Automatic Network Analyzer

BACKGROUND

The present invention relates generally to test equipment, and more
particularly, to an automatic network analyzer that measures continuous
wave radio frequency microwave driven transfer characteristics of
nonlinear devices and simultaneously calculates and displays corresponding
noise driven transfer characteristics and noise power ratio (NPR).

Previously, to obtain CW and noise transfer characteristics, including
noise power ratio (NPR), two separate sets of test equipment were
required, including one for CW measurements and a separate one for noise
measurements. Equipment required for noise measurements includes power
meters, spectrum analyzers and noise spectrum generating equipment.
Simulation of noise parameters may be accomplished with the use of a
separate communication software program on a separate computer.

In order to simplify the testing equipment, it would be advantageous to
have an automatic network analyzer that includes both noise and noise
power ratio measurement capability.

SUMMARY OF THE INVENTION

Tile present invention provides for a piece of test equipment comprising an
automatic network analyzer that measures continuous wave (CW) radio
frequency (RF) microwave driven transfer characteristics of nonlinear
devices and simultaneously calculates and displays corresponding noise
driven transfer characteristics and noise power ratio (NPR). The automatic
network analyzer combines the functionality of a conventional automatic
network analyzer with the ability to calculate noise parameters that
otherwise would have to be measured using separate test equipment.

The automatic network analyzer employs software or firmware that uses
closed form equations to exactly calculate noise parameters. This is done
in real-time as CW measurements are taken. Integrating the ability to make
these noise calculations and display results of the calculations
simultaneously with the CW measurements allows hardware designers the
ability to view results of adjustments to devices under test as they are
made. This is done with one piece of integrated test equipment. No other
known automatic network analyzer can view CW measurements and calculated
noise data simultaneously.

The equations are preferably provided in firmware employed in the test
equipment and use exact closed form equations to obtain predicted noise
data. To obtain noise results using currently available test equipment,
they must be either measured or simulated. Measurement normally requires
separate equipment set-up. Simulation also normally requires separate
equipment and software. Both of these testing endeavors can be expensive
and time consuming. The present automatic network analyzer provides a user
a way to see noise data in real time and allows for decreased test and
troubleshoot time during design and production of nonlinear devices, for
example.