For recognition, the front or trailing edge of projection of binary image on horizontal axis basically shows linear shape, so least square theory is applied in tilt correction.

At high speeds, logic signals often appear hairy, jagged and distorted because of fast signal rise and fall time. We must avoid these phenomena in the high-speed digital circuit system.

Several different time domain waves with different ascending time and degressive time are fed into axial-mode helical antennas, and different radiated fields are gained.