Boundary Conditions in a Waveguide

Figure 3-24.—Simple electric fields. Figure 3-25.—Magnetic field on a single wire. the H lines take opposite directions between adjacent turns,  the  field  between  the  turns  is  canceled.  Inside and  outside  the  coil,  where  the  direction  of  each  H field is the same, the fields join and form continuous H lines around the entire coil. A similar action takes place  in  a  waveguide. Figure 3-26.—Magnetic field on a coil. BOUNDARY   CONDITIONS   IN A   WAVEGUIDE The travel of energy down a waveguide is similar, but  not  identical,  to  the  travel  of  electromagnetic  waves in  free  space.  The  difference  is  that  the  energy  in  a waveguide  is  confined  to  the  physical  limits  of  the guide. Two   conditions,   known   as   BOUNDARY CONDITIONS,  must  be  satisfied  for  energy  to  travel through  a  waveguide. The  first  boundary  condition  (illustrated  in  fig. 3-27,  view  A  can  be  stated  as  follows: For an electric field to exist at the surface of  a  conductor,  it  must  be  perpendicular to the conductor. The in  view Figure  3-27.—E  field  boundary  condition. opposite  of  this  boundary  condition,  shown B,  is  also  true.  An  electric  field  CANNOT exist  parallel  to  a  perfect  conductor. The  second  boundary  condition,  which  is  illustrated in  figure  3-28,  can  be  stated  as  follows: For a varying magnetic field to exist, it must form   closed   loops   in   parallel   with   the conductors  and  be  perpendicular  to  the electric field. 3-13


Privacy Statement - Copyright Information. - Contact Us

comments powered by Disqus

Integrated Publishing, Inc.
9438 US Hwy 19N #311 Port Richey, FL 34668

Phone For Parts Inquiries: (727) 755-3260
Google +