The definition of impedance: The total resistance generated by an alternating current flowing through a known frequency is called impedance. For a printed circuit board, it refers to the impedance of a signal layer to the nearest reference plane under the high frequency signal.

The types of impedance:

(1) Characteristic impedance. In electronic information products such as computers and wireless communications, the energy transmitted in the circuit of the PCB is a square wave signal (called pulse pulse) composed of voltage and time. The resistance encountered is called the characteristic impedance.

(2) Differential impedance. The two identical signal waveforms with opposite polarity inputs are transmitted by two differential lines, and the two differential signals are subtracted at the receiving end. The differential impedance is the impedance between the two wires.

(3) Odd mode impedance. The impedance of one line to ground in the two lines is Zoo, and the impedance values of the two lines are the same.

(4) Even mode impedance. The drive inputs two identical signal waveforms of the same polarity, and the impedance when the two wires are connected together.

(5) Common mode impedance. The impedance of the first line to ground in the two lines, the impedance values of the two lines are the same, usually larger than the odd mode impedance.

**About MAONO**

MAONO is an innovative designer and manufacturer of Lavalier, Podcasting, Wireless, Shotgun, Recording microphones and accessories for Smartphone, Camera and PC, etc.