ELT-47266 Active RF Circuits, 5 cr

Additional information

Suitable for postgraduate studies.

Person responsible

Mikko Valkama, Olli-Pekka Lunden


Implementation Period Person responsible Requirements
ELT-47266 2019-01 1 - 2 Olli-Pekka Lunden
Mikko Valkama
In order to pass this course, students collect points from various activities, including, but not restricted to, (1) homework submissions, (2) weekly tests, (3) seminar presentations, and (4) seminar report. There is no exam in this course.

Learning Outcomes

Each year the course implementation has a special, focused "theme", i.e., some practical system or application. The course teaches key concepts with a direct connection to the practical application. The theme may change from year to year, or, it may stay the same for several years. In 2016 and 2018 the theme was "Wireless Sound Transmitter for Electrical Guitars". The course contents, however do not change much from year to year since the very key concepts are common in all RF applications. AFTER COMPLETING THE COURSE, student will understand and will be able to apply common, basic RF circuit design concepts. Student will be able to analyze and design some active RF circuits such as RF amplifiers, RF oscillators, or RF mixers, for example. In addition, student will have the ability to give a presentation and produce a technical report about a topic in RF electronics.


Content Core content Complementary knowledge Specialist knowledge
1. RF transistor amplifiers: Transistor modeling using linear circuit parameters (Y, Z, S and ABCD), small-signal equivalent circuits, and nonlinear ("spice") models. Stability against oscillation. Impedance matching of two-ports, noise figure optimization, linearity.   Matlab RF toolbox, RF circuit simulations. Aspects in practical implementations.   
2. RF oscillator design: modeling an oscillator as 1) a positive feedback amplifier and 2) as a negative resistance device. Clapp-type (single transistor) and cross-coupled (two-transistor) oscillators. Frequency control using varactors (aka "varicaps" or "capacitance diodes") Crystal oscillators. Design rules-of-thumb and their origins.  Frequency stability, jitter and phase noise. DC-to-RF efficiency.   Oscillator design trade-offs and optimization.  
3. RF mixers: understanding mixer as 1) a circuit made of one or more switches 2) a circuit made of one or more nonlinear components. Active and passive mixers. Conversion loss/gain, mixing products (the wanted and unwanted output frequencies), linearity, port-to-port isolation.   Mixer noise figure.   
4. Larger entities: RF systems such as "receiver chain" and the "phase locked loop".  Other active RF circuits: frequency dividers, prescalers, frequency multipliers, phase detectors, the phase locked loop (PLL), modulators, demodulators.    

Instructions for students on how to achieve the learning outcomes

(1) Designing active RF circuits is "something else". It's fascinating and fun. This course introduces you to the RF designer's world. The intention is that you will understand clearly most of the key issues in the heart of RF engineering. Having tasted that feeling of strong competence, you grow your confidence so that you're ready to dig into anything new. (2) According to the feedback from previous years, this course is somewhat revised for 2015. Most praised learning activities are preserved while some contents are cut out. The true work load was adjusted to correspond 5 cr. (3) The class room activities take place on the first period, only. The main activity is creating a presentation and a seminar report of own topic. This work starts from the beginning of the period. The presentation builds up step by step throughout the whole period. You will get help from peers and the teacher. During the seven weeks you have plenty of time to make your presentation perfect. Preparing and giving a clear presentation on a topic is one of the best ways to make sure you have understood your topic. And others will understand also! (4) It is strongly recommended (but not mandatory) that students take this course together with ELT-47286 RF Project. These courses support each other nicely.

Assessment scale:

Numerical evaluation scale (0-5)

Partial passing:

Completion parts must belong to the same implementation

Study material

Type Name Author ISBN URL Additional information Examination material
Book   Microwave Engineering, 4th ed   David M. Pozar   1118213637, 9781118213636     John Wiley & Sons, 2011   No   
Book   Microwave Transistor Amplifiers Analysis and Design   Guillermo Gonzales       Second Edition, Prentice Hall, 1997.   No   
Book   RF Circuit Design: Theory and Applications, 2nd ed   Reinhold Ludwig, Gene Bogdanov   0131471376, 9780131471375     Pearson 2007   No   
Book   RF Design Guide, Systems, Circuits, and Equations   Peter Vizmuller       Artech House, 1995.   No   


Course Mandatory/Advisable Description
ELT-41727 Practical RF Electronics: First Principles Applied Advisable   1
ELT-47206 Basics of RF Engineering Mandatory    

1 . ELT-41711 Johdatus suurtaajuustekniikkaan

Additional information about prerequisites
ELT-47206 Basics of RF Engineering is "mandatory prerequisite" (pakollinen esitieto), however, students with sufficient previous knowledge can be enrolled after an interview and/or test.

Correspondence of content

Course Corresponds course  Description 
ELT-47266 Active RF Circuits, 5 cr ELE-6256 Active RF Circuits, 5 cr  

Updated by: Turjanmäki Pia, 04.03.2019