Fm Accuracy And Flatness - HP 8340B Manual

4-16. FM ACCURACY AND FLATNESS

Specification
FREQUENCY MODULATION
Modulation Rate: 50 kHz to 10 MHz (3 dB Bandwidth)
Peak Deviation:
Bands 0,1:
Band 2:
Band 3:
Band
41:
Deviation Accuracy (at 100 kHz rate):
Sensitivity: 1 MHz/V and 10 MHz/V
1 Band 4 only applies to the HP 8340B
FM Accuracy Description
FM Accuracy is measured by observing the modulated RF carrier on a spectrum analyzer. When the
modulation index (Peak Deviation divided by Modulation Rate) is set to exactly 2.404, the power in the
carrier will be at zero. This is called a Bessel Null.
Once the carrier has been nulled, the Peak Deviation is known precisely since the Modulation Rate is
synthesized. Since the Peak Deviation is known, the FM input voltage can be measured to calculate
the FM input sensitivity (1 or 10 MHz/V nominally). The error from nominal is expressed as a percent
and is the FM accuracy. This is measured at a 100 kHz rate.
Equipment
Spectrum Analyzer
Digital Voltmeter
Function Generator
Adapters:
APC 3.5(f) to TYPE N(in)
(1 required if DUT is HP 8340B) (2 required if DUT is HP 8341 B)
APC 3.S (f) to APC 3.S (f)
(1 required if DUT is HP 834GB)
BNC(f) to dual banana
BNC Tee (in) (f) (f)
Cables:
Semi-Rigid, (SMA male to SMA male)
BNC
HP 8340B/41B
Table 4-30. Frequency Modulation Specifications
MHz or 5
The lesser of 10
The lesser of 10 MHz or 10 x modulation rate
The lesser of 10 MHz or 15 x modulation rate
The lesser of 10 MHz or 20 x modulation rate
± 100/c
to BNC (2 required)
(in) (in)
x modulation rate
HP 8566B
HP 3456A
HP 3325A
HP P/N 12S0-1744
HP P/N S061-S311
HP P/N 1251 -2277
HP P/N 12S0.0781
HP P/N 08340-20124
HP P/N 8120-8140
4-75
Performance Tests