One of the core components of an RF capacitive level switch is its internal radio frequency (RF) circuitry, which includes one or more chips that are primarily responsible for generating, transmitting, and detecting RF signals. In RF capacitive level switches, the working principle of the RF switch chip can be summarized as follows:
Signal generation: The chip first generates a high-frequency RF signal. This signal, usually in the range of a few megahertz to tens of megahertz, is used to drive the probe.
Probe function: The probe (usually in the form of a metal rod or coaxial cable) is placed as an electrode above or in the material to be measured, and when a capacitance is formed between it and the wall of the container, this capacitance will change with the change of the dielectric constant of the material. Depending on the degree of material filling, the coupling capacitance between the probe and the material will change.
Signal transmission and detection: RF signals are transmitted to the probe through electronic circuits, and a loop is formed through the probe-material-container wall system. When the capacitance changes due to a change in the position of the material, this change affects the parameters of the RF signal, such as phase, amplitude, or frequency.
Signal processing: The receiving part of the chip detects and analyzes the returned RF signal, and determines the position or level of the material by comparing the signal difference between the no-material state and the material-with state. As soon as the capacitance changes to a preset threshold, the chip triggers the corresponding output relay action to send out a high and low level alarm or control signal.
Automatic calibration and compensation: Some advanced RF capacitive level switches use chips with integrated intelligent algorithms, which can be calibrated or automatically calibrated with one key to compensate for the effects of changes in ambient temperature and humidity to ensure measurement accuracy and stability.
Therefore, RF switch chips play a crucial role in RF capacitive level switches, which convert electrical signals into physical signals capable of detecting the presence of materials, and convert the detection results into operational electrical signal outputs.