Spectrum emission mask and adjacent channel power – Agilent Technologies N9010A User Manual

Page 181

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Chapter 19

181

1xEV-DO Measurement Application

Measurements

b. The relative accuracy is the ratio of the accuracy of amplitude measurements of two different transmit-

ter power levels. This specification is equivalent to the difference between two points on the scale fidel-
ity curve shown in the EXA Specifications Guide. Because the error sources of scale fidelity are almost
all monotonic with input level, the relative error between two levels is nearly (within 0.10 dB) identical
to the “error relative to -35 dBm” specified in the Guide.

Description

Specifications

Supplemental Information

Spectrum Emission Mask and
Adjacent Channel Power

Minimum power at RF Input

−20 dBm (nominal)

Dynamic Range, relative

a

Offset Freq.

Integ BW

750 kHz

30 kHz

−73.6 dB

−81.0 dB (typical)

1980 kHz

30 kHz

−78.3 dB

−83.9 dB (typical)

Sensitivity, absolute

Offset Freq.

Integ BW

750 kHz

30 kHz

−94.7 dB

−100.7 dB (typical)

1980 kHz

30 kHz

−94.7 dB

−100.7 dB (typical)

Accuracy, relative

RBW method

b

Offset Freq.

Integ BW

750 kHz

30 kHz

±0.09 dB

1980 kHz

30 kHz

±0.10 dB

a. The dynamic range specification is the ratio of the channel power to the power in the offset specified.

The dynamic range depends on the measurement settings, such as peak power or integrated power. This
specification is derived from other analyzer performance limitations such as third-order intermodula-
tion, DANL and phase noise. Dynamic range specifications are based on default measurement settings,
with detector set to average, and depend on the mixer level. Mixer level is defined to be the input power
minus the input attenuation.

b. The RBW method measures the power in the adjacent channels within the defined resolution band-

width. The noise bandwidth of the RBW filter is nominally 1.055 times the 3.01 dB bandwidth. There-
fore, the RBW method will nominally read 0.23 dB higher adjacent channel power than would a
measurement using the integration bandwidth method, because the noise bandwidth of the integration
bandwidth measurement is equal to that integration bandwidth. For 1xEVDO ACPR measurements
using the RBW method, the main channel is measured in a 3 MHz RBW, which does not respond to all
the power in the carrier. Therefore, the carrier power is compensated by the expected under-response of
the filter to a full width signal, of 0.15 dB. But the adjacent channel power is not compensated for the
noise bandwidth effect. The reason the adjacent channel is not compensated is subtle. The RBW
method of measuring ACPR is very similar to the preferred method of making measurements for com-
pliance with FCC requirements, the source of the specifications for the 1xEVDO Spur Close specifica-
tions. ACPR is a spot measurement of Spur Close, and thus is best done with the RBW method, even
though the results will disagree by 0.23 dB from the measurement made with a rectangular passband.

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