Design of Antennas for Handheld DVB-H ... - Lunds tekniska högskola

Figure 5.6. Radiation pattern for Reference antenna, frequency=560 MHz,
Theta=0°-350°, Phi=90°, A=Phi polarization, B= Theta polarization.
To determine the power gain for our antennas we must measure the radiated
signal in the whole sphere. The maximum value of all these values is equivalent to
2.15 dBi power gain for an ideal dipole, because our reference antennas are not
ideal we estimated the maximum power gain to 1.6 dBi. Then the maximum
absorbed signal for our antennas can be compared with this value for respective
frequency (see equation 5.1).
G=A-B+1.6 (5.1)
G=Antenna power gain in dBi.
A=Received signal strength in our prototype.
B=Received signal strength in the reference antenna.
To find out the efficiency for our antennas we must calculate TRP, total radiated
power for both the reference antenna and our prototype.
2π
π
⎧
⎫
Prad = B0
∫ ⎨∫
f ( θ ) ⋅ sin θ ⋅ dθ
⎬dφ
0 ⎩ 0
⎭
Numerical equation:
(5.2)
P
rad
⎛ π ⎞⎛
2π
⎞
= B0⎜
⎟⎜
⎟
⎝ N ⎠⎝
M ⎠
M
⎡
∑ ⎢∑
⎣
N
j=
1 i=
1
F(
θ φ
i,
j
) sin
θ
i
⎤
⎥
⎦
57
(5.3)