5.1. Energy considerations5.2. Equivalent circuit5.3. Determination of WE, WM, and B for a rectangular patch5.4. Modeling using a tank circuit5.5. Quality factor of an antenna5.6. Calculation of radiation quality factor5.7. Calculation of efficiency5.7.1. Losses in conductive walls5.7.2. Losses in the dielectric5.7.3. Radiated power5.8. Influence of surface waves on bandwidth and efficiency