Antennas and Propagation TZ2C100005

LECTURES

1. Introduction. Applications and classification of antennas. Antenna structural diagram. Sources of radiation. The principle of similarity. The principle of reciprocity. Field zones in the surrounding of the radiation source. Electromagnetic plane wave. Wave polarization.

2. Basic parameters of antennas. Radiation pattern. Directivity, efficiency, gain. Effective length and effective area. Radiation resistance, input impedance, loss resistance. Electromagnetic field distribution around the Hertz dipole. The Hertz dipole parameters. Elementary magnetic dipole.

3. Radiation patterns of dipoles. Radiation resistance, directivity and effective length of the dipole. Short vibrator dipole. Input impedance of balanced vibrator.

4. The method of images. Linear antennas above the ground. Horizontal and vertical dipoles above the ground. Vertical monopole. GP antennas (Ground Plane). Connection of dipoles to balanced transmission lines and coaxial lines. Impedance matching. Reduction factor of half-wave dipole length. Folded dipole. Operating frequency. Baluns.

5. Antenna arrays. Field superposition, group characteristics (multipliers). Radiation of linear antenna group. Rectangular array. Resonant passive elements - reflectors and directors. Yagi-Uda antennas.

6. Aperture antennas. Radiation patterns of uniformly illuminated rectangular and circular apertures. Impact of the amplitude and phase changes in the aperture to the radiation pattern. Horn antennas: sectoral, pyramidal, conical. Optimal tubes. Impedance matching.

7. Parabolic antennas. Design of geometric dimensions of the parabolic antenna. Offset parabolic antennas. Radiators and polarizers. Dual reflector antennas.

8. Traveling-wave antennas - V-type and rhombic antennas. The idea of frequency-independent antennas. Log-periodic antenna. Log-periodic dipole antenna. Lens antennas. Planar antennas: microstrips and slots. Other antenna designs. Development trends.

9. Propagation of radio waves in the atmosphere. The atmosphere layers. Critical and limiting frequencies of ionospheric layers. The traditional classification of radio spectrum. Classification of ways of radio wave propagation. Austin formula for propagation of long waves. Propagation of medium waves, coverage areas, interferences of surface waves and ionospheric waves. Luxembourg effect. Short-wave propagation. Dead zones. The short-wave fading effects, Doppler effect, echo. Propagation of ultrashort waves and microwaves.

10. Safety rules in the electromagnetic field. Mechanisms and biological effects of electromagnetic fields interaction with the human body. Basic laws on occupational and environmental protection from the strong electromagnetic fields.

LABS

Acquainting students with techniques of measurement of antenna basic parameters, selected antenna designs used in consumer equipment, including Wi-Fi networks. Electronic measurement apparatus and automation examples.