Modulated scattering techniques calibration procedure for a 2D array

Garreau, Ph.; Klooster, C.G.M. van 't; Bolomey, Jean-Charles; Picard, Dominique

doi:10.1109/aps.1992.221742

Cited by 4 publications

(9 citation statements)

References 2 publications

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“…Typically a response calibration is performed to correct for any distortions [24]. The response calibration is performed by illuminating the retina with a known electric field.…”

Section: A Calibration and Electric Field Pattern Measurementsmentioning

confidence: 99%

“…This camera, which is primarily a 2-D coherent vector electric field mapping device, provides for adequate spatial sampling, reasonable aperture size, relatively large dynamic range, and video frame-rate image production. The camera collector consists of a 24 24 (576 elements) array of switchable slot antennas, spaced by , where is the free-space wavelength. Each element is loaded with a PIN diode facilitating fast switching for the purpose of real-time mapping of the electric field distribution at the aperture of the camera.…”

mentioning

confidence: 99%

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Portable Real-Time Microwave Camera at 24 GHz

Ghasr

Abou‐Khousa

Kharkovsky

et al. 2012

IEEE Trans. Antennas Propagat.

100

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This paper presents a microwave camera built upon a two-dimensional array of switchable slot antennas. The camera borrows from modulated scattering techniques to improve isolation among the array elements. The camera was designed to measure vector electric field distribution, be compact, portable, battery operated, possess high dynamic range, and be capable of producing real-time images at video frame-rate. This imaging system utilizes PIN diode-loaded resonant elliptical slot antennas as its array elements integrated in a simple and relatively low-loss waveguide network thus reducing the complexity, cost and size of the array. The sensitivity and dynamic range of this system is improved by utilizing a custom-designed heterodyne receiver and matched filter for demodulation. The performance of the multiplexing scheme, noise-floor and dynamic range of the receivers are presented as well. Sources of errors such as mutual-coupling and array response dispersion are also investigated. Finally, utilizing this imaging system for various applications such as 2-D electric field mapping, and nondestructive testing is demonstrated.

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“…Typically a response calibration is performed to correct for any distortions [24]. The response calibration is performed by illuminating the retina with a known electric field.…”

Section: A Calibration and Electric Field Pattern Measurementsmentioning

confidence: 99%

mentioning

confidence: 99%

Portable Real-Time Microwave Camera at 24 GHz

Ghasr

Abou‐Khousa

Kharkovsky

et al. 2012

IEEE Trans. Antennas Propagat.

100

View full text Add to dashboard Cite

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“…A sufficient condition for the absence of local minima in 4l is that 4l(A) does not present minima different from A = 0 along any arbitrary direction E' 1 . This is accomplished if only for A = 0, which happens if It is interesting to discuss under which conditions relation (12) can be satisfied. First note that while a and c are made up of only positive contributions, because of their very definitions as norms, b is made up of both positive and negative contributions, because the ranges of A i , A 2 and g belong to a set of complex functions, so that a"cancellation effect" occurs in its evaluation.…”

Section: Review Of the Geometrical Properties Of The Mappingmentioning

confidence: 99%

“…Another case where only incomplete information about the radiated field is available occurs when Modulated Scattering Techniques (MST) [6][7][8] are used [9][10][11][12] to perform near field measurements.…”

Section: Introductionmentioning

confidence: 99%

“…Since 1-D or 2-D arrays of electrically modulated scattering probes are employed, such a technique enables one to obtain a significant reduction in the acquisition time with respect to conventional techniques requiring mechanical positioning of a single probe and/or of the antenna under test [8,12]. For instance, in the case of 2D probe array, it is possible to scan a matrix of 32 x 32 measurement points, with a gain of the order of 100/1000 on the typical time obtained adopting standard mechanical scan.…”

Section: Introductionmentioning

confidence: 99%

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Antenna pattern determination by MST from square complex field data

Leone¹,

Pascazio

Pierri

1996

Journal of Electromagnetic Waves and Applications

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Near field techniques for antenna testing deal sometimes with incomplete data. In this paper we consider the Modulated Scattering Technique (MST), which, in the monostatic measurement configuration, probes directly the complex square of the near field. In this case, at each measurement point, the correct phase determination must be associated with the available signal in order to compute the radiation pattern. Such a non linear problem is formulated as the inversion of a quadratic operator connecting the unknown near field distribution over a plane to the available square field data. The solution is then defined as the global minimum of an appropriately defined fourth order functional. A second set of square field data, collected over a different planar surface, plays an important role in order to overcome the problem of the local minima occurrence in the minimization procedure. The similarity of the present problem with the so-called phase retrieval problem for the same scanning configuration is also emphasized. The numerical results for a planar geometry confirm the reliability of this approach when realistic data are used.

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