Noise Sidebands > 50 kHz Offsets Performance Test

(Normal Variant Only)

This test verifies that the PSA meets its Noise Sidebands specification for offsets greater than 50 kHz from the center frequency. This test is performed in conjunction with the Noise Sidebands < 50 kHz Offsets test.

In this test, the source is connected to the RF Input and the noise level is measured at offsets of 100 kHz, 1 MHz, 6 MHz, and 10 MHz. In order to minimize the PSA DANL effects, near noise corrections are applied at each offset frequency. Near noise corrections involve measuring the noise sidebands with the RF signal On, and then measuring the DANL with the RF signal Off. Both measurements are then converted to power (in Watts), and the noise power is subtracted from the sideband power.

The resulting power is converted to dBm. The sideband power is then subtracted from the carrier power to convert the measurement to dBc. The resulting dBc measurement is normalized to 1 Hz RBW, and 2.25 dB of corrections are added. The 2.25 dB corrections account for:

  1. The Rayleigh Distribution of noise (1.05 dB)

  2. The Log Response of the PSA (1.45 dB)

  3. Equivalent Noise Bandwidth of the RBW filters (-.25 dB)

Preferred and Alternate Equipment Solutions

There are two solutions available for this test: Preferred and Alternate

Preferred solution — Wenzel source

The preferred solution uses a Wenzel Ultra Low Noise Reference Frequency Source. The Wenzel source is a fixed oscillator so the phase lock loops can be optimized for good close-in phase noise. It has a SAW filter to improve the far-out phase noise. Either Wenzel Rev C or Rev D specifications are sufficient for this test. If the Wenzel source is mapped as ETE, TME will automatically select it.

Alternate solution — source with notch filter

If the Wenzel source is not mapped, TME will select the alternate solution which uses a PSG or 8665A/B signal generator and a notch filter.

The alternate solution also allows for legacy equipment: a 1 GHz bandpass filter with the 8665A/B signal generator. TME will only select this legacy equipment if no PSG signal generators are mapped.

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Required Test Equipment

Test Equipment

Model Number

Preferred Solution

Ultra Low Noise Reference Frequency Source

Wenzel 500-13438 Rev D

6 dB Fixed Attenuator

8491A Option 006, H33

Alternate Solution

Signal Source

PSG Models1
(see equipment list)

1.0001 GHz Notch Filter

Trilithic CFN-2-1000.1

Legacy Solution

Signal Source

8665A/B

1 GHz Bandpass Filter

0955-1612

Miscellaneous Devices

50 Ω Type-N termination

909A Option 012

50 Ω 2.4 mm termination
(for E4446A/47A/48A)

85138B

BNC Cable

8120-2582 

3.5 mm Cable

8120-4921 

3.5 mm (f) to 3.5 mm (f) adapter
(for E4440A/43A/45A Option BAB)

1250-1749

3.5 mm (f) to Type-N (f) adapter
(for E4440A Option BAB)

1250-1745

Type-N (m) to 3.5 mm (f) adapter
(for E4440A/43A/45A)

1250-1744

2.4 mm (f) to 3.5 mm (f) adapter
(for E4446A/47A/48A)

11901B

Connection Setups

Preferred solution using a Wenzel source

Setup for the Displayed Average Noise Level (DANL) measurement

Alternate Solution Using PSG with a Notch Filter

Legacy solution with 8665B source and bandpass filter