High Frequency Techniques
FEKT-BKC-VFTAcad. year: 2019/2020
The course is focused on design basics of passive and active high frequency circuits working up to approx. 3 GHz. First part is dedicated to passive circuits: resonant circuits and matching networks, attenuators, splitters, combiners and HF switches. Second part is focused on amplifiers, mixers, oscillators and frequency synthesizers.
Learning outcomes of the course unit
After successful passing the final exam, the student should be able to:
- calculate power, voltage and current levels in decibels
- describe important electrical parameters of wire, coil and capacitor from the high frequency point of view
- explain behavior and electrical parameters of series and parallel resonant circuit as well as coupled resonant circuits
- explain principle and show examples of lumped element filters
- using the Smith chart, explain principle of impedance transformation with parallel resonant circuit, L-network, T-network and PI-network
- explain principle and describe important parameters of attenuator, HF power combiner and switch
- explain terms: stability and gain of linearized amplifier
- explain and calculate with important parameter of amplifier (dynamic range, intercept point, 1dB compression, noise figure)
- explain terms: mixer and its output spectrum, conversion loss, conversion gain, image frequency and draw basic mixer schematics
- explain principle of feedback oscillators and draw basic schematics of LC and crystal oscillators
- explain terms: phase noise and stability of HF signal
- draw basic schematics of PLL and DDS syntehsizers
- explain principle and important parameters of PLL and DDS systems
The student should be able to:
- explain basics of electronic circuits and electromagnetic waves and transmission lines (inductance, capacitance, impedance, reflection coefficient, Smith chart, standing wave ratio)
- analyze basic electronic circuits with passive components
- calculate with complex numbers and logarithms
Recommended optional programme components
Recommended or required reading
VÁGNER, P. Vysokofrekvenční technika. Skripta [online]. 2013 [cit. 2017-08-12]. Dostupné z elearningových stránek předmětu. (CS)
RADMANESH, M., M. RF & Microwave Design Essentials. AuthorHouse 2007. (EN)
ŽALUD, V. Moderní radioelektronika. Vydavatelství BEN, Praha 2000 (CS)
Planned learning activities and teaching methods
Techning methods include lectures and practical laboratories.
Teaching methods depend on the type of course unit as specified in the article 7 of BUT Rules for Studies and Examinations.
Assesment methods and criteria linked to learning outcomes
- homework: 16 points (2 homeworks x 8 points)
- measurements in laboratory: 8 points (2 exercises x 4 pts)
- written tests: 1x10 points
- final exam: 66 points
The final exam consists of 2 parts: 30 points in theoretical part, 36 points in numerical examples. The student must get min. half points of each part to pass the exam successfully.
Language of instruction
1. Gain and signal level. Series and parallel resonant circuit.
2. Impedance transformation using parallel resonant circuit.
3. Coupled resonant circuits. Power and impedance matching using RLC circuits.
4. Power splitters and combiners, attenuators and HF switches.
5. Linearized transistor model. S-parameters.
6. Stability, stability circles, gain, constant gain circles.
7. Noise in circuits. Noise temperature, noise figure. Noise matching.
8. Narrowband and broadband amplifier. Low noise amplifier.
9. Large signal amplifier. Operating classes, main parameters.
10. Mixer and its output spectrum, mixer parameters. Mixer schematics.
11. Transistor oscillators, fixed and tunable oscillators.
12. Phase locked loop. PLL synthesizers.
13. Direct digital synthesis DDS.
The aim of the course is to make students familiar with basics of passive and active high frequency circuits.
Specification of controlled education, way of implementation and compensation for absences
Evaluation of activities is specified by a regulation, which is issued by the lecturer responsible for the course annually.