Field and Wave Electromagnetics 2nd Edition by David Cheng

Exercise 62

A turnstile antenna consists of two perpendicular half-wave dipoles, one (antenna A) lying along the x -axis and the other (antenna B) along the y-axis. The output of antenna B, after a 90° phase retardation, is combined with that of antenna A. A right-hand ellipti­cally polarized plane wave E i = E 0 ( a x + a y jp) exp (jkz) is incident on the antennas.
a) Determine the open-circuit voltage at the output terminals of the turnstile antenna. What is its value if p = 1
b) Repeat part (a) for a left-hand elliptically polarized incident wave E i = E 0 ( a x - a y jp) exp (jkz).
c) Repeat part (a) for a linearly polarized incident wave E i = a x E 0 exp (jkz).
(Hint: Find the complex effective length of the turnstile antenna and use Eq. 11-76.)