ELECTRICAL PROPERTIES OF DIELECTRICS - Advanced Signal Integrity for High-Speed Digital Design - page 247

ELECTRICAL PROPERTIES
OF DIELECTRICS

6.1 Polarization of dielectrics 250

6.1.1 Electronic polarization 250

6.1.2 Orientational (dipole) polarization 253

6.1.3 Ionic (molecular) polarization 253

6.1.4 Relative permittivity 254

6.2 Classification of dielectric materials 256

6.3 Frequency-dependent dielectric behavior 256

6.3.1 Dc dielectric losses 257

6.3.2 Frequency-dependent dielectric model: single pole 257

6.3.3 Anomalous dispersion 261

6.3.4 Frequency-dependent dielectric model: multipole 262

6.3.5 Infinite-pole model 266

6.4 Properties of a physical dielectric model 269

6.4.1 Relationship between ε and ε

269

6.4.2 Mathematical limits 271

6.5 Fiber-weave effect 274

6.5.1 Physical structure of an FR4 dielectric and dielectric constant
variation 275

6.5.2 Mitigation 276

6.5.3 Modeling the fiber-weave effect 277

6.6 Environmental variation in dielectric behavior 279

6.6.1 Environmental effects on transmission-line performance 281

6.6.2 Mitigation 283

6.6.3 Modeling the effect of relative humidity on an FR4 dielectric 284

6.7 Transmission-line parameters for lossy dielectrics and realistic conductors 285

6.7.1 Equivalent circuit, impedance, and propagation constant 285

6.7.2 Telegrapher's equations for realistic conductors and lossy dielectrics 291

References 292

Problems 292