Determining Direction‐of‐Arrival Accuracy for Installed Antennas by Postprocessing of Far‐Field Data

Frid, Henrik; Malmström, Johan; Jonsson, B. L. G.

doi:10.1029/2019rs006975

Cited by 11 publications

(9 citation statements)

References 37 publications

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“…The possibility of using the generalized impedance density to predict where to place absorbers to reduce the mutual coupling between two wideband antennas integrated in the platform is investigated here. A 6×8 element body-of-revolution (BOR) array antenna [29], [30], depicted in Fig. 13(b), is used and referred to as Antenna 1.…”

Section: Integrated Antennasmentioning

confidence: 99%

Visualization and Reduction of Mutual Coupling Between Antennas Installed on a Platform

Lundgren

Malmström

Hannula

et al. 2022

IEEE Trans. Electromagn. Compat.

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Mutual coupling, or equivalently, the isolation between antennas, is a key parameter in antenna system design. In this article, the previously defined impedance density is generalized, and it is demonstrated how it can be used to obtain spatial information about the mutual coupling. The generalized impedance density is a real-valued scalar and it can be visualized as a threedimensional (3-D) density in space. It is shown that there is a strong connection between regions with a positive (negative) generalized impedance density and a decrease (increase) of the coupling when an absorber is placed in that region. This predictive ability is a useful feature, which is tested for three numerical cases. The results are robust to the shape of the platform, and it can be compared across frequencies. By placing absorbers based on the generalized impedance density, it is possible to reduce the required amount of absorbers needed to obtain a certain reduction in mutual coupling. The visualization results and predictions of absorber positions are compared with a Poynting vector based method. Placing absorbers based on the generalized impedance density had a larger impact on the mutual coupling, compared to the predictions with the Poynting vector based method in the investigated cases.

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Section: Integrated Antennasmentioning

confidence: 99%

Visualization and Reduction of Mutual Coupling Between Antennas Installed on a Platform

Lundgren

Malmström

Hannula

et al. 2022

IEEE Trans. Electromagn. Compat.

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“…The possibilities of using the weak-coupling density to predict where to place absorbers to reduce the mutual coupling between two wideband antennas integrated in a platform is here investigated. A 6x8 element body-of-revolution (BoR) array antenna [25], [26] with length L a = 50 mm, width w a = 43 mm, and height h a = 35 mm that is depicted in Fig. 11(b) is used and referred to as Antenna 1.…”

Section: Integrated Antennasmentioning

confidence: 99%

Visualization and Reduction of Mutual Coupling Between Antennas Installed on a Platform

Lundgren¹,

Malmström²,

Hannula³

et al. 2020

Preprint

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Mutual coupling, or equivalently, the isolation between antennas, is a key parameter in antenna system design. In this work, a new quantity is proposed to obtain spatial information about mutual coupling. The new quantity is named the weak-coupling density. This quantity is a real-valued scalar and can be visualized as a three-dimensional density in space. It is also shown that there is a strong correlation between regions with a positive (negative) weak-coupling density and decreasing (increasing) the coupling when placing an absorber in that region. This predictive ability is a useful feature, which is tested here for three numerical cases. The results are robust to the shape of the platform, and it persists over neighboring frequencies. By placing absorbers based on the weak-coupling density, it is possible to reduce the required amount of absorbers to obtain a certain mutual coupling reduction. The visualization results and predictions of absorber positions are compared with a Poynting vector based method. Placing absorbers based on the weak-coupling density had a larger impact on the mutual coupling, compared to the predictions with the Poynting vector based method in the investigated cases.

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“…In this paper, we will first focus on a four-quadrant monopulse array with common excitation weights used for DoA estimation, as described in e.g. [2]- [4]. While EW systems have a significantly larger bandwidth than radar or communication systems, our method works for arrays with any bandwidth.…”

Section: Introductionmentioning

confidence: 99%

Convex Optimization of Wideband Monopulse Arrays

Frid,

Hultin,

Jonsson

2024

IEEE Trans. Antennas Propagat.

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A convex optimization program is presented for wideband arrays. Constraints are imposed on the frequency variation of excitation coefficients to ensure that the optimal solution can be realized in a wideband active electronically scanned array (AESA). AESA implementation with true time delays (TTDs) and phase shifters are handled separately. We also discuss the general case of combining TTDs and phase shifters. Contrary to single-frequency optimization, the wideband optimization method presented here ensures that the computed excitation is optimal over a specified bandwidth. It is shown that there is a trade-off between instantaneous bandwidth and sidelobe level. The proposed method works for both narrow and wideband arrays, as illustrated with examples. In addition to regular arrays, the method is also applicable to monopulse arrays. The optimization program is implemented in terms of embedded element patterns to account and compensate for mutual coupling, radome and platform effects.

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Determining Direction‐of‐Arrival Accuracy for Installed Antennas by Postprocessing of Far‐Field Data

Cited by 11 publications

References 37 publications

Visualization and Reduction of Mutual Coupling Between Antennas Installed on a Platform

Visualization and Reduction of Mutual Coupling Between Antennas Installed on a Platform

Visualization and Reduction of Mutual Coupling Between Antennas Installed on a Platform

Convex Optimization of Wideband Monopulse Arrays

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