IS2500  RFID Systems 2022


     Welcome to RFID Systems, IS2500!  This course is offered in period 1 during the 2022-2023 academic year. IS2500 is an applied engineering course on RFID technologies and systems.  The goal of the course is to familiarize you with all aspects of technology used in modern RFID systems, including near and far field varieties, and how to exploit RFID in your IT system and service designs.  We will discuss the physics, design, data structures and control mechanisms for RFID.  There is a very applied lab component to the course where you will design, build and deploy working RFID system components. If you are into maker-spaces and similar activities, then this course is for you. You will also be familiarized with associated standards, emerging business process models, applications, and social issues arising from the use of RFID. The textbook for this course is The RF in RFID by Daniel M. Dobkin, and published by Newnes.  

     Note that you don't need to have taken any courses in radio or radio theory to take IS2500!  Your undergraduate physics course will have given you enough background to enjoy the class.  The only danger is that you might end up really liking radios by the end of this course and want to build more on your own.


Schedule:

     Please check TimeEdit for the class starting times and locations.  Class times and locations are not always the same, so be sure to check early and often where and when a class session is.  If there are any special changes or exceptions to the schedule shown in TimeEdit then they are noted below, so be sure to also check this web page from time to time to keep current of any unexpected schedule changes that might occur.

Course schedule changes or problems.

No changes this week.

 Lecture Notes:
The lecture notes presented in class will always be available on this web site after the lecture that uses the notes has been given.

Project Lab:
The course includes a weekly project lab session.  All information for the labs will be available here.  During  the course it is updated weekly, so be sure to revisit it to get up to date information on the labs.

You can find the design rules for making PC boards that we can make in the Mentorspace here.

Week 35:  Introduction to RFID Systems
     During week 35 we start with an introduction to the course, and go over the goals of the course, logistics, practicalities and other expectations.  We then characterize the different kinds of RFID and look for the distinguishing characteristics of almost all RFID systems.  Because RFID systems are in effect radio systems, we will start to look at essential radio basics that will be necessary tools for our use during the course.  Note that you don't need to be a radio engineer or have taken a course in RF design to understand the material we will cover in the class.  In fact, you will probably discover as we go along that radio design in its basic forms is not difficult at all to understand, and actually starts to make the other classes you took in things like signal processing make a lot more intuitive sense!

Week 36:  Basic Radio

     During this week, we will look at the physics of radio that are relevant to RFID, both inductively and radiative coupled systems.  We will get a set of tools that help to describe the performance of RFID systems, and are a good way of expressing the performance/watt of  reader and tag combination.  Topics covered are how antennas work, ways to describe how power is transferred, how information is added to the signal, and how that changes the characteristics of the signal.  When this week is over, you will have a good idea of how to compute the expected range of an RFID system based and its data rate based on radio parameters.

 Homework for week 36:
Read chapters 1, 2 and 3 in the textbook
Do problems 2.1,2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, and 2.9

When you answer the problem questions, don't just say 'yes' or 'no' or some number.  Please explain WHY you are giving the answer you are giving in a way where you need to convince another person.  In real jobs and business, you will need to do this all the time.

This problem set is due by the end of the day on Tuesday, September 13, 2022.

Please submit your homework by emailing it to me in either PDF, Microsoft Word format (doc or docx) or as a LibreOffice Writer document (.odt).  Please don't use other formats as I will not be able to read them.  Also, please include your name as part of the homework file you email to me.  For example, Your_Name_Homework_1.odt.


Week 37:  Power exchange and Tags

      The questions now to look into are data and power related.  How much power does a fully passive tag need to operate?  How far away from a reader can such a tag be, and work correctly?  Not all that much power will be backscattered from the tag.  How can we know if it is enough for the receiver to hear it?   During this week and part of the next we will look at how RFID readers and tags communicate.  In addition to issues of modulation and coding, we will also look at link budgets and how power calculations are made to determine the amount of energy that can be exchanged between the RFID reader and the tag.  Ways to optimize power exchange, such as the use of directional antennas will also be covered.

Homework for week 37:

Do problems 3.1, 3.2, 3.3, 3.4  and also answer the following extra two questions:

1. A large corporate customer who makes secure RFID payment systems has asked you if it would be possible to design an inductively coupled RFID system that would only allow a tag to be read up to a distance of about 1 cm.  The customer wants the frequency of operation for the RFID system to be 2.4 Ghz, which is a high frequency.  Do you think this would be possible to do?  Be sure to explain why or why not.

2.  You have designed an equipment tracking system for another customer using radiative RFID, also running at 2.4 Ghz.  It works well, but the customer has complained that at about 12:00 every day, part of the system stops working.  After carefully looking for the cause, you have found that the company has microwave ovens in a kitchen that are used by the employees to warm up their lunches.  The radiation from the microwave ovens is also at a frequency of 2.4 Ghz, and interferes with the RFID readers that are close by.  Describe and explain two practical methods that you could use to solve this problem.  One thing the customer insists on is that the employees of the company be able to have a hot lunch, so throwing away the microwave ovens is not a good solution.
 
This problem set is due on Tuesday, September 20, 2022 before the end of the day.  Please submit your homework by emailing it to me in either PDF or Microsoft Word format (DOC or DOCX) or LibreOffice (ODT).  Please don't use other formats because I probably can't read them.  Also, please include your name as part of the homework file you email to me.  For example, Your_Name_Homework_2.odt.


Week 38:  Radio Architectures and RFID Applications

     It's important to understand architectural factors that can make a difference in RFID readers.  How do you know you are specifying a RFID reader that will perform well enough in your system solution?  The parameters we will look at will have an impact on  these aspects of the reader:
These parameters are fun to look at, not just in an RFID sense, but also with respect to radio in general.  Although you don't need to have a formal background in RF design to understand these topics, hopefully after going though this part of the course you will want to know more.  That, and maybe try building some radio circuits of your own.

     We will also start to discuss applications in this part of the course.  As we continue to look at technical issues, we will become a bit less centered on radio, and we will become more concerned with how the application space has impact on how a RFID system is designed and deployed.  The application space is growing at a very fast rate, and is a greatly influences the system requirements, both with respect to technology and cost.  As we will see in later parts of the course, the application space is putting pressure on other factors such as security that also have an impact on RFID systems.  But for now, we start with an examination of what the application space is about, and how it has benefit to industry and consumers.


Homework for week 38:

 Begin by doing problems 3.5 and 3.6 from the course textbook and be sure to show how you computed your answers.  Note that in some versions of the textbook, problem 3.5 refers to a "reader in problem (2) above".  That should say "reader in problem 3.4 above".  Also note that problem 3.6 may refer to a "problem (3) above".  If it says that, it really means "problem 3.5 above".

In addition to problems 3.5 and 3.6 answer the following extra three questions:

1. You are evaluating a radiative RFID system for use in a project. It has the following characteristics:

- It is radiative and operates at 915 Mhz.
- The reader's antenna is perfectly isotropic.
- The reader can transmit 1 watt of power.
- The reader's receive sensitivity is -60dBm.  (This much receive power is needed to read a tag's data.)
- The tag antenna is a half wave dipole.
- The tag needs 1 microwatt to operate.
- The tag's efficiency of converting RF energy into DC power is 70%.
- The tag can backscatter 2/3 as much power as it takes to power the operation of the tag.

Is this system forward or reverse path limited?  Show your calculations and how you arrived at your answers.

2. In this problem, you work for a company that makes RFID equipment, and your job is to design RFID readers.  The antenna designer in your group has just designed a new directional antenna that can be used with your RFID reader.  It provides an antenna gain of 8 dBi.  Government regulations that apply to your RFID reader say that it can radiate a maximum EIRP of 30 dBm.  What is the actual power in watts that your RFID reader can supply to this new directional antenna and still be within government regulations?  Show your calculations.

3. In this problem, suppose you wanted to use the directional antenna from problem 2 above with the RFID system from problem 1.  In other words, the perfectly isotropic antenna is now replaced with the directional antenna having a gain of 8 dBi.  Everything else about the RFID reader is the same and the tags that will be used are the same.  What is the forward link limited range of the resulting RFID system?  Show your calculations.

 This problem set is due brfore the end of the day on Monday, September 26, 2022.  In the usual way please submit your homework by emailing it to me in either PDF, Microsoft Word format (DOC or DOCX) or as a Libreoffice .ODT document.  Please don't use other formats as I will probably not be able to read them.  Also, please include your name as part of the homework file you email to me.  For example, Your_Name_Homework_3.doc.


Week 39:  Protocols


     This week we will look at at various protocols that are used with RFID systems.  Some of them are low level protocols, for example how multiple tags that are presented to a reader at the same time are sorted.  We also will look at higher level protocols like NFC.  Knowing these will help as you develop applications around RFID.

     Please be sure to start on your projects.  We will also talk about the project logistics more this week, and you will give your first overview presentation on Friday.  If you haven't already seen them, here are the readings from last week.  The user name and password to access them is given out in class.  There are three articles in this reading set that you may find very interesting.  The information in them may be useful for your projects.  Also, the ideas in the readings may give you ideas for future projects and products of your own.

There will be one more homework assignment given out next week.


 Week 40: RFID Security and Protocols
     Last week we started to talk about security and RFID.  Solutions using a hardware approach to security may be a large growth area for RFID in the future, so we will look at the basics of security primarily from a hardware point of view.  As we finish discussing applications for RFID it should become clear that the overall lack of security in RFID systems and applications cause a number of problems, both for businesses that want to use RFID, and for the customers of those businesses.

     This week we will also look at at various protocols that are used with RFID systems.  Some of them are low level protocols, for example how multiple tags that are presented to a reader at the same time are sorted.  We also will look at higher level protocols like NFC.  Knowing these will help as you develop applications around RFID.  We also will continue working on the projects.

Homework for week 40:

     There is also a homework assignment for week 40.  There are 4 questions in this homework set and they are already in a (hopefully) useful format.  You can find a microsoft word version here, a LibreOffice version here, and a plain text version here.   This problem set is due by the end of the day on Tuesday, October 11.  In the usual way please submit your homework by emailing it to me.  Be sure to include your name as part of the homework file you email to me.  For example, Your_Name_homework_4.odt.


Week 41: RFID Security

    This week we will continue with RFID and hardware security topics.  If you would like a copy of the notes about how to write good technical progress reports for industry, you can find them here.  And, we will continue working on the projects.


Presentation, Demo, and Final Report for week 42:


Presentation and demo:

 The project in its final form plus demonstration of complete parts of the project is scheduled to take place on Friday, October 21 starting at 14:00 the Mentorspace.  The presentation covers the entire project to the extent that your group has completed it.  It should include the following points:
  1. A description of the RFID project you have decided to implement.  Be sure to explain why the application is useful, and how it uses RFID.
  2. A description of the software and hardware architecture you have used to implement your project.  This description should have block diagrams of your system, hardware schematics, software flowcharts and listings, and other information about how you implemented your system and application.
  3. Data that shows how your design performs.
  4. Interpret your data and describe how well the project works. 

The entire presentation should take about 15 minutes.  Following that will be a demonstration of as much of the product as you have completed.   Everyone in your project group should give some part of the presentation.

Final Written Report:

You also will need to hand in a full report about your project.  Here is a list of what the report should include. The report is similar to the presentation, but should go into much more detail.  Also note the instructions for items #4 and #5 below
  1. A description of the system and application you have decided to implement.  Be sure to explain why the application is useful, and how it uses RFID.
  2. A complete description of the software and hardware architecture you have used to implement your project.  This description should have block diagrams of your system, hardware schematics, software flowcharts and listings, and other information about how you implemented your system and application, especially for the parts that use RFID.
  3. Data that shows how your design performs.
  4. A table that clearly explains who in your team did what in order to accomplish items 2 and 3 in this list.
  5. Conclusions about your design.  This needs to be done individually..  Interpret your data and describe how well the application works.  Explain performance, especially in terms of things relevant to RFID such as distances over which tags can be read, data rates, reliability or system variability, and estimate of cost.  Critique your design.  Do you think people would buy it?  How much money might they spend to buy it?  How would you improve your design?  What would you do differently if you were to re-design it?
     Each project group only hands in one final written report.  It is due before the end of the day on Monday, October 24, 2022.   In the list above, items 1 through 4 should be included in the final report as a group.  However, each group member should write item 5 individually.  You can attach it to the group report or send it to me separately, but be sure that you send it.  Be sure to put your name on your individual conclusion section.  This is a chance to think analytically and critically about what you did, what your results were, and how you would exploit or improve on them.

Please email your report and individual conclusions to me on or before the due date.   Your writeup can be in any of the usual formats: PDF, DOC, DOCX or ODT.  Be sure to send me email with any questions that you might have!