34Mobile_antennaBasic Antenna Principles for Mobile Communications Dipl. Ing. Peter Scholz KATHREIN-Werke KG Anton-Kathrein-Strae 1 83004 Rosenheim 1. 2. 3. 3.1 3.2 3.3 3.4 3.5 3.6 3.7 4. 4.1 4.1.1 4.1.2 4.1.3 4.2 4.2.1 4.2.2 4.2.3 4.2.4 5. 5.1 5.1.1 5.1.1.1 5.1.1.2 5.1.2 5.1.2.1 5.1.2.2 5.2 Introduction Theory Definitions Polarization Radiation Pattern Half-Power-Beam-Width Gain Impedance VSWR/Return Loss Mechanical features Base Station Antennas Omnidirectional Antennas Groundplane and λ/4-Skirt Antennas Side-mounted Omnidirectional Antennas Omnidirectional Gain Antennas Directional Antennas Gain Achieved via Horizontal Beaming End-fire Array Broadside Array Antenna Systems Particular Techniques used in GSM and DCS 1800 Diversity Space Diversity Omni-Base Station Sectored Base Station Polarization Di……