Course syllabus for Antenna engineering

• electric circuit theory
• complex non-differential vector analysis
• theory of electromagnetic fields and waves

1. Describe how antennas for line-of-sight (LOS) systems work and are characterized. Examples of LOS systems are radio telescopes, radar, radio links (point-to-point and point-to-multipoint communications) and satellite communication systems.
2. Describe how antennas in multipath environment with fading behave and are characterized, such as antennas for mobile terminals, i.e. mobile phones, including also the characterization of the whole mobile terminal and user interaction.
3. Describe the most common materials used in numerical antenna analysis as well as in practical antenna design.
4. Explain the different factors contributing to the efficiency and gain of different types of antennas, as well as to system noise temperature.
5. Explain the physical limitations of antennas; such as miniaturization and bandwidth limits of small antennas, maximum gain limits of large antennas, and correlation and efficiency limits of multiport/multibeam array antennas.
6. Explain how different antennas can be analyzed in terms of classical incremental elementary sources, by using a modern and compact non-differential vector notation and numerical integration. The incremental elementary sources are the electric current, the equivalent magnetic current and the directive Huygens source.
7. Apply your knowledge about antenna analysis to design antennas using classical formulas and design curves for the most traditional antenna types; such as dipoles, slots, microstrip patches, horns, reflectors and phased arrays. Good initial designs with classical formulas are important for a successful numerical design with a professional antenna CAD tool. And, to describe the same antennas according to §a and §b above.
8. Apply your knowledge about characterization of antennas for LOS and fading environment to measure antennas, both in classical anechoic chambers and in modern reverberation chambers, respectively. The reverberation chamber is a multipath emulator, in which also active mobile terminals such as mobile phones will be measured.

• Describe - to tell or depict in written or spoken words, without using the textbook;
• Explain - to make known in detail, including the simplest basic equations, without using the textbook.
  

1. Introduction: Course information. Examples of antenna and antenna types. Applications and brief history. Some existing and future antenna systems and their frequencies and antenna types. About antenna terminology. Repetition of dB and basic vector formulas (cross and scalar products).
2. Characterization of antennas for line-of-sight (LOS) systems: Plane waves. Linear and circular polarization. The radiation field function: Phase reference point, polarization, phase center, directivity, sidelobes, E- and H-planes. Rotationally symmetric antennas: BOR0 and BOR1 antennas (BOR = Bodies of Revolution). System characteristics: gain, efficiency, total radiated power, equivalent noise temperature and G/T. Equivalent circuits on transmit and receive. Antenna impedance and matching. Transmission between two antennas in free space. Antenna measurements.
3. Characterization of antennas for multipath environments: Multipath environment and Rayleigh fading. Single antennas: Mean effective gain, radiation efficiency. Multiport antenna systems: Embedded element patterns, embedded element radiation efficiency, mutual coupling and correlation. Antenna diversity: Apparent, actual and effective diversity gain. Maximum Shannon capacity of MIMO systems (Multiple Input Multiple Output). Characterization of active terminals: Total radiated power, receiver sensitivity and bit error rate (BER), realized diversity gain, and user interaction (head loss and specific absorption rate). Measurements in reverberation chamber. Transmission between two antennas in multipath.
4. Materials for antenna design: Theoretical materials and surfaces used in analysis: Perfect electric conductor (PEC), perfect magnetic conductor (PMC), PEC/PMC strip grids (soft and hard surfaces). Practical materials: Good conductors, poor conductors, dielectrics, foam. Artificial materials / periodic surfaces: Corrugations, strip-loaded surfaces, frequency selective surfaces (FSS), electromagnetic bandgap (EBG) surfaces.
5. Incremental elementary sources of radiation: The incremental electric current (Hertz dipole). The incremental equivalent magnetic current. The directive incremental Huygens source
6. Small antennas: Electric monopole and dipole. Yagi antennas. Log-periodic and other ultra wideband antennas. Electric loop antenna. Helical and spiral antennas. Slot antennas. Microstrip patch antennas. Inverted F-antennas or quarterwave patch antennas. Examples of practical small antennas for mobile terminals.
7. Aperture antennas: Aperture theory: aperture distribution, directivity, sidelobes. Tolerances and fundamental gain limitations of large antennas. Horn antennas: Pyramidal horns, conical horns, corrugated horns. Reflector antennas: Paraboloidal antennas, Cassegrain antennas, feeds, phase center, aperture illumination taper, diffraction, blockage, subefficiencies, sidelobes. Examples of antennas used in radio telescopes
8. Array antennas: Linear and planar phased arrays. Isolated and embedded element patterns. Array factor as element-by-element sum. Array factor as grating-lobe sum (aperture approach). Directivity, sidelobes and grating lobes. Mutual coupling, active antenna impedance and scan blindness. Fundamental efficiency and correlation limitations of multiport/multibeam arrays
9. Fundamental limitations: Fundamental directivity limitations of small and large antennas (including supergain). Miniaturization of antennas and their fundamental bandwidth limitations.
   

Lectures and tutorials: Each double hour lecture is followed by a double hour tutorial class, in which the course assistants will teach how to use the lectured principles, formulas and design curves to analyze and design antennas.

Three mandatory laboratory exercises: a) Measurements of radiation patterns of some antennas including planar phased array in anechoic chamber. b) Measurements of radiated power and bit error rate of mobile phone in free space and talk positions in reverberation chamber. Measurements of Rayleigh distribution and diversity gain in reverberation chamber. c) Design of microstrip antenna, realize it by metal tape and grounded substrate, and measurements of it.

Assignments: Four voluntary home assignments will be given. They give bonus points for the final result of the course exam, if solved and handed in.

A PDF version of the new extended edition of Prof Kildal's textbook "Foundations of Antennas - A Unified Approach for Line-Of-Sight and Multipath" can be downloaded for free from www.kildal.se subject to registration. The paper version of the book can be bought at Cremona. The notation in the book is compact, easily interpretable and well suited for this introductory course with emphasis on design and system performance of antennas.

The course material gives references to alternative descriptions in other textbooks.

The written exam consists of two parts. During the first part the students are not allowed to use the textbook, whereas during the second part the students are allowed to use the book including its graphs and tables. The exam consists of four problems that include several sub-problems. The limits of the 3, 4 and 5 grades of the final results for the course are set to 40 points, 60 points and 80 points, respectively, of written exam points plus Home Assignments bonus points and Study Visit bonus points.

The  written exam consists of 100 points. There are 11 Home Assignment bonus points for four accepted home assignments, and 4 Study Visit bonus points for participation in study visits at  RUAG / Saab Space and Bluetest (2 points for each).

All three laboratory exercises are mandatory to get pass the final exam.