Filter
Top Products
58 Chapter 3
Performance Tests
Conversion Loss and Frequency Response
Performance Tests
Description
The frequency response and conversion loss are checked at four LO power levels. A known
input power is applied to the input of the mixer. The IF output power is measured on the
8566B Spectrum Analyzer. From these measurements, the conversion loss and frequency
response are calculated.
1. Connect an SMA cable from the 1st LO OUTPUT of the spectrum analyzer to the
INPUT of the amplifier. Connect a second SMA cable to the OUTPUT of the amplifier.
2. For 11970K: Zero and calibrate the power meter. For 11970A, 11970Q, 11970U, 11970V
or 11970W: Connect the 478A Power Sensor to the power meter sensor cables, then zero
the power meter.
3. Set the 8566A/B Spectrum Analyzer controls as follows:
SHIFT, ↑, KSU
FREQUENCY SPAN, 0, Hz
SHIFT
, SWEEP, CONT, KSt
CENTER
, 2, 4, [.] 5, GHz
CAUTION When you are using a 11975A Amplifier with a 11970 Series Mixer, you
MUST set the amplifier rear-panel ALC switch to ON before you connect the
amplifier into the test setup. If the ALC switch is left in the OFF position, the
amplifier output power is high enough to destroy the mixer diodes.
4. On the 11975A Amplifier, set the rear panel ALC switch to ON, then connect the power
sensor to the free end of the cable installed on the OUTPUT connector of the amplifier.
Set the power meter Cal Factor to the appropriate value for a frequency of 4 GHz.
5. Adjust the amplifier OUTPUT POWER LEVEL for a reading of 14.0 ± 0.1 dBm on the
power meter. Record the LO power in Table 3-7.
6. Set the power meter Cal Factor to 100 percent.
7. Connect the equipment, as shown in Figure 3-1.
CAUTION Make sure the 8349A Amplifier, used in the signal generator system for
11970A, Q and U tests, is set for external leveling before you turn it on.
Failure to do so may allow the amplifier output to rise about 20 dBm (high
enough to damage the frequency tripler).
8. Set the signal generator for a CW output signal at the frequencies listed below:
11970K: 18.0 GHz
11970A: 26.5 GHz
11970Q: 33.0 GHz
11970U: 40.0 GHz