Section 7.3 · Home exercises · 3 of 4
Home exercise 7.3.3: Fields and wall currents at high power
Fields and wall currents at high power
#An air-filled WR-284 guide () carries in the TE mode at .
- Find and the peak electric field . How far is it from breakdown ()?
- Find the largest values of and and where they occur.
- Find the largest surface-current density on the broad walls and on the narrow walls.
- Find the largest surface charge density.
The power fixes . Then at the centre, at the narrow walls, on a perfect conductor and .
, , :
times below breakdown.
at , and with ,
On the broad walls with and , and the largest value, along , is on the centre line. On the narrow walls the only tangential component is : , vertical.
, on the broad walls at , of opposite signs on top and bottom.
, which is of the two plane waves of TE: their is split between and by the bounce angle.
The phasor magnitudes above are not reached at the same instant: is out of phase with , so the current pattern of the figure slides along the wall at . At the wall currents are about . A flange gap or a bad joint that interrupts them sparks and radiates, which is why waveguide flanges are flat, clean and tightly bolted.