What is a transmission line?
Also known as telegraph equation, it is a set of differential equations explaining the relationship between voltage U and current I on a transmission line. According to the point of view of distributed parameter circuit, a short section of transmission line can be equivalent to distributed resistance R1 (ohm/meter), distributed inductance L1 (hen/meter), distributed conductance G1 (west/meter) and distributed capacitance C1 (far/meter) For a T-shaped network composed of lumped elements (for a lossless line, R1=G1=0), the actual transmission line is expressed as a cascade of equivalent networks of various segments. Assuming that the transmission line is parallel to the z-axis and the angular frequency of the time-harmonic signal is ω, the characteristic impedance, and the propagation constant, the transmission line equation can be written as its solution U(z) and I(z) are composed of two terms with factors, superscript i,r Denote the incident wave and the reflected wave respectively. Generally, the voltage and current on the transmission line are each combined by the above two traveling waves in opposite directions to form a standing wave distribution