1. Press the Measure function hard key, and then press the Display Type soft key.
2. From the Display Type list box, scroll to Dual and press the Enter key.
3. Press the Active Display soft key (if necessary) to select TR1 (Trace 1). Then press the Measurement Type soft key and select Insertion Loss.
4. Press the Active Display soft key to select TR2 (Trace 2). Then press the Measurement Type soft key and select Return Loss.
5. Press the Freq/Dist function hard key and set the Start Frequency and Stop Frequency. In this example, Start Frequency is set to 750 MHz and Stop Frequency is set to 900 MHz.
6. Press the Sweep function hard key and then the Data Points soft key to set the number of data points (the larger the number of data points, the longer the maximum distance, at the expense of a slower sweep speed). In this example, Data Points is set to 401.
7. Press the Shift key, then the Calibrate (2) key.
8. Press the Start Cal soft key and perform a 2-port OSL calibration.
9. When the Calibration is finished, CAL: ON (OK) should be displayed with the trace data in the instrument settings summary at the left side of the sweep window.
10. Connect VNA Port 1 and VNA Port 2 to the tuning filter.
Trace 1 (TR1: Insertion Loss) is the transmission. Trace 2 (TR2: Return Loss) is the reflection.
11. Press the Marker hard key to display the Marker menu. Then press the Marker Table soft key (if necessary) to toggle the marker table to ON.
a. Press the Marker soft key to display the Select marker list box. Select a marker (MK1 in this example) and use the touch screen or the rotary knob or the numeric keypad to set the marker on the traces.
b. Press the Marker Search soft key to set this marker at the desired location on the the traces at the lower dB setting that is specified for the filter.
c. Repeat Step a and Step b as needed to place marker MK2 on the traces at the upper dB setting that is specified for the filter.
d. Repeat Step a and Step b as needed to place marker MK3 on the traces at a point of interest (depending upon filter specifications).
12. Adjust the tuning of the filter to meet the desired specifications.
13. Press the touch screen or the Active Display soft key to toggle between the two traces.
14. Use the File menu to save measurements. refer to the file management instructions in the user guide for your instrument.
The example in this figure may not match the display on your instrument.
Filter Tuning, Log Mag – Display Type Dual – Insertion Loss and Return Loss
The example in this figure may not match the display on your instrument.
Filter Tuning, Log Mag – Display Type Overlay – Insertion Loss and Return Loss
