Agilent Technologies PSA Series Manual page 371

Relative Tuned RF Level Measurement
Definition
This verification test checks the relative TRFL measurement accuracy of the PSA
spectrum analyzer that is part of the measuring receiver.
The PSA spectrum analyzer stability, linearity, attenuator switching accuracy and
preamp flatness are major contributors to the specification. However, DUT
stability, or stability of the signal source providing stimulus to the DUT are also
key contributors to meeting the relative TRFL specification.
This test differs from the linearity verification test in that this test is performed at 3
different PSA attenuator settings and with the PSA preamp on and off. Also the
effects of range switching are included.
Specification
See the PSA Specifications Guide, TRFL Specification Nomenclature, for a
graphical representation of residual noise threshold and minimum and maximum
power.
Relative Measurement Accuracy is a nominal value and not a hard specification.
Residual Noise threshold to max power:
± (0.015 dB + 0.005 dB/10 dB step) nominal
Minimum power to residual noise threshold:
± [(cumulative error + 0.0012) x (input power − Residual Noise Threshold
2
Power) ]
Residual Noise Threshold Power (dBm): Minimum power + 30 dB
Range 2 Uncertainty: ± 0.031dB
Add this value when the measuring receiver enters the range 2 state. Range 2 is
entered when the range 1 signal to noise ratio (SNR) falls between 50 and 28
dB. The SNR value is tuning band dependant. A prompt of "Range 2" on the
PSA display will indicate that the measuring receiver is in Range 2.
Range 3 Uncertainty: ± 0.031dB
Add this value in addition to the range 2 uncertainty when the measuring
receiver enters the range 3 state. Range 3 is entered when the range 2 signal to
noise ratio (SNR) falls between 50 and 28 dB. The SNR value is tuning band
dependant. A prompt of "Range 3" on the PSA display will indicate that the
measuring receiver is in Range 3.
Chapter 8
N5531S Measuring Receiver Performance Verification
Performance Verification Tests
371