Agilent Technologies HP 8642A/B Specifiche Pagina 138

  • Scaricare
  • Aggiungi ai miei manuali
  • Stampa
  • Pagina
    / 453
  • Indice
  • SEGNALIBRI
  • Valutato. / 5. Basato su recensioni clienti
Vedere la pagina 137
Description of the Double Sided Spur Calibration
Method
An RF spectrum analyzer is required to measure the relative difference
between the fundamental signal and the spur. A spur level of —20 to
130 dBc is acceptable, however, levels within the range —26 to —60 dBc
are optimum. The calibration spur can be set at a frequency offset of 1 Hz
to 100 kHz (40 MHz with a supported RF analyzer) however 20 Hz to
50 kHz is recommended.
A modulation analyzer with phase demodulation capability can be used
in place of the RF Analyzer. In this case the sideband levels can be
determined with the following formula.
ri
. , , ,
r
, . ,
nn
. Peak Phase Deviation
biaeoand Level in dBc
2U togio
NOTE
It is important to insure that the level of the calibration
spurs are greater than the level of any other spurious
signals present in the frequency spectrum. Also, you should
evaluate both sideband calibration spurs to ensure that they
are equal in amplitude. (Any deviation in the amplitude
of the calibration spurs indicates the presence of AM in
the phase modulator.) Modulation Analyzers reject the
AM contribution to the sidebands thus removing any
inaccuracies due to AM.
Ensure that there is at least 20 dB of isolation between the drive circuit to
the R input port and the L input port of the Phase Detector by measuring
the level of the spur at both input ports. (Less than 20 dB of isolation will
cause the calibration spur to be correlated out by the phase detector.)
Calibr Process: $N w/o PLL 2-69
Vedere la pagina 137
1 2 ... 133 134 135 136 137 138 139 140 141 142 143 ... 452 453

Commenti su questo manuale

Nessun commento