PCB electrical length, effect on RF performance

[disisku_22]

PCB electrical length

Hi

can any one explain, what will be the effect on RF performance if the physical length is changed and what is the meaning of electrical length.
pls find the attached txlin calculator

 

[radiohead]

Re: PCB electrical length

Physical length equals the length of the transmission line expressed in millimeter. Electrical length is expressed in degrees and is the equal amount of phase shift this section will cause. This depends on the type of transmission line, substrate als hence velocity factor.

 

[kspalla]

PCB electrical length

In simple words,
In a transmission line applied with 1G Hz sinusoidal frequency all the points along the line will not have same potential.
They behave same as sinusoidal and repeat the same after some point of distance.
The minimum distance at which they posses is depend on the dielectric constant i mean it is related to lambda.

Means after every lambda distance we can see the same repeated behavior(i.e. it completes 360 deg)
90 degrees means the distance is lambda/4
From the picture
18.62mm is the distance between the maximum potential to the zero potentail.

If still in confusion please let me know.