A network analyzer is a complex device used in testing equipment or components of equipment that communicate electronically through a network. It may be attached directly to equipment or to a network hub. A network analyzer can provide detailed, real-time statistics about network activity and packets of data sent through the network. It is often used to monitor network traffic, identify network problems, or to aid in the development of new hardware or software that makes use of a network. Other names for a network analyzer include packet sniffer, traffic analyzer and protocol analyzer.
Conversion loss is a measurement of the efficiency of electrical signals travelling through a network. As data is converted into electrical signals, it loses a portion of its original energy. Conversion loss is measured by analyzing the strength of the input signal against the strength of the output signal.
Directivity is the measure of a network signal as it travels in different directions through a network. Some signals may travel faster, stronger or more efficiently in one direction than another.
Dynamic range is the measurement of the highest and lowest signal voltage or power being transmitted through a network. It can be expressed as the difference between the two or as a ratio.
Frequency resolution is a measure of the number of peaks a wave has in a given timeframe. The higher the frequency, the more peaks the wave will have.
Group delay measures phase distortion in a network signal caused by an electronic device through which the signal passes. It is represented as the actual time it takes for a signal to transmit through the device.
After a network analyzer acquires a network signal, the signal is converted into an intermediate frequency (IF) wave for analysis. The bandwidth of this wave is adjustable, and reducing it may reduce the noise in the transmission.
Magnitude, Log or Linear
Magnitude is one of the S-parameters measured by a network analyzer. It is the strength of the network signal. Magnitude is usually expressed in a logarithmic format using decibels, but it can also be expressed in a linear format as a ratio or in watts. Log magnitude, or log mag often measures return loss, while linear mag is used for reflection and transmission coefficients.
Markers are highlighted points on a network analyzer trace that are used to easily identify network signal values within given parameters.
Network Analyzer Ports
Network analyzer ports are the sockets through which signals are collected by a network analyzer from a network and sent back through the network.
The noise floor is the collective measure of all noise from all sources within a network.
Output Power Range
Output power range represents the maximum and minimum strengths of signals passing through a network. The most efficient transmissions are near the median output power range.
Return loss is also often referred to as reflection loss. It is the amount of signal strength reduced from the original signal due to reflections of the signal through the network line. The term return loss is used because reflected signals often return to the signal source.
RF/Microwave Network Analyzer
A radio frequency (RF) or microwave network analyzer is used to measure signal properties passing through a wireless network.
Short for scattering parameters, S-parameters are used to describe the wavelengths of microwaves or smaller types of waves moving through circuits or a network. S-parameters measure how much energy breaks off the original signal and exits via radiation or through ports other than the receiving port.
Scalar Network Analyzer
A scalar network analyzer (SNA) is one of two basic types of network analyzer. It can measure the properties of a network signal only in relation to the amplitude of the signal.
A smith chart is a circular, plotted graph of the reflection and impedance of a network signal. Real impedance is represented on a classic Smith chart, but a Smith chart may also represent imaginary or possible impedance.
Source match is the loss of a portion of a network signal when a signal reflection reenters the port where the signal originated.
Sweep, Types of
Sweep refers to how network signals are acquired by a network analyzer. Several types of sweeps may be used for various purposes. Sweep types are divided into three primary categories: single sweeps, up-down sweeps and split range sweeps.
SWR is an abbreviation for standing wave ratio, which is a comparison of the maximum strength of a communications signal a device may produce to the actual strength of the signal leaving the device. SWR is usually measured in volts.
The trace is a line graph of network activity that appears on the display of a network analyzer. Network activity may make the trace appear jittery by marking points created by noise. Many network analyzers have a smoothing feature that creates a trace that is easier to read.
A network analyzer must periodically be checked that it is reading accurately through one or more types of standardized calibration. One type of calibration is thru, reflect, line (TRL) calibration, which is considered one of the more accurate types. TRL calibration ensures accurate reading of signals passing through the network, signal reflection and line impedance. Another type of calibration related to TRL calibration is line, reflect, match (LRM) calibration. This type replaces thru calibration with match calibration, which is actually another form of line calibration.
Vector Network Analyzer
A vector network analyzer (VNA) is one of the two basic types of network analyzer. A VNA can measure the properties of a network signal in relation to the amplitude and the phase of the signal.