ETMSA and ITMSA Antenna for Wideband Wireless
Radiocommunication Systems
JUAN MANUEL SANCHEZ-VITE1, MARIO REYES-AYALA1,
EDGAR ALEJANDRO ANDRADE-GONZALEZ1, SANDRA CHAVEZ-SANCHEZ2, HILARIO
TERRES-PEÑA2, RENE RODRIGUEZ-RIVERA2
1Department of Electronics, 2Department of Energy
Metropolitan Autonomous University
San Pablo 180, Col. Reynosa Tamaulipas, Azcapotzalco (ZIP 02200), Mexico City
MEXICO
Abstract: - In this paper the triangular antenna is widely analyzed, calculated and simulated. The ETMSA and
ITMSA variations of the triangular variations were carried out in order compare their features. The proximity fed
of the antenna was used with the aim to improve the frequency response of the antenna in a air layer between the
ground plane and the triangular element. The computation and simulation are shown in detail and the results of
the electromagnetic field is presented using the antenna pattern and the S11 parameter, where the wideband feature
of the antennas is plotted. The design and optimization by computer demonstrate that the use of low-cost of the
PCB and the other materials can be used in the implementation of the proximity fed triangular antenna and using
an inexpensive manufacturing process.
Key-Words: - Microstrip antenna, mobile radiocommunication, higher modes, broadband antenna, antenna
bandwidth, equilateral triangular antenna, return losses.
Received: July 27, 2021. Revised: March 12, 2022. Accepted: April 15, 2022. Published: May 6, 2022.
1 Introduction
Due to their main features plane or microstrip
antennas has been employed in mobile radio
communication, because a thin geometry is more
compatible with handset terminals [1]-[10]. The main
limitation of these sort of antennas is their bandwidth
inherent limitation [8]-[12]. Nevertheless, that set of
antennas are quite simple and do not require
expensive or complex manufacturing process [11]-
[18].
A lot of structures have been probed with the aim
to obtain a wideband planar antenna, examples of
these are: defected rectangular or circular microstrip
patch antennas, [19]-[25]
Symmetric triangular antennas are related to
higher bandwidths than rectangular patches, because
this structure can be improved adding slots in their
triangular main element [9], [10].
The isosceles triangular structure is widely
analyzed in this work. Some variations of the
triangular structures like ETMSA (Equilateral
Triangular Microstrip Antenna) or ITMSA (Isosceles
Triangular Microstrip Antenna) are calculated and
simulated. Besides, the structures are improved using
linear and U slots increasing the frequency response
and employing a proximity feeder, in order to
increase their matching interval.
Another contribution in this paper, is the
presentation of design and simulation of the ETMSA
and ITMSA antennas for L-band applications with a
low-cost PCB (Printed Circuit Board). Finally, the
analysis in temperature and the effect of a plastic
enclosure are included for the implementation of the
antenna.
The simulations of this article were carried out
using Ansys HFSS (High Frequency Structure
Simulator), which employs a FEM (Finite Element
Method) algorithm to solve the Maxwell equations.
2 Design Procedure of the Equilateral
Triangular Antenna
In this section, the mathematical model of the
triangular antennas and its computation are presented
in detail [1], [2], [4].
The Figure 1 shows the triangular geometry of the
ETMSA and ITMSA antennas, where the second one
involves a isosceles triangle.
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DOI: 10.37394/23204.2022.21.13
Juan Manuel Sanchez-Vite,
Mario Reyes-Ayala, Edgar Alejandro
Andrade-Gonzalez, Sandra Chavez-Sanchez,
Hilario Terres-Peña, Rene Rodriguez-Rivera
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(a)
(b)
Fig.1 Geometry of Triangular Antennas with
proximity feeder (a) Top view, (b) Side view.
The electric field distribution is calculated using
the equations (1) and (2), where A is a constant; and,
m,n,l determine the mode of the field.
(1)
(2)
The corresponding magnetic field distribution is
obtained using the equation (3), where
is the
permeability, H/m;
is the permittivity, F/m; and,
is the angular frequency, rad/s.
(3)
The solution of the electromagnetic field involves
the resonance frequency of the triangular element in
the m,n,l mode in the x,y,z axes in the cartesian
coordinated system. This frequency can be
determined using the equation (4), where a is the size
of the triangular antenna, m; c is the phase velocity,
m/s; and,
r is the dielectric constant.
(4)
It is necessary to consider the computation of the
effective length of the triangular element because the
radiation in a two different media. It is very well
known the main approximation of the effective
length, as is shown in the equation (5).
(5)
The effective dielectric constant of the PCB is
determined by equation (6) where
eff is the effective
dielectric constant; h is the thickness of the dielectric
layer of the PCB, m; and, a is the size of the triangular
antenna, m.
(6)
The design procedure of the triangular antenna
was calculated using a PCB with a standard thickness
equal to 1.588 mm and a FR-4 substrate with a
dielectric constant approximately equal to 4.4.
The use of the dominant mode TM01 of the
ETMSA an ITMSA antennas was taken in
consideration in the 1.17 GHz frequency band. The
variation of the
angle (that is shown in Figure 1)
can be optimized for ITMSA antenna in comparison
with an equilateral geometry of the ETMSA. The size
of the antenna is illustrated in the Table 1 where the
proximity fed is included.
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Juan Manuel Sanchez-Vite,
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Andrade-Gonzalez, Sandra Chavez-Sanchez,
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Parameter
Value
1.17 GHz
3 cm
0.2 cm
60°
8.33 cm
0.9 cm
7.2139 cm
36.0699 cm
Table 1. Dimensions of the ETMSA antenna after
the design procedure.
The design of the ITMSA antenna is illustrated in
the Table 2, where the angle of the triangle is changed
in comparison with the ETMSA antenna.
Parámetro
Valor
1.13 GHz
3 cm
0.2 cm
110°
8.33 cm
13.64707 cm
0.9 cm
4.77789 cm
2.3889 cm
Table 2. Dimensions of the ITMSA antenna
after the design procedure.
3 Results
The main results of this work are presented in this
section where the Figure 1, shows the equilateral
variation of the triangular antenna ETMSA. In the
side part of this figure the proximity fed is under the
triangular radiator [32]-[40].
Fig.2 Model of the ETMSA antenna in HFSS.
The frequency response of the ETMSA antenna is
shown in the Figure 3, where the resonance frequency
is approximately equal to 1.17 GHz.
Fig.3 S11 of the ETMSA.
The antenna pattern of the ETMSA antenna is
illustrated in the Figure 4, where the directivity of the
antenna is approximately equal to 5.71 dB.
Fig. 4 Antenna pattern of the ETMSA.
The optimization of the ITMSA antenna improves
the frequency response in comparison with the
ETMSA variation where the angle of the triangle
cannot be changed, see the Table 3.
Parámetro
Valor
2.35 GHz
3 cm
0.2 cm
110°
8.33 cm
13.64707 cm
0.1 cm
4.77789 cm
1.3389 cm
Table 3. Dimensions of the ITMSA antenna
after the optimization procedure.
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Juan Manuel Sanchez-Vite,
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Andrade-Gonzalez, Sandra Chavez-Sanchez,
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The optimized results obtained with the changes
illustrated in the Table 3, where focused in the
antenna matching with the return losses (S11) and the
antenna pattern.
Fig. 5. Return losses (S11) of the ITMSA antenna.
The best response of the antenna is obtained with
a LS equal to 0.1 cm where the return losses is
approximately equal to -38.584 dB.
Fig. 6. Optimization of the S11 of the ITMSA
antenna.
Similarly the antenna gain of the optimized model
of the ITMSA is illustrated in the Figure 7, where the
antenna gain is approximately equal to 5.79 dB.
Fig. 7. Antenna pattern of the optimized ITMSA
Antenna.
Building slot in the triangular element of the
ITMSA antenna is possible to obtain a better
frequency response. Using two parallel symmetric
slots, two resonance frequency are obtained (2.49
GHz and 9.76 GHz, with corresponding bandwidths
equal to 590 MHz and 1.16 GHz), see Figures 8 and
9.
Fig. 8. ITMSA antennas with regular and U slots.
Fig. 9. Antenna pattern of the optimized ITMSA
Antenna.
Finally, U-slot gives a large bandwidth to the
ITMSA antenna as it is shown in the Figure 10, where
the return losses are plotted. In this case, the
resonance frequency is equal 2.38 GHz, and the
bandwidth is approximately 1.51 GHz.
Fig. 10. Return losses of the ETMSA antenna with a
U-Slot.
4 Conclusion
The analysis, calculation and simulation of the main
two variations of the triangular antennas were carried
out. This kind of structure has a more complex
behavior in comparison with rectangular and circular
microstrip antennas.
The use of the triangular antennas (ETMSA or
ITMSA) can provide a higher bandwidth with the
other mentioned structures in the previous paragraph.
One of the most important features of the
proposed antenna is the use of a very common PCB
with a non-expensive FR-4 substrate and a standard
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thickness (h = 1.588 mm). This kind of antennas can
be built with inexpensive manufacturing process.
The ITMSA antenna is more flexible than
ETMSA because the limitation of the angle in the
triangle element. Besides, the use of slots in the
antenna improves the bandwidth in two different
ways: a U-slot can provide a bandwidth
approximately equal to 50% (a feature of UWB
antennas) and parallel slots gives two resonance
frequencies, that can be used in multichannel systems
[20]-[32].
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This work was supported by the research project
EL002-18 in the Metropolitan Autonomous
University in Mexico City.
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DOI: 10.37394/23204.2022.21.13
Juan Manuel Sanchez-Vite,
Mario Reyes-Ayala, Edgar Alejandro
Andrade-Gonzalez, Sandra Chavez-Sanchez,
Hilario Terres-Peña, Rene Rodriguez-Rivera
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