A Characteristics And Application Research On The High-speed Digital Clock Circuit Electromagnetic Radiation

EMC is a experiment science which integrated the electromagnetic field theory,antenna, microwave, low-frequency circuits, structures, materials, digital circuit,channel, mathematics, physics, instrumentation, measurement and many otherdisciplines as one. With the increase of the frequency equipment in various trades,electromagnetic spectrum is one of the most important resources. In order to ensure thatmany electronic devices will not interfere with each other, to achieve the goal ofcompatible work, unintentional emission devices must be controlled. The clock circuitis one of the many electromagnetic interference sources, it has been used in almost all ofthe electronic devices. More than a half of the electromagnetic compatibility issuesAscribes the clock circuit. A wide spectrum, and the concentrated energy is thecharacteristics of the clock oscillator. This thesis seek a most simple, most effectivesolution for the clock circuit interference problems encountered in engineering.Focus on the clock interference issues, this thesis has a in-depth analysis of theclock generator radiation mechanism, pathways, and come up with a set of practicalelectromagnetic reinforcement design methods based on them. The application of thisreinforcement design method succeeded in solving an airborne radio noise problem.Mainly as follows:1. The mechanism research of high-speed digital clock circuit electromagneticradiation.To establish the equivalent circuit of the high-speed digital clock circuits; In use ofthe Maxwell’s electromagnetic field theory, antenna theory and the Fourier transform, toanalysis the electromagnetic radiation mechanism of high-speed digital clock circuits inthe frequency domain; to provide the method of modeling, of transforming between thetime domain and the frequency domain, and of the electromagnetic radiation calculatingin frequency domain; The radiation level of high-speed digital clock circuits in thefrequency domain is to give quantitatively as well.2. The electromagnetic reinforcement method research of high-speed digital clockcircuit. According to the electric field radiation theory of clock circuit, to research mostlikely electromagnetic radiation way of high-speed digital clock; to analysis methods toreduce the electromagnetic radiation; Binding electromagnetic radiation level of theclock circuit and the maximum acceptable value of electromagnetic compatibilitystandard specification, to research and design an appropriate reinforcement measures(such as filtering, shielding, or both); To give the most simple and effective parameterdesign method of the reinforcement circuit.3. The application case research of high-speed digital clock circuit electromagneticradiation reinforcement method.A engineering case apply to an aviation control and management equipment areprovided. By means of theoretical analysis and comparison experiments, to identify thespecific interference sources, pathways in the control and management equipment;Based on the practical application in engineering of the device, to research a realizablereinforcement measures and methods.