ENGI 7811/9816 Winter 2017FEKO Simulation Assignment 2 Due: Friday, Feb 17, 2017

1. CIRCULAR LOOP ANTENNAS

• Read pages 41 to 53 in �Antenna Analysis and Design Using FEKO Electromagnetic Sim-ulation Software, Elsherbeni et al.�.

• Electrically small loop antennas are those whose overall length (circumference, C) is usuallyC < λ/10, where λ is the free space wavelength. On the other hand, for electrically largeloops, C ≥ λ.

• In this exercise you will examine the current distribution and the �eld patterns for bothcases noted above. In your simulation, consider the following parameters: frequency=300MHz, wire radius=0.0001λ, and

1. small circular loop, C = λ/10, and

2. large circular loop, C = λ.

(a) For both cases above, provide the following plots:

i. current (magnitude) distribution on the loop antenna,

ii. far-�eld electric-�eld pattern: 3-D electric-�eld pattern,

iii. far-�eld gain pattern: 3-D gain pattern,

iv. polar plot for the electric �eld (theta wrapped), and

v. polar plot for the electric �eld (phi) for theta=0 deg.

(b) Comment on the current distributions and far-�eld patterns for the small loop vs.the large loop.

(c) Compare the far-�eld electric �eld plots obtained for the small loop with the prin-ciple plane pattern in Slide 107 of Unit 2.

(d) How does the small circular loop �eld pattern obtained above relate to Eqs. 2.54

and 2.55 of the ~H and ~E �elds, respectively?

2.MONOPOLE ANTENNAS

• Read pages 19 to 23 in the book noted earlier.

• In this exercise you will examine a monopole antenna above an in�nite ground model.Although the �nite ground model is not considered in this exercise, you are encouraged toread/reproduce the plots in pages 22 and 23.

• Simulate a quarter-wave ultra high frequency (UHF) monopole antenna (i.e., frequency=300MHz). Consider a monopole wire radius of 0.0001λ. Provide the following:

1. Current (magnitude) distribution on the antenna,

2. 3-D far-�eld electric-�eld (magnitude) pattern,

3. 3-D far-�eld gain pattern,

4. 3-D far-�eld electric-�eld (magnitude) cuts: on the 3-D coordinate system, superimposeon a single plot the following cuts, Phi Cut (i.e., for Phi = 0◦ and 180◦) and ThetaCut (i.e., for Theta = 90◦), and

5. 3-D far-�eld gain cuts: same as (4) above.

6. Provide a short comment on the simulation results for the all cases above, and howdo they relate to the simulation results of the half-wave dipole of Problem 1 in FEKOAssignment 1?