Anritsu 37 C Series, Руководство по эксплуатации, Страница: 593 / 603

12
VECTOR ERROR CORRECTION
There are five built-in methods of calibration:
1) Open-Short-Load-Thru (OSLT):
This calibration
method uses short circuits, open circuits, and terminations
(fixed or sliding)
2) Offset-Short (waveguide):
This calibration method uses
short circuits and terminations.
3) LRL/LRM:
The Line-Reflect-Line (LRL) or Line-Reflect-
Match (LRM) calibration uses transmission lines and a
reflective device or termination (LRM).
4) TRM:
The Thru-Reflect-Match calibration uses short circuits
and fixed termination.
5) AutoCal ® :
This calibration method uses an automatic
calibrator module.
There are four vector error correction models available for calibration:
1) Full 12-Term
2) One Path/Two Port
3) Frequency Response
4) Reflection Only
Full 12-Term can always be used, if desired, for all models that
automatically reverse the test signal. Front-panel display indicates
the type of calibration stored in memory. A front-panel button
selects whether calibration is to be applied, and an LED lights
when error correction data is being applied.
Calibration Sequence:
Prompts the user to connect the
appropriate calibration standard to Port 1 and/or Port 2. Calibration
standards may be measured simultaneously or one at a time.
Calibration Standards:
For coaxial calibrations the user
selects SMA, 3.5 mm, GPC-7, Type N, 2.4 mm, TNC, K,
V Connector or special type from the calibration menu. Use of fixed
or sliding loads can be selected for each connector type. User
defined calibration standards allow for entry of open capacitance,
load and short inductances, load impedance, and reflection
standard offset lengths.
Reference Impedance:
It is possible to modify the reference
impedance of the measurement to other than 50
Ω
(but not 0).
AutoCal ® :
The VNA can internally control an external AutoCal
module to perform a 2-port OSLT calibration. AutoCal is a single
two port calibration module with built-in, switched, and charac-
terized OSLT standards. AutoCal provides quick, reliable, and
accurate calibrations that exceed the performance of a standard
broadband load OSLT calibration.
LRL/LRM Calibration:
The LRL calibration technique uses the
characteristic impedance of a length of transmission line as the
calibration standard. A full LRL calibration consists merely of two
transmission line measurements, a high reflection measurement,
and an isolation measurement. The LRM calibration technique is a
variation of the LRL technique that utilizes a precision termination
rather than a second length of transmission line. A third optional
standard, either Line or Match, may be measured in order to extend
the frequency range of the calibration. This extended calibration
range is achieved by mathematically concatenating either two LRL,
two LRM, or one LRL and one LRM calibration(s). Using these
techniques, full 12-Term error correction can be performed on the
37000C models.
Adapter Removal Calibration:
Built-in Adapter Removal
application software accurately characterizes and "removes" any
adapter used during calibration that will not be used for subsequent
device measurements. This technique allows for accurate
measurement of non-insertable devices.
Dispersion Compensation:
Selectable as Coaxial (non-
dispersive), Waveguide, or Microstrip (dispersive).
GAIN COMPRESSION MEASUREMENT
CAPABILITY (37300C models only)
The 37300C simplifies amplifier Gain Compression and AM/PM
measurements. Once an appropriate power and frequency
schedule is selected, a power meter calibration, at a set level, will
calibrate the linear VNA receiver channels, to accurately measure
power in dBm. The 37300C supports the Anritsu, Giga-tronics, and
Agilent power meters. To measure power, b
2
/1, a user defined
parameter, is automatically selected.
Swept Power Gain Compression:
The 37300C will display
traditional Power out vs. Power in or Phase vs. Power in, at one of
up to 10 selectable frequencies. A separate screen will easily show
Power out and Power in at 1 dB, or selected level Gain
Compression, for all entered frequencies. (Check figure below)
Swept Frequency Gain Compression:
Once Gain is
measured at the starting power, the user increments Power in,
observing Normalized Gain vs. Frequency. This aids in analyzing
the most critical compression frequencies of a broadband amplifier.
Shows Power Out and Phase performance as a function of Input
Power at a CW frequency.
HIGH SPEED TIME (DISTANCE) DOMAIN
MEASUREMENT CAPABILITY (OPTION 2)
Option 2, High Speed Time (Distance) Domain software allows the
conversion of reflection or transmission measurements from the
frequency domain to the time domain. Measured S-parameter data
is converted to the time domain by application of a Fast Fourier
Transform (FFT) using the Chirp Z-Transform technique. Prior to
conversion any one of several selectable windowing functions may
be applied. Once the data is converted to the time domain, a gating
function may be applied to select the data of interest. The
processed data may then be displayed in the time domain with
display start and stop times selected by the user or in the distance
domain with display start and stop distance selected by the user.
The data may also be converted back to the frequency domain with
a time gate to view the frequency response of the gated data.
-12.00 dBm 8.00 dBm 5.00000000 GHz CW
CH1 : b
2
/1
POWER OUT
REF = 15.000 dBm
1.000 dB/DIV CW MODE
CH3 : S21 FWD TRANS
PHASE
REF = 5.00
2.00/DIV
Phase
Power Out