Citation: Zhou, I.; Pradell, L.;
Villegas, J.M.; Vidal, N.; Albert, M.;
Jofre, L.; Romeu, J. Microstrip-Fed
3D-Printed H-Sectorial Horn Phased
Array. Sensors 2022, 22, 5329.
https://doi.org/10.3390/s22145329
Academic Editor: Changchuan Yin
Received: 21 June 2022
Accepted: 14 July 2022
Published: 16 July 2022
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Article
Microstrip-Fed 3D-Printed H-Sectorial Horn Phased Array
Ivan Zhou
1,
* , Lluís Pradell
1
, José Maria Villegas
2
, Neus Vidal
2
, Miquel Albert
1
, Lluís Jofre
1
and Jordi Romeu
1
1
School of Telecommunication Engineering, Universitat Politècnica de Catalunya, 08034 Barcelona, Spain;
lluis.pradell@upc.edu (L.P.); miquel.albert@estudiantat.upc.edu (M.A.); luis.jofre@upc.edu (L.J.);
jordi.romeu-robert@upc.edu (J.R.)
2
Department of Electronics and Biomedical Engineering, Universitat de Barcelona, 08028 Barcelona, Spain;
j.m.lopez_villegas@ub.edu (J.M.V.); nvidal@ub.edu (N.V.)
* Correspondence: ivan.zhou@upc.edu; Tel.: +34-934016826
Abstract:
A 3D-printed phased array consisting of four H-Sectorial horn antennas of 200 g weight
with an ultra-wideband rectangular-waveguide-to-microstrip-line transition operating over the whole
LMDS and K bands (24.25–29.5 GHz) is presented. The transition is based on exciting three overlapped
transversal patches that radiate into the waveguide. The transition provides very low insertion losses,
ranging from 0.30 dB to 0.67 dB over the whole band of operation (23.5–30.4 GHz). The measured
fractional bandwidth of the phased array including the transition was 20.8% (
24.75–30.3 GHz
). The
antenna was measured for six different scanning angles corresponding to six different progressive
phases
α
, ranging from 0
◦
to 140
◦
at the central frequency band of operation of 26.5 GHz. The
maximum gain was found in the broadside direction
α
= 0
◦
, with 15.2 dB and efficiency
η = 78.5%
,
while the minimum was found for α = 140
◦
, with 13.7 dB and η = 91.2%.
Keywords: printed antennas; 3D antennas; horns; low-loss antennas; 5G millimeter-wave antennas
1. Introduction
Fifth generation (5G) millimeter-wave (mmWave) communication is a promising
solution to the problem of the demand on network capacity, providing low latency and
high data speed. However, higher propagation losses will also be introduced, requiring
beamforming capabilities [1] for the transmitters in order to mitigate these effects [2].
The availability of chip beamformers [
3
] at these frequencies makes microstrip line
(ML)-based circuitry the optimum solution for the implementation of RF electronics. This
is not the best choice for antenna design, due to the propagation losses inside the substrate
of an ML. Investigations in [
4
,
5
] revealed that the ML is more suitable for feeding arrays of
a small or medium size, because the existence of the inevitable dielectric loss in substrates
limits the antenna gain. It is therefore necessary to have an alternative technology for
designing high-gain antennas that can easily be integrated into beamforming chips.
In this regard, horn antennas are proposed, where the gain can be increased by
enlarging the radiating aperture and the costs and weights can be reduced by using additive
manufacturing techniques such as 3D printing [
6
]. There are multiple printing methods,
such as selective laser sintering (SLS) [
7
], where a laser selectively sinters the particles of a
polymer powder, fusing them together and building a part layer by layer; fused deposition
modeling (FDM) [
8
], where molten plastic is extruded from a computer-controlled hot-end
and cooled to form a part; stereolithography (SLA) [
9
], where a light source is used to
selectively harden photo-activated resins; material jetting (MJ) [
10
], where the printheads
are used to deposit a liquid photoreactive material onto a build platform layer upon
layer; and direct metal laser sintering (DMLS) [
11
], similar to FDM but with a metallic
powder. In [
12
], a fully 3D-printed complex corporate feeding network with 256 horns
was successfully manufactured using DMLS, but the cost was high. Many cost-effective
Sensors 2022, 22, 5329. https://doi.org/10.3390/s22145329 https://www.mdpi.com/journal/sensors
