What is RF PCB?
In the field of electronic technology, the characteristics of radio frequency circuits are different from ordinary low frequency circuits. The main reason is that under high frequency conditions, the characteristics of the circuit are different from those under low frequency conditions. Therefore, it is necessary to use radio frequency circuit theory to understand the working principle of radio frequency PCB. Under high frequency conditions, stray capacitance and stray inductance have a great influence on the circuit. Stray inductance exists in the internal self-inductance of the wire connection and the component itself. Stray capacitance exists between the conductors of the PCB and between the components and ground. In low-frequency circuits, these spurious parameters have little effect on the performance of the circuit. As the frequency increases, the influence of the spurious parameters becomes greater. In the high frequency heads of early VHF band television receivers and the high frequency board of the front end of communication receivers, the influence of stray capacitance is so great that it is no longer necessary to add additional capacitors.
In addition, the circuit has a skin effect under radio frequency conditions. Unlike direct current, current flows in the entire conductor under direct current conditions, while current flows on the surface of the conductor under high-frequency conditions. As a result, the high frequency AC resistance is greater than the DC resistance.
Another problem in the High frequency board is the electromagnetic radiation effect. As the frequency increases, when the wavelength is comparable to the circuit size 12, the circuit becomes a radiator. At this time, various coupling effects will occur between the circuits and between the circuits and the external environment, leading to many interference problems. These issues are often insignificant under low frequency conditions.
