4 results about "Field intensity" patented technology

The invention relates to a short wave communication reliability evaluation method based on multi-system detection data. The method comprises the steps of: calculating reflection point positions of a short wave communication link and all detection links, and selecting detection link data close to the reflection point position of an ionized layer of the short wave communication link; according to the determined reflection point positions of ionized layers of the detection links and the determined detection link data, forecasting an ionized layer parameter of reflection points of the ionized layers of the detection links; according to the determined reflection point positions of the ionized layers of the short wave communication link and the detection links and the forecasted ionized layer parameter of the reflection points of the ionized layers of the detection links, reconstructing an ionized layer parameter of the reflection point of the ionized layer of the short wave communication link; forecasting the highest available frequency of the short wave communication link by using a short wave propagation forecasting method according to the obtained ionized layer parameter; and calculating the received field intensity when the short wave communication link adopts the highest available frequency for communication according to the obtained highest available frequency, and analyzing the reliability of the short wave communication link.

Methods and apparatuses for 3D tomographic imaging of objects such as soft-tissues in humans are disclosed. They are similar to the Magnetic Resonance Imaging (MRI) methods and apparatuses but they are based on the new Field Paradigm founded on the principle that the field intensity distribution in a 3D volume space uniquely determines the 3D density distribution of the field emission source and vice versa. The object to be imaged is first magnetized by a polarizing magnetic field pulse. The magnetization of the object is specified by a 3D spatial Magnetic Density Image (MDI) that needs to be determined. The magnetic field due to the magnetized object is measured in a 3D volume space that extends in all directions and in particular substantially along the radial direction from the center of the object being imaged. Further, magnetic field intensity may be measured along multiple directions at each point. This measured data captures all the available information and facilitates fast and accurate 3D image reconstruction. This is unlike prior art where measurements are made only on a surface at a nearly constant radial distance from the center of the target object. Therefore useful and available data is ignored and not measured in prior art. Consequently, prior art does not provide a fast and accurate solution to 3D imaging. The methods and apparatuses of the present invention are combined with frequency and phase encoding techniques of MRI in prior art to achieve different trade-offs.

The invention discloses an adaptive threshold adjusting method for a non-contact intelligent card demodulation system. An additionally-arranged adaptive threshold adjusting circuit in a non-contact IC card is utilized for accomplishment. The adaptive threshold adjusting circuit determines whether a threshold is appropriate according to the number of zeros in a zero number counter. After stabilization of a power-on simulation front end circuit, adjustment is carried out from a greatest threshold downwards, the great number of the zeros means that the threshold is too great, burr generation occurs, a fixed threshold step length is subtracted from a present threshold, after accomplishment of threshold switching of the simulation circuit, next determination is carried out continuously, till the number of the zeros reaches a prescribed range, the threshold reaches an optimum one, or demodulation for a smallest threshold is carried out. According to the adaptive threshold adjusting method, in a field intensity range of 1.5A/m-7.5A/m, for multiple antenna waveforms prescribed in an ISO/IEC14443TypeA protocol, a comparator threshold can be automatically selected, and demodulation data with pause width close to 3mus is outputted.