2020 3rd International Conference on Computing, Mathematics and Engineering Technologies – iCoMET 2020

An integrated 4G Array with mm-wave 5G MIMO

Antenna for Future Mobile applications
Mahnoor Khalid Syeda Iffat Naqvi
Telecommunication Engineering Department Telecommunication Engineering Department
University of Engineering & Technology University of Engineering & Technology
Taxila, Pakistan Taxila, Pakistan
mahnoor13tc@gmail.com Iffat.naqvi@uettaxila.edu

Yasar Amin Hannu Tenhunen

Telecommunication Engineering Department Department of Electronic Systems
University of Engineering & Technology KTH
Taxila, Pakistan Stockholm, Sweden
Yasar.amin@uettaxila.edu.pk hannu@kth.se

Abstract— This work presents an antenna system with system is one of the major technologies that can enhance
integrated approach for 4G LTE and high frequency (mm- bandwidth and antenna gain for current and future wireless
wave) 5G communication systems. The proposed antenna networks, thus can deal with rain attenuation to overcome
solution comprises of two-element antenna array module for atmospheric losses [6]. MIMO technology also has key
sub-6 GHz 4G bands, and MIMO antenna system resonating
importance in current and future wireless devices due to
at 5G mm-wave frequency band. The array elements are
excited by a feed network based on the T-junction power multi-channel reception and high throughput. To fulfill the
divider or combiner. The proposed design has overall necessities of current and future wireless communication
dimensions of 135×77×1.575 mm3. The 4G antenna module is systems, integrated 4G and 5G antenna array systems with
placed at the top side of the board, while the four 5G MIMO compact configuration are required for small handheld and
antennas are loaded on the longer edges of the board. The 4G mobile devices.
band obtained is ranging from 2.2-4.9 GHz. Whereas, the 5G Several antenna designs are reported in the literature for 4G
antennas cover the 26-28.8 GHz band, which is a potential LTE applications [7-10]. An LTE/WWAN antenna for
band for future 5G wireless applications. Moreover, the peak smartphone application is reported [7] with overall
gain obtained by the 4G antenna module is 7.31 dB while 9.21
dimensions of 115×60×0.8 mm3. The antenna achieves two
dB by 5G antennas. In addition, the MIMO performance of the
proposed 5G antennas is also investigated. Hence, the simple wide bands of 0.325 GHz and 1.165 GHz. A wideband
structure, compactness, and performance of the proposed antenna with an overall size of 115×60×0.8 mm3 is
design ascertain it to be suitable for existing and forthcoming proposed for 4G handheld device with maximum achieved
handheld devices. bandwidth of 1.28 GHz [8]. A multiband antenna is
presented for LTE/WWAN mobile phone applications [9].
Keywords— Array antenna, MIMO, integrated 4G/5G, sub-6 The antenna is designed on board size of 106 × 45×0.8 mm3
GHz bands, mm-wave, handheld devices. with a wide bandwidth of 0.7 GHz. In [10], the LTE
smartphone antenna with an internal matching circuit is
I. INTRODUCTION presented with a maximum bandwidth of 2.01 GHz. The
overall geometrical size of the proposed design is 111 ×
With the advancement of technology, there is a rapid 50×1.6 mm3.The 4G LTE antennas reported in [7-10] are
increase in the demand for wireless communication systems difficult to integrate into to small handheld devices and
with wider bandwidths and high data rates [1-2]. In order to mobile terminals due to complicated structure and large
meet the continuously increasing data rate requirements in dimensions of single element antenna.
communication systems, 4G LTE commercial and 5G wireless networks for wireless communication has
broadband standards are implemented in modern-day drawn attention after the increasing demand for high data
wireless systems to fulfill the need of high data rates. After rates. Lately, various antenna designs have been reported for
LTE commercialization, researchers commenced their 5G wireless communication systems [11-15]. A grid-based
efforts for forthcoming 5G broadband wireless and mobile antenna array with 23 elements is presented in [11]
communications. Intensive data processing capability and operating at 15 GHz for 5G applications with 2.1 GHz
high system throughput are the requirements of the wireless bandwidth and a peak gain of 14.4 dBi. An 8×8 MIMO
devices operating at 5G sub-6 GHz and mm-wave frequency based 5G antenna is reported in [12] with a maximum
bands. Hence, this impending wireless standard necessitates bandwidth of 750 MHz and gain value of 9.6 dB. In [13] 4
large bandwidth [3-4]. In addition to the wide bandwidth, PIFA array antenna with 4×4 MIMO configuration is
gain of the antenna should be high to deal with the rain reported having a bandwidth of 1 GHz at 28 GHz with a
attenuations at higher frequencies [5]. The antenna array

978-1-7281-4970-7/20/$31.00 ©2020 IEEE

peak gain of 12 dBi. In [14] mm-wave beam steerable array
antenna is reported resonating with 2.5 GHz bandwidth. In
[15] MIMO antenna is reported operating at 24 GHz with a
bandwidth of 800 MHz with 6dB peak gain.
In all the above-reported work, the reported designs are
suitable for either existing 4th generation or forthcoming 5th
generation wireless applications. With the increasing
demands of the digital era, the need for a system will rise
subsequently that is friendly with both technologies.
However, to introduce integrated systems in handheld
devices is challenging due to size limitations and increased
coupling current between antenna elements [16]. Thus,
sufficient isolation and compactness are listed among the
integrated designs challenges. Recently, integrated antenna
systems are reported both 4th and 5th generation wireless
standards for handheld devices [17-22]. In [17], an 8×8 (a) (b)
MIMO antenna array is demonstrated covering LTE
2300/2500 and C band for 5G applications. A 2×2 MIMO Fig. 1. 4G/5G Integrated System (a) Top view (b) Back view
antenna for 4G LTE and a planar connected array for 5G
applications is reported in [18,19], respectively. In [20], the
connected array antenna along with MIMO configuration is
proposed for 4G/5G applications with 1.5 GHz combined
bandwidth for all 4G obtained bands. Whereas, the
maximum bandwidth obtained for 5G bands is 1 GHz. In
[21] 4G/5G integrated design is proposed with a bandwidth
of 1.24. Another 4G/5G antenna system is reported in [22]
with wide bands for 4G and 5G mm wave applications.
The work proposed in this article is an integrated antenna
array supporting 4G LTE and 5G handheld applications. A Fig. 2. 4G LTE Single Element Design
significant amount of bandwidth gain and isolation between B. 4G Array Design
the antenna modules is achieved for the design
demonstrated in this work. The significance of the proposed Afterward, single element design is evolved to antenna
antenna array is evident through the reported. This makes array as shown in Fig. 3. The design consists of a two-
the reported design suitable for existing and forthcoming element array excited by parallel feeding network based
wireless communication applications. on 1×2 junction power divider or Combiner. The two
antenna elements are separated by 6 mm which is
II. ANTENNA STRUCTURE approximately λ/12 at 3.6 GHz. Two rectangular slots are
Fig. 1. shows the geometry for the proposed integrated loaded at the bottom layer to enhance impedance
antenna configuration. The modeling of the design is carried matching.
out on 1.575 mm thick R05880 substrate with εr = 2.2. The
simulation and optimization are carried out using CST
Microwave Studio. The design comprises of antenna array
covering 4G LTE and 5G lower bands integrated with 5G
MIMO array antennas operating at n257 mm-wave band.
The overall dimensions of the proposed design are 135
mm×77 mm×1.575 mm. In Fig. 1(a), the placement of the
antenna arrays is illustrated, whereas in Fig. (b) the ground
plane with rectangular slots is shown. The detailed
progression of the design is provided below.
Fig. 3. 4G LTE Antenna Array Design
A. 4G Single Element Design
The modeling is started from 4G LTE single element C. 5G Single Element Design
designing. Firstly, a rectangular patch is designed from the The design proceeds with modeling a single element
numerical analysis given in [23]. In order to obtain the antenna for mm-wave frequencies. A hexagonal edge-
required specification, the patch is optimized into the final mounted microstrip line patch antenna is obtained firstly by
shape by adding rectangular slots and slits with blended numerical analysis [24]. Afterward, the design is optimized
edges as shown in Fig.2. by introducing slots in feed and patch and thus wideband is
 III. RESULTS AND DISCUSSIONS
The working mechanism and radiation behavior of the
proposed antenna system are analyzed and demonstrated in
the following sections.
A. Scattering Parameters
The simulated S11 plot for the 4G single element and array
configuration before and after integration is illustrated in
Fig 6. The 4G LTE single element is resonating at 3.3 GHz
with 700 MHz bandwidth, while the two-element array is
covering 2.8-4.7 GHz band (-10 dB bandwidth) thus
supporting 4G LTE and 5G lower bands in wireless
Fig. 4. 5G Single Element Design communication applications. After integrating both antenna
modules, the performance of the 4G antenna array is
investigated. It is observed that bandwidth is enhanced in
obtained. The optimized patch for 5G mm-wave is shown in the integrated system for Ant-1, consequently covering 2.2-
Fig. 4. 4.9 GHz frequency band with a bandwidth of 2.7 GHz.
D. 5G Array Antenna Design
The design is further proceeded by modeling of 5G antenna
array system as shown in Fig. 5. The configuration is a two-
element array antenna that is excited by a parallel feeding
network. The planar assembly of the antenna promises the
ease of integration with RF and microwave circuits. Both
antenna elements are separated by 3.8 mm which is
approximately λ/3 at 27.3 GHz to achieve the desired
compactness.

Fig. 6 Reflection Coefficient Curves of 4G Antenna Before and After

Integration

Fig. 7. illustrates the reflection coefficient plots for the 5G

antennas before and after integration. The plot demonstrates
Fig. 5. 5G Antenna Array Design that before integrating with the 4G antenna array, the single
element of 5G is resonating at 27.3 GHz with a bandwidth
E. 4G/5G Integrated Antenna Design of 1.0 GHz, on the other hand, the 5G array antenna module
is resonating from 26-29 GHz with 3.0 GHz bandwidth at -
The last step in designing is followed, the 4G/5G antenna 10 dB reference. The investigation of results after
system is to integrate both 4G and 5G antenna modules and integrating 4G and 5G antenna modules exhibits 0.12 GHz
to analyze the performance of the integrated system. bandwidth reduction ranging from 26-28.82 GHz with 2.88
Moreover, in order to deal high through-put the demand of GHz obtained bandwidth. Other MIMO antennas are
5G, 4×4 5G MIMO antenna arrays are integrated with Ant-1 demonstrating identical behavior with an approximate
by placing 5G array antenna modules on the left and right bandwidth of 2.88 GHz, as evident from the reflection
side of the board. The layout of the integrated assembly is coefficient curves for Ant-2 and Ant-5 in Fig. 7. Moreover,
illustrated in Fig. 1. The suitability of the reported design is the transmission coefficient curves for the proposed MIMO
enlightened by the structural compactness and the placement antennas in Fig. 8. exhibits minimum isolation of -32 dB.
of the antenna modules for existing and forthcoming Hence, the proposed integrated antenna array system is
handheld devices [25]. suitable for both 4G and 5G current and future
communication devices and systems.
 YZ-Plane XZ-Plane

(a)

Fig. 7 Reflection Coefficient Plots of 5G mm-wave Antennas (b)

(c)

Fig. 9 2D Radiation Patterns in XZ and YZ planes of (a) Ant-1 at 3.34 GHz

(b) Ant-2 at 28 GHz (c) Ant-5 at 28 GHz

TABLE I. GAIN AND EFFICIENCY OF PROPOSED ANTENNA

Frequency (GHz) Peak Gain(dB) Efficiency (%)

2.2 3.89 82
3.3 5.76 87
4.5 7.31 93
Fig. 8 Transmission Coefficient Plots of 5G mm-wave Antennas 26 8.8 80
27.3 8.61 78
B. Radiation Patterns 28 8.93 79.83
Fig. 9. (a) shows 2D radiation patterns in YZ and XZ plane 28.5 9.21 80
for the 4G Ant1 at 3.3 GHz. It is observed that the 4G
antenna array exhibits monopole pattern. Similarly, Fig. 9.
(b) and (c) illustrates the radiational behavior of 5G MIMO D. MIMO Performance Analysis
Ant-2 and Ant-5 at 28 GHz, respectively. For 5G antennas,
To analyze the MIMO performance of the proposed 5G
directional radiation behavior is observed.
antennas, several parameters are investigated. The Envelope
C. Gain and Efficiency correlation coefficient, diversity gain, Channel capacity loss
The Gain and antenna efficiency are also analyzed to ensure and mean effective gain of the proposed design are the
the performance of the proposed antenna. The peak gain important parameters [26]. The proposed antenna ensures
obtained for the 4G antenna array is 7.31 dB, whereas for ECC below 0.03 in the entire band below the practical
5G antenna array peak gain of 9.21 dB is attained. The 4G standards as shown in Fig. 10. While DG of the system is
antenna shows a maximum efficiency of 93%, while 80% approx. 10 dB throughout the band as depicted in Fig. 11,
peak efficiency is obtained by 5G array antenna. The gain thus ascertaining the spatial diversity performance of the
and efficiency values at different operational frequencies are antenna. The channel capacity loss (CCL) of the proposed
tabulated in Table I. design is below the practical standards of 0.4 bits/Hz/s in
 TABLE II. MEAN EFFECTIVE GAIN

Frequency Mean effective gain (-dB)

(GHz) #2 #3 #4 #5
26 6.24 6.285 6.62 6.20
26.5 5.75 5.60 5.35 5.67
27 5.79 5.49 5.87 5.09
27.5 5.01 5.54 5.13 5.21
28 6.96 6.65 6.88 6.07
28.5 6.83 6.63 7.02 6.90

the entire band thus ensures the high throughput of the

system as shown in Fig.12. The Mean effective gain (MEG)
also ensure the antenna diversity performance and is below
practical standards as tabulated in Table II.
Fig.10. Envelope Correlation Coefficient of Proposed 5G MIMO Antennas
III. COMPARISON WITH RELATED WORK

The comparison with related work reported in the literature

is summarized in Table III. The proposed antenna system
shows improved performance concerning gain and
bandwidth. Moreover, the compact and planar configuration
validates the easy integration of the antenna system with the
RF & microwave circuitry. Moreover, better MIMO
performance of the reported 5G antenna system ascertains
the aptness of the design for future mm-wave wireless
applications.

TABLE III. COMPARISON WITH THE RELATED WORK

Gain ECC
Ref. Bandwidth CCL
(dB) &DG
(GHz)
Not Not
[13] 27.5-28.5 12 dBi
Fig. 11. Diversity Gain of Proposed 5G MIMO Antennas Provided Provided

1.8-2.7 Not Not

[17] <0.3
3.4-3.6 Provided Provided
1.862-3.305
5 & 9.65 Not
[18] 3.5-3.84 <0.0613
Provided
27.5-28.72
1.9-2.08
2.10-2.230
2 & 8.28 Not
[20] 3.06-3.14 <0.05
Provided
3.48-3.5
12.90-16
820-960
Not Not
[21] 1.710-2.690 <0.05
Provided Provided
3400-3600
This 2.-4.9 7.31, <0.3
<0.4
work 26-28.88 9.21 >9.95

IV. CONCLUSION

Fig.12. Channel Capacity Loss of Proposed 5G MIMO Antennas In this work, an integrated antenna system is proposed for
both 4G and 5G wireless communication applications with
wide bandwidth and significant gain. The antenna arrays for [15] A. Iqbal et al., "Electromagnetic Bandgap Backed Millimeter-Wave
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