Measurement Considerations | Using the Power Sensor |
Error States
This section details some of the error messages that may appear on the application screen. In most cases, the error condition can be easily corrected. The status LED will light yellow when an error state occurs. If not, note the error message and contact an Anritsu Service Center.
Table
Message | Description | Resolution |
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Zero invalid as temperature | The sensor’s ambient temperature has changed | Perform the zero operation again. |
changed by more than | by more than 10 ºC since the last zero |
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10 Degrees C | operation. |
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Temperature out of | Operating range of the sensor is 0 ºC to 55 ºC. | |
operating range |
| conditions. |
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Sensor zero failed | This message box appears if the zero operation | Turn off the RF input to the sensor |
| is unsuccessful. The reason could be the | or disconnect the sensor from the |
| presence of RF power at the input of the sensor. | RF source and try the zero |
|
| operation again. |
ZERO_ERROR | This message appears on the application | Turn off the RF input to the sensor |
| screen if the zero operation is unsuccessful. The | or disconnect the sensor from the |
| reason could be the presence of RF power at | RF source and try the zero |
| the input of the sensor. | operation again. |
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|
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ADC_TEMP_OVERRNGE | This message appears on the application | Remove the sensor from the USB |
| screen if the sensor is being operated in | connection and allow to cool to |
| extremely high temperatures and has | the operating range of the sensor: |
| overheated. | 0 ºC to 55 ºC |
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3-9 Measurement Considerations
Time Varying Signals
Case 1: Modulated signals with pulse or pattern repetition times ≤ 1 ms (PRF ≥ 1 KHz)
If you obtain a steady power reading of a modulated signal (no significant fluctuations of the displayed power) with no averaging, then it is likely that the pulse or pattern repetition rate is greater than 1 KHz. In this case, most of the averaging of the envelope power is performed in the front end of the sensor (before being digitized). When this is the case, the MA24106A will provide an accurate indication of the average power with no special considerations.
Case 2: Modulated signals with pulse or pattern repetition times between 1 ms and 50 ms (100 Hz < PRF < 1 KHz)
In this case, the signal is varying too slowly to be averaged in the front end of the sensor, so averaging must be performed after digitalization by increasing the averaging number in the power meter application (or calculating the average of several measurements if controlling the sensor over the bus). A large amount of averaging must be used for some pulse/pattern repetition frequencies to get a steady reading. If Low Aperture Time (LAT) mode is selected, the maximum recommended pulse repetition time is about 10 ms. If High Aperture Time (HAT) mode is selected, signals with pulse repetition periods as long as 50 ms can usually be measured.
Case 3: Modulated signals with pulse or pattern repetition times greater than 50 ms
In this case, it can be difficult to get an accurate average power reading even by averaging many readings. The sample rate of the sensor and the pulse repetition rate of the signal may be close enough that they can “beat” together resulting in low frequency modulation of the power indication. If averages are not calculated over many of these beats, or an integer number of beats, errors can result. This is not unique to the MA24106A and can be an issue with any power sensor/meter and any sampled data system.
MA24106A UG |
