signal at 2.98 GHz. If the sweep has been configured
so that the signal at 2.98 GHz is measured in Band 1, the analysis behavior is nominally as stated in
the Band 1 specification line (2.95 to 7.5 GHz) but is not warranted. If warranted performance is
necessary for this signal, the sweep should be reconfigured so that analysis occurs in Band 0.
Another way to express this situation in this example Band0/1 crossing is this: The specifications
given in the "Specifications" column which are described as "2.95 to 7.5 GHz" represent nominal
performance from 2.95 to 3.0 GHz, and warranted performance from 3.0 to 7.5 GHz.
Description

Standard Frequency Reference

Accuracy
Temperature Stability
20 to 30C
Full temperature range
Aging Rate
Achievable Initial Calibration
Accuracy
Settability
Residual FM
(Center Frequency = 1 GHz
10 Hz RBW, 10 Hz VBW)
a.
Calibration accuracy depends on how accurately the frequency standard was adjusted to 10 MHz. If the adjustment
procedure is followed, the calibration accuracy is given by the specification "Achievable Initial Calibration Accuracy".
b. For periods of one year or more.
Specifications
[(time since last adjustment  aging
rate) + temperature stability +
a
calibration accuracy ]
6
2  10
6
2  10
6
b
1  10
/year
6
1.4  10
8
2  10
Supplemental Information
(10 Hz) p-p in 20 ms (nominal)
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