Attend Lab 5: Single Stub Matching

  • Due No Due Date
  • Points 100

ECE 3305 Lab 5Single Stub Matching

Introduction

In this lab, we will evaluate a 50-ohm microstrip (it's already soldered to the board for us), build a monopole antenna, and match it with a single stub matching network  at 900 MHz. Your goal should be a match of -20 dB or better somewhere close to 900 MHz. Have fun!

Pre-Lab: Please complete the pre-lab assignments each week before coming to the lab.

Lab attendance: Lab attendance is required this week in order to complete the measurements. If you are unable to attend your lab due to illness, please contact your TA and arrange a later date to complete this lab.

No lab next week: Next week, there is no in person lab, and you can use that time to write your report.

What is due: The report for this lab is due  before your next lab.

 

PRE-Lab

Download Files for Lab 5

Please download the following files and bring them with you to the lab (preferably on your laptop).

you will need

  • scissors
  • scotch tape
  • wooden pencil with eraser
  • calipers or metric ruler (to mm scale)
  • Wire cutters

Pre-Lab

  • Read
  • Review Single Stub Matching. We will be using a parallel (shunt) open circuited stub.

Support Materials

Part 1. Microstrip Line

A microstrip sandwiches an insulating substrate material (thickness h and permittivity er) between a top conductor (width w) and ground plane. There are several (several!) approximations for the characteristic impedance (Zo) as a function of these parameters. All are based on empirical measurements, fit to a set of equations. None are exact. We'll use the equations from your textbook, but others could have been used instead.

Reading:

Extra Support Materials

 

Part 2. Monopole Antenna

Video showing wire monopoles similar to what we'll be building in the lab. The video discusses SWR (standing wave ratio, in your textbook this is called VSWR). We want this to be as low as possible (1 is the lowest it can be). The video also shows the Smith charts, and where the antenna is resonant along the horizontal axis.

Extra support materials

Monopole Antenna Links to an external site.

Part 3. Single Stub Match

Reading (Review from Lecture Class)

extra supporting material

 

Part 4. Writing a Good Conclusion

When writing a conclusion, summarize what the lab was about, and the main observations from the lab. A list of observations to comment on is included in the lab handout. Be specific (give values).

A good example of a conclusion on a paper using dual-band stub matching can be seen here> Dual-Band_Impedance_Transformer_Using_Two-Section_Shunt_Stubs.pdf Download Dual-Band_Impedance_Transformer_Using_Two-Section_Shunt_Stubs.pdf To make this conclusion even better, it would have been good if the authors had included values rather than just saying the match is good.

 

TURN IN

  • Attendance is required. 100 points will be given for your attendance.
  • Report: For the report this week, fill in the blanks, boxes, and answer the questions in the lab handout. Your conclusion (to be included in the handout) will be the special focus of grading this week. Turn in your report before your next lab: Turn in Lab 5: Single Stub Matching

 

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