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The proposed MW treatment can be used by the food industry to obtain an excellent homogeneous heating of a green smoothie product retaining high levels of bioactive compounds during subsequent retail/domestic storage up to 1 month at 5 °C. © 2017 Society of Chemical Industry.

Abstract-In this study, a novel ten-port waveguide microwave sensor is designed, implemented, calibrated and tested in order to obtain the reflection coefficient magnitude and phase. This reflectometer is based on the well known six-port structure but the number of detectors has been increased to eight in order to improve the sampling procedure of the standing wave present within the waveguide. In addition, a learning method based on neural networks' usage has been implemented for autonomous calibration from the data collected by a vector network analyzer. An automated procedure consisting of a moving sample within a multimode cavity has enabled different reflection coefficients to be obtained. Neural networks have been employed in order to learn the relationship between the actual reflection parameter and the acquired signals from eight power detectors. This novel device has been calibrated with a neural architecture based on radial basis functions and the error of device measurements has been analyzed. This new design and the incorporated neural network calibration allow one to avoid problems caused by fault or nonlinearity of the detectors, and to get robustness, flexibility and adaptability characteristics for the presented device.

8510C Network Analyser. Figures 3 and 4 show the measured radiation patterns in the d-a-b and d-b-a orientations of the DR.The patterns of all the orientations are reasonably broad in both E and H planes. The cross-polarization is ϳ 20 dB, indicating the usefulness of the proposed antenna configuration for mobile communication. It is observed that the gain of the proposed antenna configuration is almost the same as that of a standard circular patch antenna with Ϯ 0.5-dB variation. CONCLUSIONExperiments were conducted on a high-permittivity rectangular DR excited by a 50⍀ microstrip line. It was observed that different resonant modes are excited at different locations of the DR along the feed line. Broad radiation patterns were obtained in almost all orientations, with the main lobe of the radiation pattern remaining normal to the ground plane of the structure with variations in orientation and frequency.

Abstract-In this paper, a novel load-matching procedure for microwave-heating applicators is presented and tested. In order to accomplish the optimization procedure, an optimization method based on the use of the Lebenverg-Marquardt technique has been specifically developed and tested on two different microwave ovens. The proposed procedure allows an efficient optimization of three-dimensional microwave applicators by means of the dielectric sample relocation as a function of its complex permittivity, size, and operating frequency. Experimental measurements of the reflection coefficient are presented and analyzed over several samples and multimode cavities. Results indicate that high power efficiencies can be obtained provided that operating frequency is not just below TM-mode cutoff frequencies for the transverse dimensions of the oven.