Intermediate EM Waves: Image Theorem and Dipole Antennas - Prof. David Jackson, Study notes of Electrical and Electronics Engineering

Download Intermediate EM Waves: Image Theorem and Dipole Antennas - Prof. David Jackson and more Study notes Electrical and Electronics Engineering in PDF only on Docsity! Prof. David R. Jackson ECE Dept. Fall 2005 Notes 25 ECE 6340 Intermediate EM Waves Image Theorem Vertical electric dipole (VED) over an infinite ground plane PEC (E , H) dipole z E = 0 H = 0 h Image Picture (cont.) Hence, the image solution for z > 0 is the same as for the original problem. For z < 0 the image solution is not valid because the source is not the same as the original source. Vertical Magnetic Dipole Hence PEC z = 0: 0 0tE z= =at 1 2E Eφ φ= − Eφ1 Eφ2 Image picture: All Possible Cases The PMC case can be obtained from the PEC case by duality. PEC PMC Monopole Antenna (cont.) ( ) ( )I z I z− = V D (0) (0) 2 (0) (0) (0) D M D in V VZ I I = = 2D Min inZ Z= [ ] 036.5 @ 4 M inZ h λ = Ω = The image picture is a dipole antenna: I (z) + - × × s z M Eφ = − × × Corner Reflector S 0 ontE S= corner reflector: Image picture: Corner Reflector (cont.) Also, we can have this polarization: S