Microwave sensors can be divided into two types: reflective and occluded:
1. Reflective type: The reflective type Microwave sensor uses the microwave signal reflected from the measured object to detect the position, thickness and other parameters of the measured object.

2. Interrupted type: Interrupted type Microwave sensor uses the microwave signal received by the receiving antenna to determine whether there is an object to be measured between the transmitting antenna and the receiving antenna, the location of the object to be measured, and the moisture content of the object to be measured.

Microwave sensor application:
1. Microwave ranging
Set up the microwave transmitter and the microwave receiver at a distance of d. The transmitter sends out a certain power microwave signal. When the microwave signal is transmitted to the receiver, there will be a part of power loss. The microwave power received by the microwave receiving antenna is sufficient. Calculate the distance h between the surface to be measured and the microwave transmitter.
2. Microwave detector
Microwave detectors use the Doppler effect of microwaves to detect moving objects: it is an active detection technology that uses the principle that the frequency shift of the reflected wave is related to the speed of the measured object, that is, the Doppler effect to detect objects. exercise. The manufacturer of Microwave sensor tells you that the relative speed can be determined based on the measured frequency shift of the beat signal. This technology has been widely used in military radar and traffic safety monitoring. The latest application field is the use of Doppler microwave probes for human motion detection.
3. Microwave measurement of water content
Under normal conditions, water molecules are randomly distributed, but because water molecules are polar molecules, under the action of an external electric field, the dipoles will form a directional arrangement. The manufacturer of the Microwave sensor tells you that the dipole of the water molecule in the microwave field changes its direction repeatedly under the action of the field, continuously absorbs energy (microwave phase shift), and continuously releases energy (microwave attenuation). Microwaves caused by the measured object with different humidity The signal phase shift and attenuation are different, and the water content of the measured object can be calculated. Microwave sensor manufacturers tell you that in practical applications, a power divider is often used to divide the power microwave signal into two channels, which are respectively injected into the measured sample and anhydrous sample through the converter, and compare the phase difference and attenuation difference between them to determine the sample content. The amount of water.
4. Microwave flaw detection
Microwave flaw detection, that is, microwave nondestructive testing, is realized by the interaction between microwave and the surface of the measured object, such as reflection, scattering, transmission, and changes in electromagnetic parameters. Microwave sensor manufacturers tell you that defects such as pores, looseness, resin cracking, delamination, and debonding will inevitably occur in composite products. The position and size of these defects in composite products and their influence on product performance under the action of temperature and external load can be assessed by microwave non-destructive testing technology.