Network analyzer (electrical)
A network analyzer (electrical) is an electronic instrument used to characterize the electrical behavior of electrical networks, especially their response to radio frequencies (RF) and microwaves. It measures network parameters, which are electrical properties of the network such as scattering parameters (S-parameters), impedance, admittance, and gain/loss over a range of frequencies. These parameters provide a comprehensive description of how the network modifies signals passing through it.
The core function of a network analyzer is to generate a known test signal and then measure how that signal is affected after passing through the device or network under test (DUT). By analyzing the changes in magnitude and phase of the signal at various frequencies, the network analyzer determines the network's characteristics.
Key components of a network analyzer typically include a signal source, a test set (containing signal separation devices such as directional couplers and bridges), a receiver for measuring the signal, and a display and control unit for operating the instrument and presenting the results. Advanced network analyzers incorporate sophisticated calibration techniques to minimize systematic errors and ensure accurate measurements.
Network analyzers are widely used in the design, testing, and maintenance of RF and microwave circuits and systems. Applications include:
- Characterizing filters, amplifiers, antennas, cables, and other RF components.
- Verifying the performance of communication systems.
- Matching impedance in transmission lines.
- Analyzing signal integrity in high-speed digital circuits.
- Materials research and dielectric property measurements.
There are two primary types of network analyzers: scalar network analyzers (SNAs) and vector network analyzers (VNAs). SNAs measure only the magnitude of the signal, providing information about gain or loss. VNAs, on the other hand, measure both the magnitude and phase of the signal, enabling a more complete characterization of the network's behavior, including impedance matching and reflection characteristics. VNAs are considerably more versatile and are the industry standard for comprehensive RF and microwave network analysis.