## How do you measure the noise of a spectrum analyzer?

Set the spectrum analyzer’s video bandwidth (VBW) to be 1% or less the value for the resolution bandwidth. Press the Marker Function (MKR FCTN) key, then the Noise Marker On soft key. Position the marker to the frequency where you wish to measure noise figure.

## What is ENR noise figure?

ENR refers to Excess Noise Ratio which is 10 log {(Th-290)/290} essentially a normalized measure of how much the noise source is above thermal in its power. At high ENRs > 15 dB the density of power can be approximated by adding the ENR to -174 dBm/Hz.

**How can you reduce the real time noise floor in a spectrum analyzer measurement?**

The noise floor is determined by the resolution bandwidth and the input attenuator setting. Assuming the attenuator is set to zero, the noise power is given by KTB + noise figure of the spectrum analyzer. Assuming the noise figure is fixed, then KTB can only be changed by changing B, the bandwidth of the measurement.

**How can I improve my noise figure?**

Noise figure analyzer uncertainty can be significantly improved via the use of a pre-amplifier before the measurement system. The pre-amplifier should have substantial gain combined with a low noise figure. The fundamental goal of the pre-amplifier is a reduction in the overall “system” noise figure.

### How is noise figure calculated?

We read the output noise density to be -90dBm/Hz. To get a stable and accurate reading of the noise density, the optimum ratio of RBW (resolution bandwidth) and VBW (video bandwidth) is RBW/VBW = 0.3. Thus we can calculate the NF to be: -90dBm/Hz + 174dBm/Hz – 80dB = 4.0dB.

### How do you measure noise figure?

Noise Figure Measurement Methods It involves applying a noise source to the input of the DUT and making noise power measurements at the output of the DUT. By doing this, a ratio of noise power measurements, the Y-Factor, is determined and noise figure is derived from that.

**How do you reduce noise floor in RF?**

A common way to lower the noise floor in electronics systems is to cool the system to reduce thermal noise, when this is the major noise source. In special circumstances, the noise floor can also be artificially lowered with digital signal processing techniques.

**What is the noise floor on a spectrum analyzer?**

Noise floor is an important parameter in spectrum analyzers and vector network analyzers. It determines the lowest possible signal level that these systems can measure. For example, to measure a signal that is -140 dBm, the system must have a noise floor of less than -140 dBm.

#### What is a good noise figure?

A typical professional or ham HF radio receiver may have a noise figure of 15 dB of more and function quite satisfactorily. A better level of performance is not necessary because of the high level of atmospheric noise.

#### What is the ideal noise figure in dB?

A high value of noise figure indicates system degradation and poor performance. A typical RF system with cellular and ISM applications in the operating range of 400 MHz to 1500 MHz has a noise figure in the range of 0.9 dB in the low gain mode and 2.3 dB in the high gain mode.

**What is the ideal value of noise figure?**

For an ideal amplifier, when a signal passes through the system, then no noise is added to the signal, and input SNR is equal to the output SNR and hence NF for the ideal amplifier is 1 or 0 dB.

**What is the difference between noise figure and noise factor?**

The noise factor is thus the ratio of actual output noise to that which would remain if the device itself did not introduce noise, or the ratio of input SNR to output SNR. The noise figure is simply the noise factor expressed in decibels (dB).