Specifications

174 Chapter 15
Sample Application Programs
Measuring the DUT with a Test Fixture
Measuring the DUT with a Test Fixture
Example 15-1 is a sample program that demonstrates how to measure a chip component
with a test fixture. You can find the source file of this program, named meas_fxt.bas, on the
sample program disk.
Start the program after mounting the test head on the fixture stand and connecting it to the
Agilent 4287A. When you are prompted with the message “Set Open-Connection,”
connect the OPEN standard to the test head's 7 mm terminal and press the
[y] key followed
by the
[Enter] key to obtain the OPEN measurement data for calculating the calibration
coefficients. Repeat the same steps to obtain the SHORT, LOAD, and LOW LOSS
CAPACITOR data for calculating calibration coefficients.
When the instrument has finished measuring the data for calculating the calibration
coefficients, the program prompts you to select the test fixture. Enter the number that
corresponds to the test fixture you want to use and then press the
[Enter] key. When you
are presented with the message “Set Open-Connection,” connect the test fixture to the test
head and set up the test fixture for OPEN measurement. Then, press the
[y] key followed
by the
[Enter] key to obtain the OPEN measurement data for calculating the compensation
coefficients. When the “Set Short-Connection” message appears, repeat the same steps to
obtain the SHORT measurement data for calculating the compensation coefficients.
NOTE For more information on using the test fixture, including how to set it up for OPEN and
SHORT measurements, refer to the test fixture's manual.
When the instrument has finished measuring the data for calculating the compensation
coefficients, the program displays the message “Set DUT, then Push [Enter] key.” Mount
the DUT on the test fixture and press the
[Enter] key. Then the instrument measures the
DUT and displays the results. After displaying the measurement results, the program
displays the message “Once more? [Y]es/[N]o.” If you want to measure the DUT again or
measure another DUT, press the
[y] key followed by the [Enter] key to continue the
measurement session. If you want to quit the measurement session, press any key except
[y] and [Enter].
The program is described in detail below:
Lines 70 to 80 Sets the GPIB address and select code.
Lines 120 to 140 Stores the active table number (No.1), the unit of the signal source
level (mA), and the number of measurement points (4 points) into the
Act_tab, Unit$, and Nop variables, respectively.
Lines 150 to 260 Stores the frequency, averaging factor, and signal source level at each
point into the Freq(*), Ave(*), and Pow(*) arrays, respectively. The
Freq(*) array contains four values of 100 MHz, 800 MHz, 1 GHz, and
3 GHz; the Ave(*) array contains “1” for all points; the Pow(*) array
contains “0.2 mA” for all points.
Lines 270 to 300 Stores the parameter settings for measurement parameters 1 through 4
into the Para$(*) array so that it contains Ls, Q, |Z|, and Rs.
Lines 290 to 320 Stores the R
dc
measurement lower limit for the OPEN standard (100
W) into the Open_l_lim variable; the R
dc
measurement upper limit for
the SHORT standard (25 W) into the Short_u_lim variable; the R
dc
measurement lower and upper limits for the LOAD standard (25 W and