HP 8340B Manual page 42

4-8. SPURIOUS SIGNALS TEST, 22 to 26.5 GHz (Applies only to HP 8340B)
(Cont'd)
UNDER TEST
Description
The HP 8340B Under Test RF output signal is fed through a 20 dB pad and a high pass filter and is
then down converted using a mixer and an HP 8340A/B as a Local Oscillator. the mixer output is fed to
a low frequency spectrum analyzer.
The DUT is set to a CW frequency. All possible harmonics of the RF signal and harmonics of the YO
frequency that could fall within the 22 GHz to 26.5 GHz range are determined.
The LO is set to a CW frequency 50 MHz below each harmonic. The specification is in dB below the
carrier. To establish the carrier level at the IF, the DUT is temporarily set to the frequency of the
harmonic and a reference level is established on the Spectrum Analyzer. The DUT is returned to the
original CW frequency. The amplitude of the harmonic displayed on the Spectrum Analyzer is used to
determine that the harmonic is at or below the specified level.
4-42 Performance Tests
lIP 8340B
Figure 4-8. Spurious Signals Test Setup (22 to 26.5 GHz)
LOCAL OSCILLATOR
ADAPTERS
(HIGH PASS FILTER)
HP K281C
(STD)
RF
OUTPUT
HP 8340B/41B