Basic knowledge of network analyzer - network maintenance

Time：2021-01-22                755

An overview of the network analyzer

A network analyzer is a powerful test and measurement instrument. As long as it is used and operated correctly according to the flow, it can achieve extremely high accuracy. It uses its own signal source to compare and measure other electronic equipment and electronic components. Whether the electrical characteristics and performance parameters of electronic parts, network connectors, cables, etc. meet the standards and requirements, can accurately measure the amplitude and phase information of incident waves, reflected waves, and transmitted waves, and quantitatively describe the device under test by ratio measurement. reflection and transmission properties. It is widely used and indispensable in many industries, and is especially useful for measuring the linearity characteristics of wireless radio frequency (RF) components and equipment.

This article is mainly based on the characteristics of the network analyzer itself, and introduces the steps, requirements, basic calibration methods and how to use it to perform test tasks.

When used correctly, network analyzers are some of the most accurate RF instruments, with typical accuracies of ±0.1dB and ±0.1 degrees. It makes precise, repeatable RF measurements, offering configurations and measurement capabilities as broad as their application. Choosing the right instruments, calibrations, functions, and using reliable RF measurements can optimize the results of your tests (Network Analyzer Use Case).

Second, the basic structure of commonly used network analyzers

The network analyzer is mainly composed of a signal source, a signal separation device, a receiver and a processing and display unit. We will explain in detail below.

(1) Signal source: a synthetic signal source composed of a 3-6GHz YIG oscillator, a 3.8GHz dielectric oscillator, a source module component, a clock reference and a decimal ring, which can provide a variety of signal outputs.

(2) Test device: generally composed of a directional coupler and a switch, its function is to separate the reflected signal and the incident signal, so as to perform initial signal separation and preprocessing.

(3) Signal receiver: The signal preprocessed by the test device is processed again after processing. Its function is to down-convert the signal and process the intermediate frequency digital signal for output use or display comparison. The receiver is mainly composed of sampling. / mixer, intermediate frequency processing and digital signal processing and other parts.

(4) Display: The function is intuitive, and it can be seen that the display output or signal comparison, etc., is used for high-brightness and high-speed display of characters and graphics, mainly composed of graphics processors, high-brightness LCD displays, inverters, etc. composition.

3. Precautions for instrument operation

1. When testing the product, it cannot be directly powered on for testing.

2. Before testing the power amplifier, you must check whether there is no self-excitation on the spectrum analyzer, and then use the network analyzer to measure other indicators.

3. To prevent the addition of large direct current, the network instrument can withstand the maximum direct current of 10V.

4. Prevent over-signal input.

4.1 The maximum allowable input signal of the network analyzer is 20dBm.

4.2 When the input signal is greater than 10dBm, the corresponding attenuator should be added.

5. Ensure that the instrument is grounded before use.

This article is organized and shared by Xi'an Agitek Network Analyzer Service Center. For more information on the use of network sub-maintenance, please visit Agitek Service Network (www.agitekservice.com)