IEEE - Aerospace and Electronic Systems - February 2022 - 34

Feature Article:
DOI. No. 10.1109/MAES.2021.3121654
Multibeam Antennas With Reflector for High
Throughput Satellite Applications
Liujie Lei , Jixiang Wan, and Qi Gong, China Academy of Space Technology,
Xi'an 710000, China
INTRODUCTION
The coverage of conventional telecommunication satellites
usually included one country or one continent with
single wide beam, which indicates that the contour of
antenna pattern should fit the shape of the coverage. This
is called the single shaped wide beam method, which is
commonly used in traditional satellites with wide beamwidth.
It can reduce the waste of power through cutting
off extra areas outside the coverage [1]. The irregular
circles shown in Figure 1 are contours of the single shaped
wide beam method covering China continent. This method
uses one beam to illuminate such a wide coverage so that
the beamwidth is large leading to deteriorated gain and
the allocated frequency spectrum can be used only once.
Thus, it is hard to satisfy telecommunication capacity and
bandwidth needs in China this way. Hence, the method is
not able to fulfill the needs of high throughput and high
efficiency in current satellites communication.
To solve these problems of the single shaped wide
beam method, multibeam antenna technology of satellite
is proposed. The coverage of multibeam antenna method
illuminating China continent is shown in Figure 1. Multiple
narrow beams will reduce extra areas outside the coverage
more precisely. Hence, the multibeam antenna
method can save power with higher efficiency. And in
recent two decades, telecommunication satellites with
multibeam antennas have been developing toward high
throughput satellite (HTS) with high capacity, high efficiency,
and high capacity density. Due to limited spectrum
distributed to satellites by ITU, multiple spot beams and
Authors' current addresses: L. Lei, J. Wan, and
Q. Gong, China Academy of Space Technology,
Xi'an 710000, China (e-mail: liujie.lei@foxmail.com;
13992841372@163.com; gongqi22@126.com).
Manuscript received April 15, 2021, revised July 24,
2021; accepted October 8, 2021, and ready for
publication October 18, 2021.
Review handled byMauro De Sanctis.
0885-8985/21/$26.00 ß 2021 IEEE
34
frequency or polarization reuse scheme are the core
technologies for HTS to provide dozens of times more
capacity than conventional telecommunication satellites.
Narrow beamwidth and high gain ofHTS make it possible
to save power and reduce cost with miniaturized ground
equipment. The demands of high equivalent isotropically
radiated power (EIRP), broadband, extraordinary gain-tonoise
temperature (G/T), and copolar isolation (C/I) of
HTS stimulate more advanced multibeam antenna technology
to satisfy double needs of ground user terminals
and high-speed broadband multimedia communication.
Besides, the cost per b/s of HTS is much lower than that
of traditional satellites. In the near future, HTS will have
enormous significance over the space industry, telecommunication
industry, and global broadband access [2].
In this article, principles and classifications of multibeam
antenna with reflector are first illustrated. And then
some HTS missions using multibeam antenna with reflector
launched successfully over the past two decades are
presented. We find that the system capacity of HTS proceeds
from single digit to hundreds of Gb/s. The end of
this article introduces some latest technologies and development
trends ofHTS.
PRINCIPLES OF MULTIBEAM ANTENNA WITH
REFLECTOR
Multibeam antennas with reflector are complex due to the
amount of reflectors and feeds layout. Only one reflector
is not enough when large amount of beams are located
closely together. Usually multiple reflectors are installed
on satellite decks. According to the number of feeds per
beam, multibeam antenna with reflector can be divided
into the following two categories: single feed per beam
(SFPB) and multiple feeds per beam (MFPB) antennas.
And the principles of SFPB with multiple reflectors and
MFPB antennas are specified in this part. The multibeam
antennas mostly used are parabolic reflector antennas fed
by horns. There are many advantages ofparabolic reflector
antennas. Electromagnetic waves will transfer into plane
IEEE A&E SYSTEMS MAGAZINE
FEBRUARY 2022
https://www.orcid.org/0000-0002-1296-7070
IEEE - Aerospace and Electronic Systems - February 2022

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