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Ultra High Frequency Panel Antenna
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Ultra High Frequency panel
antennas (UHFP antennas) are used in UHF band. UHFP antennas
consist of radiating surfaces and a reflector. They have
frequently been used in past in TV systems. Main characteristics
of UHF panel antenna are:
• Almost hemi-spherical radiation pattern,
• Reduced dimension and easier implementation than many other
UHF antennas.
WIPL-D Simulation
A WIPL-D Pro model of a UHFP antenna is shown in (Fig. 1).
Symmetry is used so only one quarter of the antenna is modeled
(Figs 2-3). Note that the dielectric cover is marked with red
colored plates, while all the metallic parts (considered to be
perfectly conducting) are colored in cyan.
The antenna consists of various
parts with different geometries. We can see that:
• Antenna is covered by a dielectric radome of a certain
thickness,
• Finite-size reflector is used,
• Coaxial cable is used for feeding the panels,
• Panels are primary radiating elements.
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Figure 1. UHFP antenna |
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Figure 2. UHFP antenna, quarter
model |
Figure 3. UHFP antenna, metallic
parts in quarter model |
Antenna gain and near fields are both
calculated at the frequency of 0.56 GHz. Antenna gain in 3D is shown in
Fig. 4. We can see that maximum gain is about 10 dB. Antenna gain in a
theta cut is shown in Fig. 5. Please note that due to the orientation of
the spherical coordinate system, theta=0° represents a cut through one
of the two symmetry planes of the antenna.
Calculated near field is shown in Fig. 6.
We can see the radiation mechanism in which the excited antenna
generates a free space EM wave which then spreads forward. We should
notice that only quarter of the antenna is shown in Fig. 6. Also,
radiation in back direction is small because of reflector presence.
Number of unknowns, memory requirements
and simulation time at a single frequency are given in Tab. 1. Computer used for these calculations is Intel® Core2 Quad @ 2.83 GHz clock.
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Figure 4. Radiation pattern in 3D |
Figure 5. Radiation pattern in
theta cut |
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Figure 6. Near field |
Table 1. Analysis characteristics
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No. of unknowns |
Memory [MB] |
Time [sec] |
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353 |
1 |
<1 |
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Conclusion
The panel antenna presented here consists of several geometrical shapes
such as: radiating metallic panels, coaxial feeding line, finite-size
reflector, dielectric radome (cover). This demands application of a
versatile simulation tool to efficiently estimate the antenna
performance. The state-of-the-art general purpose 3D EM solver WIPL-D
Pro successfully simulates this antenna for only 4 seconds.
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