Practical_Antenna_Handbook_0071639586

208 P a r t I I I : H i g h - F r e q u e n c y B u i l d i n g - B l o c k A n t e n n a s
8
8
X 1
X 2
S 1
8
8
Figure 7.1 Half-wave square loop antenna.
Example 7.1 Find the inductance for each coil in a loaded half-wavelength closed-loop
antenna that must operate in a band centered on 10.125 MHz.
Solution Use Eq. (7.1).
(Note: 10.125 MHz = 10,125,000 Hz.)
8
3.6 × 10
L =
= 5.7µ
H
2 π(10,125,000)
The coils add lumped circuit inductive loading to the loop, giving it a greater effective
length in a small space. The currents flowing in the antenna can be quite high, so,