ECE 5321/6323 LEARNING MATERIALS 2D -- RF Filters Stepped Impedance Design

Introduction

In this module, we will be learning about RF filters and how to design them using the Insertion Loss method.

2A: We will begin with the basics of lumped element filters, which are applicable at lower frequencies as well as RF frequencies. We will review low pass, high pass, band pass, and band stop filters, and how to implement low pass filters with maximally flat (Butterworth), equal ripple (Chebyshev), and Elliptic designs.

2B: We will then learn how to convert the LP designs to HP, BP, BS designs, still with lumped elements.

2C: Next, we will learn how to convert the lumped element designs to distributed designs using stubs and 2D: stepped impedances. Finally, we have information on practical implementation issues.

Learning Materials

Readings

Microwave Engineering by David M. Pozar -- Chapter 8.6
Planar Microwave Engineering by Thomas Lee (textbook, see Canvas online Bookshelf) -- Parts of Chapter 23
RF Circuit Design by Chris Bowick -- Chapter 3 (has detailed tables for Butterworth and Chebyshev filters)

Material/Lecture content

Topic 2D: RF Filter Implementation (Stepped impedance)

STEPPED Impedance Filters

Stepped Impedance Low Pass Filters for Maximally Flat (Butterworth) Design N=6 (RF Design Basics)

https://www.youtube.com/watch?v=p_P6muNgUtc

Design and Simulation of Stepped Impedance Low Pass Filters for Maximally Flat (Butterworth) Design N=6 (RF Design Basics)

https://www.youtube.com/watch?v=fNXLrApAGeY

Topic 3: Practical Considerations

Goal: Understand prototyping, measurement, practical considerations

Rapid Prototyping of RF Filters

https://www.youtube.com/watch?v=drwGvATLNaw

Example of a Hairpin Filter

https://www.youtube.com/watch?v=xsbRrNJnmgA

How to use a NanoVNA to measure LP Filter

https://www.youtube.com/watch?v=F17mN5uuzGY

What could possibly go wrong??

Practical RF Filter Design and Construction

https://www.youtube.com/watch?v=1sq8Cvju2Oo

Practical PCB-Based RF Filter Design

https://www.youtube.com/watch?v=pBuJg7DBKQI

Supporting Material

Review: What are S-parameters?

They represent reflection and transmission coefficients.

https://en.wikipedia.org/wiki/Scattering_parameters

https://www.youtube.com/watch?v=-Pi0UbErHTY

Review: What are ABCD Parameters?

(This matrix allows you to calculated cascades of series networks just by multiplying the ABCD matrix. These can easily be converted to/from S-parameters.)

https://circuitglobe.com/abcd-parameters-of-transmission-line.html
https://www.youtube.com/watch?v=qnHaOwYfzgE
Relationship between ABCD and S-parameters https://www.microwaves101.com/encyclopedias/abcd-parameters

Review: Review: What are Z-Parameters?

https://en.wikipedia.org/wiki/Impedance_parameters

Review: Converting between ABCD, S, Z parameters

https://www.rfcafe.com/references/electrical/s-h-y-z.htm

Review: dB

Decibels
dB on a Spectrum Analyzer
https://www.youtube.com/watch?v=1mulRI-EZ80

Review: Finding Microstrip width and wavelength

Microstrip Transmission Line

Filter Design Calculators (check your work with these)

LC Design Tool
- https://rf-tools.com/lc-filter/description.html
- https://rf-tools.com/lc-filter/
Butterworth Design Tool
- http://www.calculatoredge.com/electronics/bw%20pi%20low%20pass.htm
Chebyshev Design Tool<< This one is modified Chebyshev, not the same ones as in our tables.
- http://www.calculatoredge.com/electronics/ch%20pi%20low%20pass.htm
Other Circuit Calculators
- http://www.calculatoredge.com/index.htm#electrical

Dr. Furse's Filter Design Cookbook

Filter Design Handbook (Furse).pdf

Class LIVE VIDEO Meetings

We'll meet Tuesday and Thursday 1230-145. Use the Zoom link to the left. If you can't find the link under upcoming meetings, it will be under Previous meetings. Use the same zoom link for every class and office hours.

Notes for Today: Stepped Impedance Filters.pdf

PPT to take notes on:2D Stepped Impedance Filterss.pdf

Useful handout to print out 2D Handout for Class.docx

Microstrip Calculator:

Activities

You can access the activities by clicking "next" below or through the navigation links at the top of the page.

This module is 2 weeks long. Earn 100 total points for this module from some combination of the following:

Module 2: Assignment 2d Converting Lumped Element Designs to Stepped Impedance Filter (20 pts)
Module 2: Tutorial -- RF Filters (20 points, plus 10 points extra credit)
- Note: You may do up to three tutorials, provided they are significantly different. (For instance, designing with Butterworth and then with Chebyshev is too similar, but designing with Butterworth, and then converting from LP to HP, is significantly different.) You can get credit for multiple tutorials simply by adding additional posts to this discussion board.
Module 2 -- Filters: Muddiest Point Discussion (10 pts)
Module 2: Class Feedback (10 pts)