The principal investigator of UQ Photonics group decides to characterise newly arrived concrete
项目类别：电气电力工程
THE UNIVERSITY OF QUEENSLAND SCHOOL OF ELECTRICAL ENGINEERING and COMPUTER SCIENCE
ELEC3100 FUNDAMENTALS OF ELECTROMAGNETICS
Week 9 - Problems to Solve
Problem 1 The principal investigator of UQ Photonics group decides to characterise newly arrived concrete blocks non-destructively by using a monochromatic low-frequency electromagnetic probe with frequency at = 1 GHz. To get a rough idea what’s going on, researchers decide to treat the low-frequency wave as a uniform plane time-harmonic field with rms electric field intensity !" = 1 V/m. The lab technician manages to run the transmission-type experiments in air. Now, this wave passes through the air and eventually impinges on the flat surface of a bulky concrete block perpendicularly. The concrete block material parameters are given as # = 6, = 2.5 ⋅ 10$% S/m and # = 1. (a) Now, you need to determine if the concrete block is a good dielectric, good conductor, or quasi conductor, and find electric and magnetic fields in both media, (b) Find the standing wave ratio in air (c) Find the time average Poynting vector in the second medium (d) Compute the percentages of the time average incident power that are reflected from the interface and transmitted into the material block, respectively.
Problem 2 A TEM wave propagating in air for y>0 is incident obliquely on a perfect electric conductor screen occupying the plane y=0.The complex rms electric field intensity vector of the wave is given by = '((*+√%-)3 (V/m). You need to: (a) Make a sketch for the situation and, (b) Calculate the electric and magnetic field vectors of the resultant wave at an arbitrary position in air.
Problem 3 A 200-MHz left-hand circularly polarised plane wave with an electric field modulus of 5 V/m is normally incident in air upon a dielectric medium with ! = 4 and occupying the region defined by ≥ 0.
