ELT-47206 Basics of RF Engineering, 5 cr
Person responsible
Olli-Pekka Lunden
Lessons
| Implementation | Period | Person responsible | Requirements |
| ELT-47206 2016-01 | 4 |
Olli-Pekka Lunden |
Student must pass the exam. The exam is an open book exam. (In Finnish: materiaalitentti). Students may use any printed or written materials on paper and any types of calculators except calculators of smart phones or other communication devices. No communication devices are allowed. Compass and set square with degrees scale (Finnish: harppi ja kulmaviivain) may be needed in the exam. |
Learning Outcomes
Upon completion of this course, the student is able to solve theoretical problems that relate to practical applications of RF engineering, transmission line theory, and circuit analysis. He or she is able to make meaningful use of the concepts, tools, and definitions mentioned in the core contents in new situations. The student does not have to memorize anything by heart. It is impossible to exactly and in detail list all the things the student is expected to be able to do to pass the course. However, an example that follows should help understand the requirements: After completing the course the student is able to find the input impedance of a 100-ohm transmission line that is terminated to an antenna whose feed point impedance is (15+j25) ohms. In addition the student is able to design a lossless impedance matching network for the antenna that allows maximum power transfer. Further, given a generator to feed the system, he or she is capable of calculating how much of the generator's available power is delivered to the antenna with and without the impedance matching network.
Content
| Content | Core content | Complementary knowledge | Specialist knowledge |
| 1. | TRANSMISSION LINE THEORY. Transmission lines: typical use and practical cables and planar structures. Lumped element model of a infinitesimally short segment of transmission line. Telegraph equations and their solutions plus their physical interpretation. Basic concepts: propagation constant, forward and reverse direction waves, characteristic impedance, phase velocity, wavelength, load reflection coefficient, reflection coefficient along the line and line input reflection coefficient, input impedance. Properties of quarter wave and half wave lines. Replacing inductors and capacitors with transmission line elements. Their effective capacitance and inductance, respectively. VSWR. Return loss and reflection (mismatch) loss. Reflection at impedance discontinuity. Voltage transmission coefficient. Transmission of voltage and power at the discontinuity. Generator properties: Thévenin equivalent and available power. Properties of lossy transmission lines. | Wave trap (bandstop filter). Transmission line filters in general. Effective dielectric constant of microstrip line and its relation to the wavelength in this media. | Multiple reflections. |
| 2. | SMITH CHART (SC). Normalized impedance. Drawing and reading impedances and reflection coefficients and other related parameters on the SC. Normalized admittance. Impedance locus as a function of frequency. | How the Smith chart is made? Mathematics behind it. | |
| 3. | IMPEDANCE MATCHING. The advantages of impedance matching. Impedance matching techniques: lumped element matching, distributed element matching, resistive vs. reactive matching. | Bandwidth of impedance matching. Free-ware design tools. | The relationship between RF/microwave filters and impedance matching networks. |
| 4. | SCATTERING (S) PARAMETERS AND GAIN CONCEPTS. Definition of S-parameters (as based on the forward and reverse voltage waves on transmission lines that are connected to each port of a linear two-port network). The reasons for and advantages of using S-parameters instead of other equivalent representations such as the y-, z- and h-parameters. Applications of S-parameters. Input impedance of a two-port as a function of its S-parameters and load impedance. Determination of S-parameters of simple (and arbitrary) S-networks. Definitions of gain conceps: power gain, available power gain, transducer power gain and their relation to S-parameters. | Unilateral transducer power gain (Gtu), maximum Gtu. | Unilateral figure if merit. |
Instructions for students on how to achieve the learning outcomes
Students are given the possibility and encouraged to do homework, thereby earning points that contribute to the final grade. It is possible, at least in theory, to pass the course without going to the exam, by submitting perfect homework solutions. However, the higher the exam points are, the less the homework point give contribute. In the evaluation of the homework and exam solutions the following guidelines are applied: 1) Does the student understand the main concepts, definitions, and tools 2) Is the student able to make meaningful use of them in solving new problems such as the example given above.
Assessment scale:
Numerical evaluation scale (0-5)
Prerequisites
| Course | Mandatory/Advisable | Description |
| ELT-21050 Transistorivahvistimet | Advisable | 1 |
| DEE-11000 Piirianalyysi | Advisable | 2 |
| ELT-41710 Johdatus suurtaajuustekniikkaan | Advisable | 3 |
1 . For foreign students: A basic course in analogue electronics.
2 . For foreign students: A basic course in network analysis.
3 . ELT-41727 Practical RF Electronics: First Principles Applied ELT-47426 Transmission Lines and Waveguides
Correspondence of content
| Course | Corresponds course | Description |
| ELT-47206 Basics of RF Engineering, 5 cr | ELE-6057 Basics of RF Engineering, 5 cr |