Received: 22 March 2022 Revised: 16 May 2022 Accepted: 30 August 2022 IET Communications

DOI: 10.1049/cmu2.12499

ORIGINAL RESEARCH

Compact planar magneto-electric dipole-like circularly polarized

antenna

Arvind Kumar1 Ayman A. Althuwayb2 Divya Chaturvedi3 Rajkishor Kumar4

Farnaz Ahmadfard5

1
Department of Electronics and Communication Abstract
Engineering, Visvesvaraya National Institute of
A novel circularly polarized (CP) substrate integrated magneto-electric dipole (MED)
Technology, Nagpur, Maharashtra, India
2
antenna has been designed for appropriate wireless communication. The antenna com-
Department of Electrical Engineering, College of
Engineering, Jouf University, Sakaka, Aljouf, Saudi
prises two printed radiating arc-shaped patches and a feeding strip on top, two rows of
Arabia embedded metallic vias, and a ground plane. A coax probe is used to excite the patches
3
Department of Electronics and Communication and via rows simultaneously with the help of a printed feeding strip. Finally, the antenna
Engineering, SRM University AP, Amravati, India design has been prototyped and its performance experimentally was verified in terms of
4
School of Electronics Engineering, Vellore Institute impedance bandwidth, axial-ratio (AR), gain, efficiency, and radiation patterns. The mea-
of Technology, Vellore, India sured impedance bandwidth (under −10 dB) and AR bandwidth (under 3 dB) are 6.15–7.01
5
School of Electrical and Computer Engineering, (13%) GHz and 6.24–6.40 (2.53%) GHz respectively. Typically, the measured gain value
Shiraz University, Shiraz, Iran within 3-dB AR bandwidth at 6.3 GHz is 4.5 dBic with average measured in-band antenna
efficiency of 85.2%. Moreover, the proposed antenna shows an acceptable agreement with
Correspondence
predicted counterparts, including unidirectional radiation patterns.
Farnaz Ahmadfard, School of Electrical and
Computer Engineering Shiraz University, Shiraz,
Iran.
Email: fahmadfard@gmail.com

1 INTRODUCTION polarization, and remarkably, consistent in-band antenna gain

feature [4–7].
Technologically intelligent wireless communication system However, the conventional MED antenna possesses a high-
demands compact low-profile antennas accomplishing some profile, that is, 0.25λo and towering assembly [4, 5]. The height
stringent requirements, such as wide operating frequency range, of MED antennas was significantly reduced by using a folded
and stabilized gain characteristics with unidirectional-uniform dipole structure in [6] and with dielectric loading in [7]. Further-
radiation patterns [1]. Recently, circularly polarized (CP) anten- more, multi-layered substrate-integrated MED antennas were
nas have been extensively employed in Wireless Local Area presented for millimetre-wave/ sub-millimetre wave applica-
Network (WLAN), Worldwide Interoperability for Microwave tions [8–14]. But, multi-layer substrate-based MED antenna
Access (WiMAX), satellite services and wireless power trans- needs a precise alignment to prevent the air-gap effect between
mission because of their robustness against the multipath two dielectric layers and increases fabrication complexity. The
effect, and immunity to polarization mismatch and Faraday design of a single-layered, printed circuit board (PCB) based CP
rotation [2, 3]. Due to the incredible evolution in minia- MED antenna could be promising due to its low footprints and
turized electronics gadgets, innovative designs of compact straightforward integration with RF front-end circuits. Recently,
and low-foot-printed CP antenna design remain a challenging MED CP antenna with a small footprint (single-layer substrate)
issue for antenna engineers. Recently, magneto-electric dipole was demonstrated in [15]. Bandwidth-enhanced CP magneto-
(MED) antennas have been extensively investigated, particu- electric dipole antenna for millimetre-wave applications is
larly in base stations (BS) applications, as they characterize the designed in [16]. It comprises a bowtie-shape aperture and a pair
symmetrical radiation patterns, ample bandwidth, good cross- of vertical metallic posts, which are functioned as the magnetic

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is
properly cited.
© 2022 The Authors. IET Communications published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology.

2448 wileyonlinelibrary.com/iet-com IET Commun. 2022;16:2448–2453.

KUMAR ET AL. 2449

FIGURE 2 Current density vector at different phases at a 6.23 GHz

rows of embedded metallic vias act as magnetic dipoles. These

vias electrically short the upper and bottom copper planes. The
dimensions of the metallic posts, diameter (d), and pitch distance
(s) are chosen in a manner, that delivers very less energy leak
from discrete gaps. Moreover, it must satisfy the empirical rela-
tion: d ∕s ≥ 0.5 and d ∕𝜆o ≤ 0.1(𝜆o is the free space wavelength)
and behave as vertical walls [19–21]. Optimally, the via-diameter
and pitch distance are chosen as 0.6 and 0.9 mm [22]. The metal-
lic vias rows are customized as close as to the inner corner of the
FIGURE 1 Detailed geometrical views and antenna dimension values of metallic patches. When the antenna is excited by a probe, energy
the proposed design gets coupled to rows of metallic vias and printed patches at the
same time with the help of a feeding strip. Thus, the electric
and magnetic dipoles generate two resonances in the close vicin-
dipole, and a pair of metallic patches, which are short-circuited ity which effectively leads to wide impedance bandwidth below
by a pair of vertical metallic posts and can realize electric dipole −10 dB. The coupling gap between the patch and feeding strip
radiation. A CP magnetoelectric dipole antenna array is pro- is optimized to 0.4 mm. The input impedance characteristics of
posed in [17], where, a novel substrate integrated waveguide the proposed MED antenna are determined by tuning the loca-
(SIW) to coaxial transition (SCT) was designed to connect the tion of the probe on the feeding strip. The annular arc-shaped
lightning-shaped magnetoelectric dipole antenna element and a (curved) patches are placed in a self-complementary manner
SIW feeding network. A polarization-reconfigurable, aperture- along the broad side of the feeding strip. The curved patches
coupled magnetoelectric dipole antenna was proposed in [18]. excite with a phase difference of 90o with the same magnitude
Electronically controlling the state of switches between square which leads to a circularly polarized (CP) wave. Far-field radia-
patches and an additional strip of the antenna, provides the tion of the antenna is synthesized like a two-element array. The
switching with the polarization among one linearly polarized size of the arc-shaped patch is a quarter of a full annular ring
(LP) and two orthogonal circularly polarized states. It was with outer and inner radii of 7.75 and 1.25 mm, respectively.
noted that most of the abovementioned antennas were oper- The length of the outer curve is around 12.17 mm equating to
ating in millimetre wave frequencies. To the best of authors’ 0.5λg at the centre frequency of 6.5 GHz. Therefore, the operat-
best practice, there are limited works reported on compact and ing frequency can be tuned by simply changing the value of the
single-layered CP MED antennas. radius and input impedance can be improved by tuning the inner
Here, we propose a design of a right-handed circularly polar- radius. The proposed antenna design is modelled and optimized
ized (RHCP) substrate-integrated MED antenna with good with the help of CST MWS commercial electromagnetic simula-
radiation performance. The proposed design is fabricated on tor tool is used to model and simulate the design. The optimized
a low-profile substrate which has a capability to integrate the values are provided in Figure 1.
antenna circuitry in a single rigid package of RF front-end. To understand the sense of the CP concept, the equivalent
current density vectors on top of the proposed radiation system
for different phases are shown in Figure 2. A counterclock-
2 ANTENNA DESIGN wise rotation of the current vector is observed as time elapses.
And, this defines right-handed CP (RHCP) radiation at +z-
A detailed geometrical design sketch of the proposed MED axis. Similarly, left-handed CP (LHCP) radiation can be achieved
antenna is demonstrated in Figure 1. The antenna comprises by imaging the feeding point around the centre of the struc-
two radiating annular arc-shaped patches, two rows of embed- ture. The performance of the proposed antenna is shown in
ded metallic vias, a feeding strip and a reflector ground plane. Section 3.
The complete antenna is designed on a single-layered substrate To investigate the influence of key parameters of the antenna,
of thickness 3.0 mm. Two printed half-wave electric dipoles a parametric study is conducted and their effect on −10 dB
are formed by annular arc-shaped patches whereas a couple of impedance bandwidth, gain and AR bandwidth is observed. The
2450 KUMAR ET AL.

0 10 0 10

RHCP Gain, (dBiC)

RHCP Gain, (dBiC)

5 5

S11, (dB)
-10
S11, (dB)

-10
0 0
-20 -20
-5 -5

-30 -10 -30 -10

5.5 6.0 6.5 7.0 7.5 5.5 6.0 6.5 7.0 7.5 5.5 6.0 6.5 7.0 7.5
5.5 6.0 6.5 7.0 7.5 Frequency, (GHz)
Frequency, (GHz) Frequency, (GHz) Frequency, (GHz)

(b) (a) (b)

(a)
12 12
Axial Ratio, (dB)

Axial Ratio, (dB)

9 wp = 5.5 mm 9
a = 5.2 mm
6 wp = 6.5 mm 6 a = 5.4 mm
wp = 7.5mm a = 5.6 mm
3 3

0 0
5.5 6.0 6.5 7.0 7.5 5.5 6.0 6.5 7.0 7.5
Frequency, (GHz) Frequency, (GHz)
(c) (c)

FIGURE 3 Simulated results for different values of parameter ‘wp ’: FIGURE 4 Simulated results for different values of parameter ‘a’:
(a) Reflection coefficient (S11 ), (b) gain, and (c) axial-ratio (AR) (a) Reflection coefficient (S11 ), (b) gain and (c) axial-ratio (AR)

effect of the parameter ‘wp ’ (i.e. the width of the patch) on the
antenna performance is shown in Figure 3. The outer circum-
ference of the proposed patch can be changed by increasing the
outer radius, this helps in the shifting of the centre frequency.
As the value of the ‘wp ’ increases, the size of the electric dipole
(patch) increases and vice-versa. Thus, the resonant frequency
can be tuned at the lower and higher end of the desired fre-
quency in sub-6 GHz band as shown in Figure 3a. Moreover,
the operating bandwidth also can be controlled by tuning this
parameter, while gain and AR are affected at minimum extends
as shown in Figure 3b,c. Probe-feed location on the metallic
strip plays a critical role in matching the proper input impedance FIGURE 5 Prototyped sample of the proposed antenna
due to its function of coupling the electromagnetic energy. 50 Ω
input impedance on the metallic strip is realized with the help of
the trial-method. c. Implant the two rows of metallic vias as close as to the inner
Figure 4 shows the influence of parameter ‘a’ on the antenna corner of patches.
performance. The parameter ‘a’ is the location of the coax- d. Use coax probe and feeding strip to excite magneto and elec-
probe on the feeding strip, and the length of this strip is tric dipoles, simultaneously (as shown in Figure 1). Tune
maintained the same as ‘wp ’ parameter. Thus, parameter ‘a’ is the feeding point and inner radius to achieve better input
optimized to tune the coax probe at 50 Ω. Also, this parame- impedance matching.
ter controls the phase difference between two curved patches.
It is noted that by mirroring the parameter ’a’ around the
centroid, LHCP radiation can be realized. Furthermore, it 3 EXPERIMENTAL RESULTS AND
is observed that the gain in above-mentioned cases remains VERIFICATIONS
consistent.
Finally, brief design steps for the proposed antenna are To confirm the expected performance of the antenna, the
summarized as: design is prototyped and results are tested experimentally. The
antenna is prototyped on dielectric material Rogers RO4003C
a. Choose the proper thickness of the dielectric substrate, (ide- as shown in the photograph (Figure 5). The input impedance
ally height of the magneto-electric dipole antenna should matching and far-field radiation patterns are tested by Anritsu
be 𝜆g ∕4, however larger thickness may lead to the excita- (Shock-Line MS46122B series) network analyzer and an ane-
tion of unwanted surface waves). Here, 𝜆g is the guiding choic chamber. Simulated and measured reflection coefficients
wavelength at the centre frequency of the operating band. (S-parameter) of the antenna are plotted in Figure 6. The sim-
b. Design two identical annular arc-shaped dipoles. Opt the ulated S-parameter shows that the bandwidth of the antenna
length of the outer arc as 0.5𝜆g . is extending from 6.10 to 6.90 GHz, 815 MHz, while the
KUMAR ET AL. 2451

10 10
Sim. RHCP
5 5 Sim. LHCP
Meas. RHCP
0 0 Meas. LHCP

RHCP Gain, dBiC

0 0
S-Parameter, dB

-5 -5 0 0

-10 -10 -10 -10

-15 -15 -20 -20

-20 -20 270 -30 90 270 -30 90

-25 Blue: Simulated -25

Red: Measured
-30 -30
5.50 5.75 6.00 6.25 6.50 6.75 7.00 7.25 7.50
Frequency, GHz 180 180
(a) (b)
FIGURE 6 Measured vs simulated S-Parameters and RHCP gain
performance of the proposed antenna FIGURE 8 Measured vs simulated radiation patterns at 6.3 GHz:
(a) xz-plane and (b) yz-plane

100 40
95 measurement is referenced back to the phase and magnitude of
35
90 the source. If we use the same measurement antenna (e.g. a horn
85 30
antenna) and rotate it 90o to capture each component, then
Antenna efficiency, %

80
Axial ratio, dB

25 we can generally ignore calibration-related issues. Once the two

75
linearly polarized components of the field are obtained, need
70 20
65
to convert from linearly polarized components to elliptically
15 polarized components. That will provide a major and minor
60
55 10 component of the field which can then be used to evaluate
Blue: Simulated axial ratio. The measured minimum AR is 0.75 dB at 6.3 GHz.
50
Red: Measured 5
45 The simulated and measured AR 3-dB bandwidth is ranging
40 0 from 6.03 to 6.35 GHz and 6.24 to 6.40 GHz (2.5%), respec-
5.50 5.75 6.00 6.25 6.50 6.75 7.00 7.25 7.50 tively. Normalized far-field radiation pattern measurements are
Frequency, GHz performed at a frequency of 6.3 GHz. Figure 8 clearly shows
co-polarisation (RHCP) and cross-polarization (LHCP) radia-
FIGURE 7 Measured vs simulated antenna efficiency and axial-ratio (AR)
tion patterns in two principal cut-planes of xz and yz-plane.
of the proposed antenna
The measured and simulated radiation patterns mutually agreed
well with each other. The measured LHCP below the RHCP
measured impedance bandwidth is about 13% from 6.15 to levels by around 11 dB. Moreover, the patterns are quite iden-
7.01 GHz, 860 MHz with two resonances occurring around 6.3 tical in both the cut-planes, similar to the conventional metallic
and 6.8 GHz. A small drift can be observed in the resonant MED antennas [4, 5, 23–25]. Furthermore, manual change of
frequencies towards the right, which is attributed to fabrica- the measurement planes may also lead to a small deviation from
tion tolerances. Gain versus frequency response is also shown the simulated results. The bottom ground plane hinders the
in Figure 6. The simulated in-band gain performance of the backside radiation which leads to unidirectional radiation. The
antenna is stable and shows good stop-band response out of measured front-to-back-ratio (FTBR) is better than 14.3 dB.
the operating frequency range of the proposed design. Typi- To elucidate the performance of the proposed antenna, a
cally, the measured RHCP gain value within 3-dB AR bandwidth comparative study with recent singly-fed substrate-integrated
is around 4.5 dBic. Figure 7 shows antenna efficiency and AR MED antennas is summarized in Table 1. Many substrate
versus frequency plot. The simulated antenna efficiency within integrated MED antennas are realized and fabricated using
−10 dB bandwidth is around 95%, and the average measured standard PCB Technology [14, 15], which are realized by incor-
efficiency is better than 85.2 % in the operating band. However, porating multi-layered substrate configuration. Multi-layered
it is not as good as the simulated ones. This is mainly due to the configuration increases the fabrication complexity. Addition-
errors in measurement set-up and parasitic losses which were ally, they need a precise alignment or fixing with the help of
not considered in the simulation model. The measurement of prepregs or nylon screws. The proposed design shows improved
the axial ratio was done as suggested in [26]. To measure the impedance bandwidth and gain performance with preserv-
axial ratio, two orthogonal polarizations normal to the propaga- ing unidirectional radiation patterns against [14]. Additionally,
tion direction are measured, by calculating both the magnitude the proposed design possesses a more compact solution than
and phase relationship of the two signals. In the case of our [14] as a circularly polarised antenna. However, it shows rel-
antenna pattern measurement, we have used a VNA, since every atively poor axial-ratio bandwidth. Whereas, compared to 3D
2452 KUMAR ET AL.

TABLE 1 Substrate integrated MED antenna performance comparison

Properties [12] [13] [14] Here

BW in GHz, (%) 4.98–6.01 (18) 5.01–5.92 (13) 5.63–5.88 (4.3) 6.15–7.01 (13)
height (h) 6.0 mm 5.0 mm 2.0 mm 3.0 mm
(λo ) (0.111λo ) (0.091λo ) (0.039λo ) (0.050λo )
ARBW (%) – – 4.3 2.5
Peak gain 6.8 6.4 2.4 4.5
dBi dBi dBic dBic
Cross pol. 22 >15 dB 10 ∼12 dB
Effi. (%) 81 – 62 85.2
Size (mm3 ) 36 × 36 × 6.0 37 × 37 × 5.0 90 × 17 × 2.0 36 × 36 × 3.0
Remarks Multilayer PCBs; Complex Multilayer PCBs; Complex Single-layer PCB; simple Single layer PCB; simple
fabrication fabrication design, Narrow impedance design; wide impedance
BW band BW

λo is free space wavelength at centre frequency.

magneto-electric dipole antennas [12, 13], the design maintains DATA AVAILABILITY STATEMENT
a low-profile and planar structure of 0.05𝜆o in thickness. Data sharing not applicable – no new data generated Data shar-
The originality of this work is to introduce a design to ing is not applicable to this article as no new data were created
decrease the height of a planar MED antenna. This design is or analyzed in this study.
simpler than other designs available in the literature [14, 15,
23–25]. The proposed novel MED antenna also can be easily ORCID
realized by existing PCB on the single-layered substrate. Fur- Arvind Kumar https://orcid.org/0000-0002-9695-4399
thermore, the compact size (36 mm × 36 mm) of the antenna Ayman A. Althuwayb https://orcid.org/0000-0001-5160-
is encouraging towards realizing planar integration with wireless 5016
communication transceivers on restricted radio-frequency ele- Divya Chaturvedi https://orcid.org/0000-0003-0141-2034
ments space. The proposed design can be easily extended to a Rajkishor Kumar https://orcid.org/0000-0002-6140-1241
wideband CP array by opting suitable corporate feeding system. Farnaz Ahmadfard https://orcid.org/0000-0002-2962-3389
Besides, our proposed antenna is one of the good candidates
that could be prepared for LTCC fabrication when the operat- REFERENCES
ing frequency of the antenna moves to a higher frequency range 1. Althuwayb, A.A., et al.: Design of half-mode substrate integrated cavity
such as millimetre-wave frequency or THz. inspired dual-band antenna. Int. J. RF Microwave Comput. Aided Eng.
31(2), e22520 (2021)
2. Kumar, A., Raghavan, S.: Broadband dual-circularly polarised SIW cavity
antenna using a stacked structure. Electron. Lett. 53(17), 1171–1172 (2017)
4 CONCLUSION 3. Kumar, A., Chaturvedi, D., Raghavan, S.: SIW cavity-backed circu-
larly polarized square ring slot antenna with wide axial-ratio bandwidth.
Here, a novel design of a profile of 3 mm CP MED antenna AEU-Int. J. Electron. Commun. 94, 122–127 (2018)
has been demonstrated and outcomes are investigated. The 4. Gupta, S., Jiang, L.J., Caloz, C.: Magnetoelectric dipole antenna arrays.
IEEE Trans. Antennas Propag. 62(7), 3613–3622 (2014)
antenna possesses a compact size and single-layered configura-
5. An, WX., Wong, H., Lau, K.L., Li, S.F., Xue, Q.: Design of broadband
tion with a single probe feed. The antenna is prototyped and dual-band dipole for base station antenna. IEEE Trans. Antennas Propag.
tested, showing 13% impedance bandwidth, 2.5% AR band- 60(3), 1592–1595 (2011)
width, and 4.5 dBic peak gain with better than 85% efficiency. 6. Ge, L., Luk, K.M.: A magneto-electric dipole antenna with low-profile and
The antenna is capable to offer unidirectional and stable radi- simple structure. IEEE Antennas Wirel. Propag. Lett. 140–142 (2013)
7. Siu, L., Wong, H., Luk, K.-M.: A dual-polarized magneto-electric dipole
ation characteristics across the operating band. This design
with dielectric loading. IEEE Trans. Antennas Propag. 57(3), 616–623
could be suitable for light-weighted wireless transceivers used (2009)
in satellite communication or sub-6 GHz band. 8. Li, Y., Luk, K.-M.: 60-GHz dual-polarized two-dimensional switch-beam
wideband antenna array of aperture-coupled magneto-electric dipoles.
CONFLICT OF INTEREST IEEE Trans. Antennas Propag. 64(2), 554–563 (2015)
9. Hao, Z.-C., Yuan, Q., Li, B.-W., Luo, G.Q.: Wideband W-band substrate-
The authors declare no conflict of interest.
integrated waveguide magnetoelectric (ME) dipole array antenna. IEEE
Trans. Antennas Propag. 66(6), 3195–3200 (2018)
FUNDING INFORMATION 10. Xu, J., Hong, W., Hao Jiang, Z., Zhang, H.: Low-cost millimeter-wave cir-
This work was not supported by any agency. cularly polarized planar integrated magneto-electric dipole and its arrays
KUMAR ET AL. 2453

with low-profile feeding structures. IEEE Antennas Wirel. Propag. Lett. 20. Chaturvedi, D., Kumar, A., Raghavan, S.: Wideband HMSIW-based slot-
19(8), 1400–1404 (2020) ted antenna for wireless fidelity application. IET Microwaves Antennas
11. Sun, Y., He, Y., He, W., Zhang, L., Wong, S.W.: A wideband circularly Propag. 13(2), 258–262 (2019)
polarized cross-dipole antenna with L-shape slots. In: 2020 IEEE Inter- 21. Kumar, A., Raghavan, S.: A design of miniaturized half-mode SIW cav-
national Symposium on Antennas and Propagation and North American ity backed antenna. In: 2016 IEEE Indian Antenna Week (IAW 2016),
Radio Science Meeting, Montréal, pp. 673–674 (2020) Madurai, India pp. 4–7 (2016)
12. Lai, H.W., Wong, H.: Substrate integrated magneto-electric dipole antenna 22. Kumar, A., et al.: Design of antenna-multiplexer for seamless on-body
for 5G Wi-Fi. IEEE Trans. Antennas Propag. 63(2), 870–874 (2014) internet of medical things (IoMT) connectivity. IEEE Trans. Circuits Syst.
13. Shuai, C.-Y., Wang, G.-M.: Substrate-integrated low-profile unidirectional Express Briefs. 69(8), 3395–3399 (2022), https://doi.org/10.1109/TCSII.
antenna. IET Microwaves Antennas Propag. 12(2), 185–189 (2017) 2022.3170513.
14. Liu, J., Li, Y., Liang, Z., Long, Y.: A planar quasi-magnetic–electric circu- 23. Liang, W., et al.: Circularly polarised magneto-electric dipole antenna.
larly polarized antenna. IEEE Trans. Antennas Propag. 64(6), 2108–2114 Electron. Lett. 50(14), 976–978 (2014)
(2016) 24. Tao, J., Feng, Q.: Dual-band magnetoelectric dipole antenna with dual-
15. Cao, W., Wang, Q., Qian, Z., Shi, S., Jin, J., Ding, K., Zhang, B.: Gain sense circularly polarized character. IEEE Trans. Antennas Propag. 65(11),
enhancement for wideband CP ME-dipole antenna by loading with spi- 5677–5685 (2017)
ral strip in Ku-band. IEEE Trans. Antennas Propag. 66(2), 962–966 25. Kang, K., Shi, Y., Liang, C.H.: A wideband circularly polarized mag-
(2017) netoelectric dipole antenna. IEEE Antennas Wirel. Propag. Lett. 16,
16. Wang, Y.-F., Wu, B., Zhang, N., Zhao, Y.-T., Su, T.: Wideband circu- 1647–1650 (2017)
larly polarized magneto-electric dipole $1∖times2 $ antenna array for 26. Toh, B.Y., Cahill, R., Fusco, V.F.: Understanding and measuring circular
millimeter-wave applications. IEEE Access 8, 27516–27523 (2020) polarization. IEEE Trans. Educ. 46(3), 313–318 (2000)
17. Feng, B., Lai, J., Chung, K.L., Chen, T.-Y., Liu, Y.: A compact wide-
band circularly polarized magneto-electric dipole antenna array for
5G millimeter-wave application. IEEE Trans. Antennas Propag. 68(9),
6838–6843 (2020) How to cite this article: Kumar, A., Althuwayb, A.A.,
18. Ge, L., Yang, X., Zhang, D., Li, M., Wong, H.: Polarization-reconfigurable Chaturvedi, D., Kumar, R., Ahmadfard, F.: Compact
magnetoelectric dipole antenna for 5G Wi-Fi. IEEE Antennas Wirel. planar magneto-electric dipole-like circularly polarized
Propag. Lett. 16, 1504–1507 (2017)
antenna. IET Commun. 16, 2448–2453 (2022).
19. Kumar, A., Imaculate Rosaline, S.: Hybrid half-mode SIW cavity-backed
diplex antenna for on-body transceiver applications. Appl. Phys. A. https://doi.org/10.1049/cmu2.12499
127(11), 1–7 (2021)