Specifications

4
Instructions Keystrokes
Enable the noise figure measurement personality. [Preset] [Mode] ({More} if necessary) {Noise
Figure}
Enter the ENR numbers from disk. [File] {Load} {Type} {More}
{ENR Meas/Common Table} {Load Now}
You may also enter ENR values manually. Add {Meas Setup} {ENR} {Meas & Cal Table}
excess noise ratio (ENR) serial number and [Return] {Serial #}
model number. Use the numeric pad and alpha editor to enter
the serial number. If the serial number already
exists, you will be prompted to choose whether
or not you want to load the data. If not, press
{Model ID} and enter the model number using
the alpha editor and numeric key pad.
Adding ENR values versus frequency. {Index} [1] {Frequency} [10] {MHz}
{ENR Value} [13.14] {dB}
Repeat the process for index 2 and so on.
Saving the calibration data to a floppy or the [File] {Save} {Dir Select}
internal memory of the PSA. Use up/down arrows to select drive A for the
floppy, then press {Dir Select}. Press {Name}
and use the Alpha Editor to name the file
(8 characters max). When finished entering the
name, press [Return] and {Save Now}.
This exercise illustrates the different
methods of entering excess noise ratio
numbers.
The noise source used for this
demonstration is the 346C. This
noise source has a calibrated range
of 10 MHz to 26.5 GHz. There is a
pulsed 28 V source that drives the
noise source. When the voltage is on,
the output of the noise source is the
excess noise value. Once calibration
data is entered into the measurement
personality, system calibration and
DUT measurements can be made.
In most cases a common ENR table
can be used for calibration and
measurements. However, in the case
of mixers, for example, the frequency
range of the source for measurements
may be outside the range for
calibration, and therefore two
sources are required. There are
instances where the calibration
ENR table is different from the
measurement ENR table. An example
would be the analysis of the noise
figure of a frequency conversion
device (mixer). In this case there is
no longer a common table used.
Instead, the common table function
is turned off. There are two methods
of loading the ENR information into
the table. The preferred method is to
load the values from a disk supplied
with the noise source. The second
method, which is less desirable, is to
enter the excess noise ratio common
table manually.
Entering the ENR table
for a noise source