Electromagnetics and Microwave Enginnering

ความเร็วลอยเลื่อน (Drift velocity) คือ ความเร็วเฉลี่ยซึ่งอนุภาคเคลื่อนที่จากสนามไฟฟ้า

What is TE & TM

Unguided waves travels in the TEM (tansvers electromagnetic) form at which the electric field and the magnetic field is perpendicular to the propagation direction and both perpendicular to each other(such that foward propagation direction is detrmined by the direaction of the cross product of the electric field by the magnetic field directions)

In wave guides this TEM form is confined in the guide (guided in it) by reflections at the guide walls (either conductors or dielectrics) the resulatnt field(either elctric or magnetic)can be in any deirection so guided modes can be as follows:

TE => the resultant electric field is perpendicular to the whole mode propagation direction while magnetic field have components in that directon and in the direction that is transverse to it.

TM => same as TE but reverse the elctric field by magnetic one and the magnet. by the electric one.

HYBRID => both resulatnt elctric and magnetic fields have components in the whole mode propagation direction and in the direction transverse to it.

Note that in many wave guides the whole mode propagation direction is the wave guide axis and the TEM (before interfernce) direction is oblique to that direction.

ฺBasic Transmission Line