Specifications

Chapter 7 169
Measurement Result Processing
Equivalent Circuit Analysis
7. Measurement Result Processing
Example Programs for Equivalent Circuit Analysis
Below are example programs of equivalent circuit analysis. After a sweep, the equivalent
circuit model is set to E, the equivalent circuit analysis is performed, and the results are
read and displayed. In addition, frequency characteristics are simulated using the
parameters of the analysis results.
Example program using HTBasic
Example 7-5 shows an example program for the equivalent circuit analysis. This program
is saved under the filename circuit.htb on the sample programs disk. Below is an
explanation of the program’s details.
Line 60 Sets the GPIB address.
Lines 80 - 140 Substitute variables for the sweep range, number of measurement
points, trace number, sweep averaging factor, and type of equivalent
circuit model.
Line 180 Resets the E4991A.
Lines 200 - 240 Turns on Trace 1 and Trace 2. In addition, sets the measurement
parameters for each trace.
Lines 260 - 310 Sets the sweep conditions and sweep averaging function.
Lines 330 - 350 Sets the trigger source to the internal trigger and turns off the
continuous activation of the trigger system. Then, it resets the trigger
system and sets the trigger sequence to the idle state.
Line 370 Calls the sub-program for executing sweep.
Lines 390 - 400 Executes auto-scale adjustment for the trace.
Lines 420 - 430 Sets the equivalent circuit model and executes the equivalent circuit
analysis.
Lines 450 - 580 Reads and displays the values of the equivalent circuit parameter.
Lines 600 - 650 Simulates the frequency characteristics of the equivalent circuit. After
that, auto-scale adjustment is executed for both data trace and memory
trace.
Lines 690 - 710 Reads the simulation results of the frequency characteristics in the
memory trace.
Lines 730 - 780 Saves in the external computer the simulation results of the frequency
characteristics that were read.
Lines 820 - 1050 Refer to “Example Programs for Detecting Measurement End” on
page 114 for an explanation of the sub-program.
Example 7-5 Equivalent circuit analysis (HTBasic)
10 INTEGER Trc1,Trc2,Nop,Swp_count,Data_size
20 DIM Equ_model$[1],Start_f$[9],Stop_f$[9],File$[20]
30 REAL R1,C1,L1,C0,Sim_data_z(1:201),Sim_data_thd(1:201)
40 !
50 CLEAR SCREEN
60 ASSIGN @Agte4991a TO 717
70 !
80 Start_f$="50MHZ"