Agilent Technologies N9010A - Manual (Page 217)

Chapter 23 217
CMMB Measurement Application
Measurements
Description Specifications Supplemental Information
Adjacent Channel Power
Minimum power at RF Input –36 dBm (nominal)
ACPR Accuracy
a
(7.512 MHz noise bandwidth
method = IBW
Offset Freq = 8 MHz)
±0.93 dB At ACPR –45 dBc with
optimum mixer level
b
a. The accuracy of the Adjacent Channel Power Ratio will depend on the mixer drive level and whether
the distortion products from the analyzer are coherent with those in the UUT. These specifications
apply even in the worst case condition of coherent analyzer and UUT distortion products. For ACPR
levels other than those in this specifications table, the optimum mixer drive level for accuracy is
approximately –37 dBm – (ACPR/3), where the ACPR is given in (negative) decibels.
b. To meet the specified accuracy when measuring transmitter at –45 dB ACPR, the mixer level (ML)
must be optimized for accuracy. This optimum mixer level is –19 dBm, so the input attenuation must
be set as close as possible to the average input power. For example, if the average input power is
–3 dBm, set the attenuation to 16 dB. Note that if the mixer level is set to optimize dynamic range
instead of accuracy, accuracy errors are nominally doubled.