EMC/EMI Course Syllabus
Introduction To EMC
- Background terms and definitions
Commercial And Military Standards On EMC
- Brief description of the Purpose and intent of the standards, with focus on those requirements which are difficult to meet
Spectrum And Time Domain Signals
- Spectrum of communication data signals, clocks and switching mode power supplies.
- Engineering aspects of the parameters which often cause failures in EMC Compliance testing
Cables In EMC: As Radiators And As Radiation Receptors
- A cable as an elementary antenna and its extension to electrically long cables.
- Identification of the parameters determining the radiation intensity and controlling them
- The Model of a cable as a receptor of Electromagnetic Radiation,
- Identification of the parameters determining the amplitude of the reception and controlling
Switched Mode Power Supplies
- Sources of interference in switched mode power supplies-SMPS,
- Identification of the generators of interference and their control, filtering an SMPS to comply with the require-ments of conducted Emissions on the power leads.
Filtering Of Conducted Interference
- Principles of EMI Filtering,
- Structure and topology of common filters,
- Limitations of filtering components,
- Selection of a filter based on termination impedances and filtering requirements.
- Filtered pin connectors.
- The importance of the placement of the filter,
- Considerations when selecting or designing a filter
- The need for shielding,
- Materials used for shielding,
- Properties of metals conducive to shielding,
- Basic shielding theory,
- Engineering results as to the materials to be used,
- Shielding integrity faults due to penetrations and apertures and how to control them, engineering results as to bolt spacing.
- Cable shielding, gaskets, vents, viewing ports
- Sources of transients,
- Expression for transient immunity in the standards for lightning,
- Inductive load switching and ESD.
- Selection of TVS transient voltage suppressor components to comply with the standards
- Purpose of grounding,
- Impedance of conductors used for grounding,
- Single and multiple point grounding,
- High speed board grounding
- Bonding for electrical continuity,
- Electro-chemical properties of metals, corrosion effects, surface treatment to avoid corrosion,
- Bonding resistance requirements
EMC Aspects Of Electronic Circuit Design
- Selection of electronic component technology to minimize conducted and radiated Emissions.
- Board design for component placement, layer stack-up, separation of traces, area segregation in ground and power planes,
- Pin allocation in board to mother board connectors,
- On board filtering
Preparedness For EMC Lab Testing
- The requirements of the standards,
- The EMC Test Plan,
- Setting the modes of operation, setting the pass-fail criteria, separation between the equipment being tested and the associated controlling-operating equipment
Spectral Analysis and Case studies
- Signals in time and Frequency Domain
- Types of Spectrum Analyzers
- Basic Block Diagram of an Analog SA
- The SA as a Receiver
- Selectivity, AGC, LO Phase Noise
- Microwaves Spectrum Analyzer
- Frequency Resolution and RBW
- Limitations on the Sweep Rate
- RF Attenuator
- IF Amplification
- Shape Factor of the RBW Filter and Sweep Rate
- Noise Floor
- Video Signal Filtering (Post-Detection)
- Filtering by Averaging Screens
- SA Controls (Span, RBW, Att, VBW)
- Dynamic Range
- Detector Types and their Characteristics
- Sampling and the Sampling Theorem
- Spectrum of a Uniformly Sampled Signal
- Artifacts in Digitally Processed Spectrum Display
- Side-Lobes in Frequency Domain and Windowing
- RBW broadening by Windowing
- 0nd and 0rd Order Distortions and Spurii – Identification of Saturation in the SA
- Effect of LO Phase Noise
- Residual FM
- Time Domain Measurements – Zero Span
- Signal Power response in time
- Intermodulation Measurements
- Intermodulation with two-tones Stimulus
- Adjacent channel power (ACP)
- Adjacent channel leakage ratio (ACLR)
- Tracking Generator Configuration and Scalar Network Analyzer Measurements
- Demonstration of SA operation and Measurements
- Solver Choice
- Basic Meshing
- Workflow example
- Conducted emission
- Conducted Susceptibility
- Radiated emission
- Cables routing and the effect on the radiated emission.
- Radiation Hazard
- Lightning Strike simulation
- Antenna placement
- Antenna placement- Coverage analysis using Altair WinProp wave propagation tool.
Military EMI Control Standard For Equipment
- Mil Std 400G history, structure, basic requirements for lab facility, scan of the testing requirements, the purpose, rationale and limits. Tailoring of the standard limits
Commercial EMI Control Standards For Equipment
- FCC part 08 limits on conducted and radiated emissions.
- The difference between class A and Class B ITE,
- The meaning of a Quasi Peak limit.
- European community- CE EMI control standards,
- Emissions and susceptibility.
- The open area test site-OATS and its shielded enclosure replacement.Failure criteria.
- Scan of the immunity requirements per EN00222-4.