Signal Spectrum Reduction by Phase-Difference Transmission
Original Publication Date: 1986-Feb-01
Included in the Prior Art Database: 2005-Mar-08
This article describes a solution to a problem concerned with the signal transmission of high frequency through a long path, which frequently causes a radiated Electromagnetic Interference (EMI) problem or several signal distortion problems, etc. Today, it is quite important for CRT display terminals, in particular for the low-end, to comply with the regulation of radiated EMI, such as US FCC-EMI, German VDE-RFI, etc. The radiated E-field is sourced from base-clock and video signal, especially video signal due to running through a long path from the logic portion to the CRT. It is also known that E-field radiation is related to the spectrums contained in the video signal. Fig. 1 shows the principle of the new video interface circuit.