Altair Case Studies Characterizing the Murchison Widefield Array Beam Pattern with FEKO

	Characterizing the Murchison Widefield Array Beam Pattern with FEKO Altair

Characterizing the Murchison Widefield Array Beam Pattern with FEKO

Altair

Technology Category	Analytics & Modeling - Digital Twin / Simulation Networks & Connectivity - RFID
Applicable Industries	Aerospace Chemicals
Applicable Functions	Procurement
Use Cases	Traffic Monitoring Virtual Reality
Services	Testing & Certification
Challenge	The Murchison Widefield Array (MWA) radio telescope, a precursor to the Square Kilometer Array (SKA), was facing a challenge in characterizing its beam pattern. The beam pattern of the array could be determined using measurement, but this method was time-consuming and required specialized equipment. Therefore, a simulation-based approach was deemed the most practical. The beam pattern is a function of each of the 16 array elements as well as the operational frequency of the system. To model the pattern, each of the array elements had to be excited independently, and at different frequencies within the operation band. The full array beam pattern could then be modeled at an arbitrary steering direction. Previously, the simulation of the beam pattern was conducted using analytical models, but a more rigorous approach was needed where the full array geometry was simulated. Read More
About Customer	The customer in this case study is the Murchison Widefield Array (MWA) radio telescope, which is a precursor to the Square Kilometer Array (SKA). The MWA is located in the Murchison Radio-astronomy Observatory in Western Australia. It comprises of 128 tiles, each an array consisting of 16 uniformly distributed antenna elements in a 4×4 configuration, 1.1 m apart. The work presented in this case study focuses on an electronically steered phased array, where steering is achieved by introducing phase delays to each element in the array. Phased array antennas have direction dependent primary beams. In order to correctly calibrate and image the data collected by the radio telescope, it is imperative that the beam pattern is known accurately. Read More
Solution	FEKO, Altair’s electromagnetic simulation tool, was used to overcome the challenges faced in this case study. Due to the large number of different configurations that were to be analyzed, FEKO’s automation played a key role in enabling the different configurations to be set up automatically, saving a significant amount of time. FEKO’s spherical mode far-field representation was also required to reconstruct the array beam pattern with adjustable resolution in azimuth and zenith angle. FEKO’s Method of Moments (MoM) solver was used, which is known to be both accurate and highly efficient to solve problems with these attributes. The array was modeled over a 5x5m solid ground plane. Each LNA was represented by a lumped RLC circuit, which is attached to the feed port of each array element. The ground under the array was modeled using FEKO’s planar multilayer substrate model, with typical permittivity and conductivity for soil with 2% moisture content. Read More Log in to view content
Contents

Technology Category

Analytics & Modeling - Digital Twin / Simulation

Networks & Connectivity - RFID

Applicable Industries

Aerospace

Chemicals

Applicable Functions

Procurement

Use Cases

Traffic Monitoring

Virtual Reality

Services

Testing & Certification

Challenge

The Murchison Widefield Array (MWA) radio telescope, a precursor to the Square Kilometer Array (SKA), was facing a challenge in characterizing its beam pattern. The beam pattern of the array could be determined using measurement, but this method was time-consuming and required specialized equipment. Therefore, a simulation-based approach was deemed the most practical. The beam pattern is a function of each of the 16 array elements as well as the operational frequency of the system. To model the pattern, each of the array elements had to be excited independently, and at different frequencies within the operation band. The full array beam pattern could then be modeled at an arbitrary steering direction. Previously, the simulation of the beam pattern was conducted using analytical models, but a more rigorous approach was needed where the full array geometry was simulated.

About Customer

The customer in this case study is the Murchison Widefield Array (MWA) radio telescope, which is a precursor to the Square Kilometer Array (SKA). The MWA is located in the Murchison Radio-astronomy Observatory in Western Australia. It comprises of 128 tiles, each an array consisting of 16 uniformly distributed antenna elements in a 4×4 configuration, 1.1 m apart. The work presented in this case study focuses on an electronically steered phased array, where steering is achieved by introducing phase delays to each element in the array. Phased array antennas have direction dependent primary beams. In order to correctly calibrate and image the data collected by the radio telescope, it is imperative that the beam pattern is known accurately.

Solution

FEKO, Altair’s electromagnetic simulation tool, was used to overcome the challenges faced in this case study. Due to the large number of different configurations that were to be analyzed, FEKO’s automation played a key role in enabling the different configurations to be set up automatically, saving a significant amount of time. FEKO’s spherical mode far-field representation was also required to reconstruct the array beam pattern with adjustable resolution in azimuth and zenith angle. FEKO’s Method of Moments (MoM) solver was used, which is known to be both accurate and highly efficient to solve problems with these attributes. The array was modeled over a 5x5m solid ground plane. Each LNA was represented by a lumped RLC circuit, which is attached to the feed port of each array element. The ground under the array was modeled using FEKO’s planar multilayer substrate model, with typical permittivity and conductivity for soil with 2% moisture content.

Impact #1	The use of FEKO in this case study resulted in a more accurate characterization of the MWA's beam pattern compared to previous analytical models. The simulation-based approach allowed for the modeling of the full array geometry, taking into account each of the 16 array elements and the operational frequency of the system. The automation capabilities of FEKO saved a significant amount of time in setting up the different configurations for analysis. The Q-leakage test, which measures the fractional linear polarization, was used to test the validity of the model presented in this study. The results showed vast improvements in accuracy compared to the analytical approach, demonstrating the effectiveness of the approach used in this case study. This work lays the foundation for the EM simulations that will be used for the SKA low telescope.

Impact #1

The use of FEKO in this case study resulted in a more accurate characterization of the MWA's beam pattern compared to previous analytical models. The simulation-based approach allowed for the modeling of the full array geometry, taking into account each of the 16 array elements and the operational frequency of the system. The automation capabilities of FEKO saved a significant amount of time in setting up the different configurations for analysis. The Q-leakage test, which measures the fractional linear polarization, was used to test the validity of the model presented in this study. The results showed vast improvements in accuracy compared to the analytical approach, demonstrating the effectiveness of the approach used in this case study. This work lays the foundation for the EM simulations that will be used for the SKA low telescope.

Benefit #1	Huge time savings from automation of configurations
Benefit #2	Efficient solvers to represent geometry, LNA impedance and soil
Benefit #3	218 frequency points, 16 array elements, 2 polarizations, nearly 7000 configurations analyzed

Benefit #1

Huge time savings from automation of configurations

Benefit #2

Efficient solvers to represent geometry, LNA impedance and soil

Benefit #3

218 frequency points, 16 array elements, 2 polarizations, nearly 7000 configurations analyzed

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Overview

Characterizing the Murchison Widefield Array Beam Pattern with FEKO

Operational Impact

Quantitative Benefit