Real Time

8. Real-time Noise Setup

Real-time Noise Setup settings are not visible if the Instrument Model Number under Configuration is PXB.

If an instrument does not have Real-time Noise capabilities, the noise effect does not work.

Real-time Noise

This cell enables or disables adding real-time, non-repeating additive white gaussian noise (AWGN) to the carrier being modulated by the waveform being played.

Carrier to Noise Ratio

Range: –100 dB to 100 dB

Default: 0.0 dB

Enter the noise power to be applied to a waveform. The carrier power is defined as the total modulated signal power before noise power is added. When you add noise, the power output from the signal generator does not change; it is the sum of carrier power and the added noise power. A positive value makes C larger than N.

Carrier Bandwidth

Range:

N5162A/N5182A: 1.0 Hz to 125 MHz

All other models: 1.0 Hz to 80 MHz 

Default: 1.0 Hz

Specifies the bandwidth over which the noise power is integrated for calculating the carrier to noise ratio (the bandwidth of the target carrier).

Noise Bandwidth Factor

Range: 1 to 2

Default: 1

Displays the flat noise bandwidth factor for the applied real-time noise.

When the Sample Clock is < 50 MHz, the Noise Bandwidth Factor adjusts the RF flat noise bandwidth to be either at least 0.8 times the sample rate for a bandwidth factor of 1, or 1.6 times the sample rate if the bandwidth factor is 2.

When the Sample Clock is > 50 MHz, noise cannot be enabled if the Noise Bandwidth Factor is 2. Any oversampling in a waveform will effectively make the noise bandwidth be that many times wider than the signal bandwidth.

The Noise Bandwidth is calculated as follows:

The noise bandwidth is at least 0.8 * [ARB Sample Clock] * [Noise Bandwidth Factor]

This parameter is not available with all instrument model numbers and may be grayed out.

Noise Bandwidth

Range: 1.0 Hz to 100.000 MHz

Default: 1.0 Hz

Set or change the noise bandwidth.

This parameter is not available with all instrument model numbers and may be grayed out.