Improved sensitivity of a low noise aperture array tile for the SKA

Woestenburg, E. E. M.; Witvers, R.H.; Ruiter, M.; Benthem, P.

doi:10.1109/iceaa.2014.6903844

Cited by 6 publications

(10 citation statements)

References 3 publications

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“…For this case, ζ m = (Γ s,m S 11 ) −1 and Γ ef f s,m = S −1 11 . The reason that Γ ef f s,m ≈ S −1 11 can be explained with the help of Fig.…”

Section: Discussion On κ Mmentioning

confidence: 98%

“…When κ 1 is very large, reflection experienced by c 1 off Γ s,1 contributes very little to the output noise relative to the contribution through the coupled path. Therefore, Γ s,1 appears negligible, and c 1 is effectively referred to the LNA input (node b 1 ) for embedded-LNA noise temperature analysis with S −1 11 , i.e., it appears as if c 1 was reflected off signal source with a reflection coefficient of S −1 11 .…”

Section: Discussion On κ Mmentioning

confidence: 99%

“…It should also be noted that unlike the single-element case, the effective noise temperature of an embedded LNA may not be limited to T min . In (11), the term ξ m may be made less than 1 and even negative, thus causing the T ef f m to be lower than T min . Nevertheless, T ef f m is always greater than 0 even when ξ m < 0 regardless of beamformer coefficients.…”

Section: Discussion On the Embedded-lna Noisementioning

confidence: 99%

“…In (11), T 0 = 290 K is the reference temperature, T min is the minimum noise temperature of an LNA, Γ opt is the optimum reflection coefficient for minimum noise, N is the Lange invariant noise parameter 3 [26], and…”

Section: ) Input-referred Effective Available Noise Power Andmentioning

confidence: 99%

“…The verification of the equations derived so far, and in particular (11), was carried out by comparing their results against that obtained with an Agilent's Advanced Design System (ADS) simulation of an array of three antennas terminated with three identical LNAs followed by a beamformer. The antenna array was simulated with an equation-based coupler that allows users to specify its reflection coefficients and coupling coefficients.…”

Section: Verification Of the Embedded-lna Noise Modelmentioning

confidence: 99%

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Low-Noise Amplifier Design Considerations For Use in Antenna Arrays

Belostotski

Veidt

Warnick

et al. 2015

IEEE Trans. Antennas Propagat.

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This work analyzes the implications of noise coupling in arrays of antennas on the design of low-noise amplifiers (LNAs). To select LNA design parameters in a manner familiar to LNA designers, the effective noise temperatures T ef f of LNAs are presented. The effect of beamformer coefficients and antenna coupling on T ef f is analyzed in a manner similar to a stand-alone LNA analysis. This leads to the proposed LNA design strategy of selecting LNA Γopt near the reflection coefficient of antenna ports and selecting the largest practical |S11| with a proper phase. This strategy is based on the assumption that the antenna array may be used for various beamforming and nonbeamforming applications, unknown at the time of the design. Numerical simulations of a 38-and 41-element antenna arrays show that a global search of LNA S11 and Γopt, which result in the minimum average beamequivalent receiver noise temperature Trec, finds nearly identical results to the proposed LNA design strategy. For a 41-element array with high antenna coupling at low frequencies, the proposed method shows as much as 80% improvement in the Trec over conventional LNA design strategies that do not account for the intended use of the amplifier in an array.

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“…For this case, ζ m = (Γ s,m S 11 ) −1 and Γ ef f s,m = S −1 11 . The reason that Γ ef f s,m ≈ S −1 11 can be explained with the help of Fig.…”

Section: Discussion On κ Mmentioning

confidence: 98%

Section: Discussion On κ Mmentioning

confidence: 99%

Section: Discussion On the Embedded-lna Noisementioning

confidence: 99%

Section: ) Input-referred Effective Available Noise Power Andmentioning

confidence: 99%

Section: Verification Of the Embedded-lna Noise Modelmentioning

confidence: 99%

See 3 more Smart Citations

Low-Noise Amplifier Design Considerations For Use in Antenna Arrays

Belostotski

Veidt

Warnick

et al. 2015

IEEE Trans. Antennas Propagat.

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On the front-end design of mid-frequency aperture array for square kilometre array

et al. 2018

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Complementary to the conventional dish radio telescopes, aperture arrays provide a technically attractive approach to achieve a large field of view and flexibility in observational parameters e.g. Sky area vs. bandwidth. Designs of both aperture array elements and overall geometry for the SKA Mid Frequency Aperture Array are presented here, together with resulting trade-offs. The paper reports the latest developments of global efforts on the front-end design of Mid-Frequency Aperture Array, not attempting to make technology selections, as the priority of sciences and the time for implementing Mid-Frequency Aperture Array is yet to be fully confirmed. Different ongoing front-end solutions are introduced, particularly crossed ring antenna array with a planar structure is explored in more detail as it is less known in the community. Key performances of the candidate front-end technologies are addressed by examining the prototypes. The objective of the collaborative study is to increase technology readiness for implementation of Mid-Frequency Aperture Array in the future.

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