Basics of RF and Antenna Engineering, 5 cr

Core content:

The role of transmission lines (TL) in RF circuits as inherent impedance transformers (PCB traces) and TL circuit elements with specifically designed functions (e.g., replacing capacitors and inductors, quarter-wave transformer). Concepts related TLs: propagation constant, characteristic impedance, phase velocity, wavelength, coordinate dependent current and voltage, signal reflection and transmission.

Circuit analysis using current and voltage phasors. Generator and load with complex impedance, and impedance matching (reflection coefficient, power transmission coefficient). Smith Chart as a design tool for impedance transforming circuits.

Definition of scattering parameters (S-parameters) for two-port networks. Input and output reflection coefficient of a two-port and simultaneous impedance matching principle.

Plane wave propagation basics. Elliptical, circular, and linear polarization of a plane wave. Radiation intensity, power density, and Poynting vector.

Basic antenna parameters: beamwidth, radiation patterns (normalized field pattern and power pattern), directivity, gain, realized gain, radiation efficiency, antenna impedance.

Radiation from fixed current density: Vector potential, radiation integral, parallel ray approximation.

Key-features and design principles of elementary wire antennas (impedance and radiation pattern versus wire length), including dipole and monopole, simple uniform linear arrays (beam steering and patter shaping, visible region, pattern multiplication principle, directivity), and a regular microstrip patch antenna (transmission line model, feeding techniques).

Complementary knowledge:

Theory of L-section matching.
Matching with a straight TL section.
Lossy transmission lines.
Gain definitions using S-parameters: power gain, available power gain, transducer gain, maximum available power.
Non-uniform linear arrays.
Mutual polarization efficiency and axial ratio measurement.
Receiving antennas and Lorentz reciprocity theorem.