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Calculation of characteristic impedance
2019-09-09 11:43:38
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Calculation of characteristic impedance:
Simple characteristic impedance model: Z=V/I, Z represents the impedance of each step in the signal transmission process, V represents the voltage when the signal enters the transmission line, I represents the current.I is plus or minus Q over plus or minus t, Q is the charge, and t is the time of each step.
Power (from battery) : ±Q=±C×V, C stands for capacitance, V stands for voltage.Capacitance can be derived from the unit length of the transmission line capacity CL and the signal transfer speed v.Unit value as a speed the length of the pins, then multiplied by the time needed for each step t, then get the formula: + C = CL * v * (+ / -) t. comprehensive above, we may safely draw the characteristic impedance, Z = v/I = v/(+ Q / + t) = v/(x + C v / + t) = v/(CL * v/v * (+) t + t) = 1 / (CL (v)
It can be seen that the characteristic impedance is related to the unit length capacity of transmission line and the signal transmission speed.In order to distinguish the characteristic impedance from the actual impedance Z, we add 0 after Z. The characteristic impedance of the transmission line is: Z0=1/(CL×v)


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