Agilent Technologies E4406A manual Using the Marker, Changing the Display, Troubleshooting Hints

Making Measurements

Making the Channel Power Measurement

Changing the Display

The AMPLITUDE Y Scale key accesses the menu to set the desired vertical scale and associated settings:

•Scale/Div - Allows you to enter a numeric value to change the vertical display sensitivity. The range is 0.10 to 20.00 dB with 0.01 dB resolution. The default setting is 10.00 dB. However, since the Scale Coupling is defaulted to On, this value is automatically determined by the measurement result.

•Ref Value - Allows you to set the absolute power reference value ranging from −250.00 to 250.00 dBm with 0.01 dB resolution. The default setting is 10.00 dBm. However, since the Scale Coupling is defaulted to On, this value is automatically determined by the measurement result.

•Ref Position - Allows you to set the display reference position to either Top, Ctr (center), or Bot (bottom). The default setting is Top.

•Scale Coupling - Allows you to toggle the scale coupling function between On and Off. The default setting is On. Upon pressing the Restart front-panel key or Restart softkey under the Meas Control menu, this function automatically determines the scale per division and reference values based on the measurement results.

Using the Marker

The Marker key is not available for this measurement function.

Troubleshooting Hints

If an external attenuator is used, be sure to use the Ext RF Atten key to include the attenuation value in the displayed measurement result.

The channel power measurement, along with the adjacent channel power ratio measurement and spectrum measurements, can reveal the effects of degraded or defective parts in the transmitter section of the UUT. The following are areas of concern which can contribute to performance degradation:

•DC power supply control of the transmitter power amplifier, RF power control of the pre-power amplifier stage, and/or I/Q control of the baseband stage.

•Gain and output power levels of the power amplifier, caused by degraded gain control and/or increased distortion.

•Amplifier linearity.

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