Applied RF Techniques I
Course 001
| Greenbelt, MD | Oct 18-Oct 22, 2010 |
| Course 001-4280 | Presented by Bob Froelich |
Register by 9/13/2010 and pay $1995, otherwise pay $2195  | |
| San Jose, CA | Mar 21-Mar 25, 2011 |
| Course 001-4345 | Presented by Bob Froelich |
| Register by 2/14/2011 and pay $1995, otherwise pay $2195 | |
Summary:
Switching from traditional definitions based on voltages and currents, to power-flow concepts and scattering parameters, the course has smooth transition into the wireless domain. We review S-parameter measurements and applications for both single-ended (unbalanced) and balanced circuits and have a brief introduction to RF systems and their components. Impedance matching is vitally important in RF systems and we use both graphical (Smith Chart ) and analytical techniques throughout the course. We also examine discrete and monolithic component models in their physical forms, discussing parasitic effects and losses, revealing reasons why circuit elements behave in surprising manners at RF.Filters, resonant circuits and their applications are reviewed through filter tables and modern synthesis techniques, leading into matching networks and matching filter structures. Since wires and printed circuit conductors may behave as transmission line elements, we also cover microstrip and stripline realizations. 2D and 2,5D electromagnetic field simulators are used in the course to illustrate transmission line behavior and component coupling effects.
In the area of active circuits, we first examine fundamental limitations posed by noise and distortion. The next topic is small-signal linear amplifier design, based on scattering parameter techniques, considering input/output match and gain flatness RF stability is examined both with S-parameters and also with the Nyquist test using nonlinear device models. Since DC biasing affects RF performance, we review active and passive bias circuits and see how they can be combined with impedance matching circuits. Another important consideration is circuit layout, therefore we look at problems caused by coupling, grounding and parasitic resistance. Narrow- and broadband designs are compared, using lossless and lossy impedance matching as well as feedback circuits. Low-noise amplifier design is illustrated, discussing trade-offs among gain flatness, noise, RF stability, and impedance match. Harmonic and inter-modulation performance is also examined. Performance trade-offs of balanced amplifiers are viewed. The course concludes by examining large-signal and ultra wideband feedback amplifiers.
Students are encouraged to bring their laptop computers to class. The design software available for use in this public course is from Applied Wave Research (AWR).
Learning Objectives:
Upon completing the course, the participant will be able to:• Describe RF circuit parameters and terminology.
• State the effects of parasitics on circuit performance at RF.
• Use graphical design techniques and the Smith Chart.
• Match impedances and perform transformations.
• Design filters with lumped and distributed components.
• Perform statistical analysis: design centering, yield optimization.
• Predict RF circuit stability and stabilize circuits.
• Design various RF amplifiers: small-signal, low-noise, and feedback.
Target Audience:
The course is designed for practicing engineers who are involved with the production, test, and development of RF/Wireless components, circuits, sub-systems, and systems, in the 100-4000 MHz frequency range. It is equally useful to new engineers and to those who may have practical experience but have not had opportunity of getting a thorough foundation of modern, computer-oriented RF circuit techniques.
Engineering degree or at least three years applicable practical experience is recommended.
Outline:
Day One
Introduction to RF Circuits and Components• Two-terminal impedance/admittance parameters • Power-flow and travelling wave concepts • Reflection coefficient, VSWR • Return loss & mismatch loss definitions • Applications of the Smith Chart • The dual (immitance) Smith Chart • RLC component manipulations • Constant Q curves and bandwidth relation to Q • Negative resistance and compressed Smith Chart • Illustrative examples: graphical Smith Chart manipulations • Scattering (S) and (T) parameters • Mixed-mode S-parameters for balanced circuits and RFIC's • Transistor datasheets and RF device parameters • Network analyzer measurements and de-embedding
Day Two
Impedance Matching and Component Models• Network order and transmission zeroes • Maximum RF power transfer • Conjugate match with real/complex terminations • Bandwidth considerations • Impedance matching of balanced circuits • Impedance matching using transmission lines on the Smith Chart • Illustrative examples: Narrow & broadband impedance matching • Discrete component equivalent circuit models • Comparison of discrete and monolithic component models • Component losses and parasitics • Test fixtures and de-embedding • Grounding techniques and parasitics; resonant circuits • Loaded and unloaded Q's and their effects on bandwidth • FR-4 vs. newer printed-circuit board materials • Transmission line structures: micro-strip, strip-line, and coaxial forms • Losses end discontinuities, shielding, coupling and top-cover effects • Illustrative examples: modeling of RF inductors, resistors, and capacitors
Day Three
Filters, Resonant Circuits, and RF CAE• Various filter response realizations • Selectivity vs. group-delay distortion • Primary and secondary component resonance effects • Transformations to highpass, bandpass and bandstop response • Diplexer filters and examples • Linear and nonlinear circuit analysis • Circuit optimization: gradient and random techniques • Illustrative example: Optimization of a broadband matching network • Circuit synthesis and Norton transformations • Monte Carlo analysis and yield optimization; design centering • Nominal vs. statistical sensitivities • Continuous and discrete-step yield optimization • Circuit design with physical components • Optimum design strategy with modern CAE • "Low-Budget" versus "Full-Feature" CAE • Illustrative example: Yield optimization of a lowpass filters
Day Four
Active RF Circuit Design• Harmonic and inter-modulation distortion • Gain compression and dynamic range • Linear vs. nonlinear amplifier design considerations • Unilateral Power-Gain circles and amplifier design • Unilateral Figure-of-Merit and bilateral design • RF circuit stability: graphical and analytical techniques • Nyquist stability criteria • Device stabilization: Feedback vs. cascade loading • Illustrative example: Broadband transistor stabilization • Stability of cascaded amplifiers • Simultaneous conjugate match; bandwidth considerations • GMAX and MSG definition • Topology selection; layout effects on performance • Multistage amplifier design techniques • Illustrative example: 1900MHz amplifier design for maximum gain
Day Five
Low-Noise and Broadband Amplifiers• Transducer-, operating-, and available-gain techniques • Linear Power amplifier stabilization • RF noise sources, noise figure and noise measure • Constant-noise and constant-gain circles in LNA design • Available-gain design for minimum noise • Trade-offs between gain, match, and noise performance • Illustrative example: 900MHz LNA design • Balanced amplifiers • Active and passive DC bias circuits • Layout and ground considerations • Broadband amplifier design techniques • Reactive mismatch and lossy matching techniques • Cascade equalization • Feedback amplifiers combined with impedance matching • Circuit optimization for gain, match and stability • Feedback effects on stability and noise • Illustrative Example: 1-4000 MHz feedback amplifier design
Summary and Conclusions
Subject Areas Covered
RF Circuit Design (Linear): S-Parameters, Smith Chart, Passive Components, LNA'sMixed Mode Balanced Circuit Techniques
Fundamental RF Circuit Concepts & Parameters
RF & Wireless Circuit Components
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