Calculation of crosstalks in multiple-conductor cables
The rigorous method of calculations of characteristics of two-wire lines (twisted pairs) inside the metal armor and of a mutual coupling between lines is considered. It is shown that the mutual coupling between lines in multiple-conductor cables results in appearance of electromagnetic interferences (crosstalks) in communication channels. The voltages values (interferences) across the impedances placed at the beginning and the end of the adjacent line at the given power in the main line are determined.
A Prediction Method of Cable Crosstalk in Electronic Systems with Ensemble Learning
Crosstalk between cables can seriously impede the performance of electronic systems. Cable layouts are becoming increasingly complex, and crosstalk is influenced by many factors, so it is difficult for existing crosstalk prediction methods to accurately establish direct relationships between cable near-end crosstalk and its numerous influencing factors. In order to identify the electromagnetic compatibility (EMC) problems of electronic systems in the early stage of cable layout design to guide the optimization of cable layout, the stacking-LSRM multi-stage ensemble learning method was proposed. Using this method, a cable crosstalk prediction model with high prediction accuracy and good robustness can be quickly established programmatically. Two examples were used to verify the effectiveness of the proposed method. In each example, the overall performance of the obtained optimal ensemble learning prediction model was quite good, and the effectiveness of the proposed method was verified by comparison with the prediction models established by existing methods.
rPET detectors design and data processing
Small animal PET systems based on rotating planar detectors posses some interesting advantages for high sensitivity, high resolution imaging. We have designed the rPET detectors based on MLS crystals assembled on a 30times30 matrix optically coupled to a flat-panel PS-PMT. Weighted position readout circuits pre-process the 64 signals from the 8times8 anodes matrix, which are digitized using a charge-integrating converter. The amplification electronics, including the trigger output for coincidence detection, and the high voltage supply are integrated in a three PCBs stack that forms the base attached to the back of the PMT. The whole assembly is enclosed in a light tight, lead (Pb) shielded aluminum box. The detectors are mounted on a rotating gantry with more than 180 degrees rotation span. The digitized events are screened and histogramed, and a modified center of gravity algorithm removes from the position calculation those signals with poor signal to noise ratio. Apparent mean crystal size on the 511 keV field-flood images is 0.6 mm, mean peak-to-valley ratio is better than 8, and intrinsic resolution is 1.5 mm at the central row, with the energy window wide open. Sensitivity (CPS) for a pair of these detectors set in coincidence at 160 mm distance is 1%