There are twelve lectures in this term. Three per week beginning in 1st week. The following summarizes the content of each lecture.
Lectures 9 - 11: Review of Circuit Theory and in particular Passive Sign Convention. Solution of distributed system of discrete elements. The Telographer’s equations. Transsmission lines. Voltage and current waves down the lines and at the boundaries between transmission lines. Impedance of a length of line. ¼ wave stubs, line matching, Power delivery.
Lecture 12: The effect of the EM wave on a rarefied neutral medium of free charges (a tenuous plasma). Plasma frequency. Properties of wave transmission below and above the plasma frequency. The index of refraction of the plasma. Group and phase velocity reminder/review. Bouncing signals off the ionosphere.
Lectures 13: Metals with a finite conductivity. The propagation of EM waves inside such a material below and above the critical frequency. Properties of such metal’s index of refraction. Revisit the electromagnetic wave reflecting from the surface of the metal. Revisit power transmission down wires.
Lectures
14 & 15: The effect of the EM wave on a rarefied neutral medium of
bound charges (a tenuous gas). Index of refraction of a gas. A classical
treatment effect of closely packing the atoms together leading to dielectrics. The
electric permittivity and dielectric constant. The D-field and the Polarization (P)
field in polarisable media (dielectrics). Boundary conditions at the interfaces
between dielectrics. Revisit
Lecture 16 - 18: Reflection and refraction of EM waves at dielectric interfaces. The reasons for Snell’s Law and what more we get from Maxwell’s equations (the strength of the reflected wave). Polarization of transmitted and reflected waves and why you wear Polaroidtm Sunglasses. Brewster’s angle. Total internal reflection and the evanescent wave.
Note for Everyone: The last two lectures, if there is time, will be on material that is off syllabus, but if I run out of time then these two lectures will allow me to catch up on material I didn’t manage to cover from the above list.
Lecture 19: Guided waves. Square wave guides. TE and TM modes. If time go into dielectric wave guides and single mode optical fibres.
Lecture 20: Sources of EM waves. The retarded potentials. Solutions to Maxwell’s equations with the oscillating electric dipole as a source. Dipole radiation. Radiation resistance. Give a few things to show richness of the field and impress upon the students just how little we have been able to demonstrate for them.