IEEE - Aerospace and Electronic Systems - March 2023 - 42

Spaceborne Multibeam Phased Array Antennas for Satellite Communications
Figure 25.
Hispasat 36W-1. (a) Satellite in orbit diagram. (b) Receiving
antenna structure. (c) Subarray model.
satellite was successfully launched on an Atlas-2AS
rocket on June 19, 2001. An MEO constellation of 10 satellites
is chosen for this system, taking into account the
feasibility and technical risks of the satellite itself, as well
as the quality of service provided to users. Two S-band
127-unit PAAs mounted on the satellite serve as receiving
and transmitting antennas, respectively. Therefore, the satellite
is able to form 163 transmit and receive service link
beams to cover the Earth using full DBF technology.
2) SatixFy Digital ESMA: The all-digital 256-element
electronically steerable multibeam array (ESMA) (see
Figure 28) [14], proposed by SatixFy, is the world's first
PAA for Ku-band satellite communications, capable of serving
as a building block for a larger array. The antenna is
made up of eight Primes and 64 Ku-band beats, and it can
form up to 32 beams at the same time. Prime is the first commercial
DBF ASIC chip to achieve real-time latency in satellite
communications. It digitizes the signal from each antenna
element using high-speed ADCs and digital-to-analog converters,
with data rates exceeding 2 Tbps. The chip can handle
32 signals at once and can be used with any size antenna. In
addition, beat, the SatixFy's first-generation RF frontend, is a
Ku-band RFIC that connects Prime's I/Q signals to Ku-band
antenna elements (RFFE). It combines a transmit driver, a
PA, a transmit up-converter, a receive LNA, a receive downconverter,
and antenna polarization control. A beat can support
four Ku-band antenna elements in half-duplex mode.
OBF TECHNOLOGY
Figure 26.
Eutelsat Quantum. (a) Satellite in orbit diagram. (b) Receiving
antenna structure. (c) Radiating element.
Spainsat. Furthermore, it employs analog beamforming
technology to generate eight independent reconfigurable
beams with a beamwidth of0.75. This antenna, when compared
to standard phased arrays, maximizes beam flexibility
ofPAAs via a software-defined approach.
DBF TECHNOLOGY
1) Intermediate Circular Orbit (ICO) (2000-2001):
ICO system (see Figure 27) [20] is based on the INMARSAT-P
system proposed by INMARSAT in 1990, with the
goal of providing handheld mobile communication services
to users worldwide. After the first ICO satellite was
destroyed by a launch failure in 2000, the second ICO
42
Figure 27.
ICO satellite.
IEEE A&E SYSTEMS MAGAZINE
MARCH 2023
The optical PAA employs the optical true time delay
(OTTD) line to avoid the limitation of the signal's
instantaneous bandwidth caused by the transit time and
aperture effect of the traditional PAA, thereby meeting
the wide-bandwidth requirements of the large-diameter
PAA. It will be a significant step forward in the development
of spaceborne antenna technology. At the moment,
countries all over the world have begun to actively investigate
its application in the field of space, and the spaceborne
application research is ready to enter the flight test
stage.
European Space Agency: In 2007, the Netherlands'
National Aerospace Laboratory proposed the use of
optical waveguide microloop delay technology for
IEEE - Aerospace and Electronic Systems - March 2023

Table of Contents for the Digital Edition of IEEE - Aerospace and Electronic Systems - March 2023
