Ultra Wide Band Elliptical Antenna
Ultra wide band elliptical (UWB elliptical) antenna is a
type of a printed antenna. It is small, simple,lightweight and economical, often used in UWBtransmitters.
UWB antenna topologies are derived from works incircular and elliptical disc monopoles. The main
characteristic of the given elliptical antenna is that it isbroadband.

In WIPL-D Pro, this antenna can be modeled in several
ways in order to diminish simulation time and memory
requirements. One can use the Symmetry feature, so
only half of the given antenna is modeled (Fig. 3), thus
saving both memory and time.
Antenna is analyzed in frequency band 2 GHz up to20 GHz.

Figure 3. UWB elliptical antenna – half model

Figure 1. UWB elliptical antenna

We will calculate S11 parameter in the entire range inorder to determine antenna operating band and toanalyze antenna matching, radiation pattern and nearfield at one frequency at which antenna is matched.
Computer used for these calculations is Intel Core2
Quad @ 2.83 GHz clock.
Parameter S11 is shown in Fig. 4. We can see that
antenna operating band is from 4 GHz up to 14 GHz(where, parameter S11 is roughly less than -10 dB).

Figure 2. UWB elliptical antenna, bottom side

WIPL-D Simulation
In WIPL-D Pro, metallic plates are colored in blue anddielectric plates are colored otherwise, so we see thatthe given antenna is printed on a finite dielectric
substrate (Fig. 1) and has no ground plane (reflector;Fig. 2), thus we expect low directivity and highradiation in both front and back directions.
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Figure 4. Parameter S11Table 1. Analysis characteristics

Antenna gain in 3D is shown in Fig. 5. We can see thatgain is low (maximum is about 4.5 dB). Also, antenna
is quasi-omni-directional (Fig. 5). Radiation pattern has
minimums in four directions in the xOy plane, which
are expected for this antenna design.

No. of unknowns

Time [sec]

2787

151

Conclusion
WIPL-D Pro is a frequency-domain software andanalyzed structure is broadband (operating from 5 GHz
up to 14 GHz). This type of simulation is usuallychallenging for frequency-domain solvers and timedomain solvers usually have much shorter simulation
times. However, we can notice that simulation time in
WIPL-D Pro is very short eventhough it was done in 21
frequencies, thanks to:•very small number of unknowns this model
requires as a result of higher order method ofmoments in combination with Edging
technique for meshing,•very fast numerical libraries implemented in
WIPL-D Pro solver that use modern CPU
architectures to full extent,•Symmetry option is used in this problem andthus, number of unknowns is halved andsimulation time decreased significantly.

Figure 5. Radiation pattern in 3D

Calculated near field is shown in Fig. 6. We can see thetransition from standing EM wave to free space EMwave. We should notice that only half of the antenna isshown in Fig. 5 because we used model symmetry.
Number of unknowns and simulation time of analysis
are given in Tab. 1.

Hence, WIPL-D Pro is probably the only
frequency-domain solver that can compete with leading
time-domain codes in terms of simulation times inUWB simulation. Results given by WIPL-D Pro andpresented here coincide well with theoretical
expectations.

Figure 6. Near fieldwww.wipl-d.com
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