Initial Frequency Accuracy

This test applies to the following models with option <SYN>:

• N5290A, N5291A
• N5241B/BC, N5242B, N5244B, N5245B/BC, N5247B/BC, N5249B

• N5221B, N5222B, N5224B, N5225B, N5227B

This functional test will verify that the performance reported by the Frequency Accuracy Performance Test meets the new Initial Frequency Accuracy specification. PNA models with a high-accuracy synthesizer have a different frequency accuracy specification than models without the high-accuracy synthesizer. This test is needed to verify the new specification for those models. To facilitate testing, TME will assign option <SYN> to PNA models with this high-accuracy synthesizer. See Option <SYN> below for more information and for equipment requirements. This test will only appear if the DUT is assigned option <SYN>.

This test will use data collected from the Frequency Accuracy Performance Test. Note that the data collected must be from within the previous seven days. TME will request the operator to re-run the Frequency Accuracy Performance Test if it's been longer than the seven days.

If the results from the Frequency Accuracy Performance Test are insufficient for the Initial Frequency Accuracy test, then the operator will be asked to run the 10 MHz Frequency Reference Adjustment on the PNA. To run the adjustment, on the PNA press UTILITY > System > Service > Adjustment Routines > 10 MHz Freq Adjustment. After running the adjustment, re-run the Initial Frequency Accuracy test.

Option <SYN>

Options in angle brackets such as <SYN> are assigned by TME to facilitate testing and do not reflect product options. PNA models with a high-accuracy synthesizer have a different frequency accuracy specification than models without the high-accuracy synthesizer. (Refer to the product datasheet for information regarding the product specifications.) These models will be assigned option <SYN> by TME to support testing required for the different specification.

To determine if the UUT has this high-accuracy synthesizer and will therefore be assigned option <SYN> in TME, open the About window on the PNA. If the Synthesizer Version is 7.0 or greater, the UUT will have the high-accuracy synthesizer.

Equipment requirements for models assigned option <SYN>

• Can only use frequency counter models:

  • 53230A with Options 010 and 115
  • 53132A with Options 012 and 124

  Note the following for the 53132A:

  Option 012 (ultra-high stability timebase) is required when using an internal frequency reference.

  Option 010 (high stability timebase) is allowed when using an external frequency reference providing it has a frequency accuracy of 1.e-7 or less.

Required Test Equipment

For PNA mm-Wave systems N5290A and N5291A, click here.

 

For default front and rear cabling between the PNA and the test set, refer to Step 2: Prepare the PNA for Testing of the Getting Started Guide.

High Frequency Measurements

Low Frequency Measurements

For all other PNA models, click here.

 

High Frequency Measurements

Low Frequency Measurements

Frequency Reference Explanation

The equipment list for this test includes a FreqReference1. It is indicated as optional because it may or may not require a separate piece of test equipment. The model for this equipment type may be FreqCounter1 Internal Ref or 10 MHz External Reference. When FreqCounter1 Internal Ref is specified, the frequency counter uses its internal frequency reference for its time base; a separate piece of equipment is not required. When 10 MHz External Reference is specified, an external 10 MHz reference is required to be connected to the counter (this will often be a house standard).

The calibration date, etc, for FreqCounter1 Internal Ref should match the frequency counter. The calibration information for 10 MHz External Reference will depend on the source used for the 10 MHz.

When 10 MHz External Reference is specified, the user must provide a value for frequency accuracy. Frequency Accuracy represents the worst case accuracy of the reference (maximum deviation from exactly 10 MHz) any time during the calibration period of the reference. The value is expressed in ppm and is entered via the Additional Properties key.

As an example, if the accuracy of an external frequency reference is +/- 1.0 Hz, then the accuracy is 1.0e-7. The value in ppm would be entered as 0.10.

Frequency Accuracy Values

If a separate counter is used as the 10 MHz External Reference instead of a house standard, here are some example frequency accuracy values:

Note that values above 0.2 ppm will often give unsatisfactorily large measurement uncertainties.

Formula used to calculate the above values:

Frequency Accuracy = Time Base Error = (monthly aging rate * 12) + Temperature Stability