1. EEE161 Lab Plan
As of 11/13/2017

2. Today & Next 2 labs 11/13 & 11/14 Lab 8
All student groups look at RK’s boards
Take photos of the labels & measure the thickness
Prepare for “Patch … Project” to be done on 11/20 & 21
11/20 & 11/21 “Patch … Project”
All groups design a patch antenna at 2.5 GHz
I will select best patch of the whole lab for fabrication
We have material for 1 patch per lab class
The patch group will build & test the patch
3 groups build ¼ wave monopoles
1 group will research a QRH¹, measure one we have, & report on it
11/27 & 11/28
Fabricate the patches and monopoles
Take impedance measurements if you are ready
Locate the resonant frequency
The QRH group can measure its impedance up to 3 GHz
1. The best knock-off of Ray Frank’s awesome original wide band Quad Ridge Horn (QRH) design is shown on page 37 & 38 of the Satimo/Orbit/FR catalog. We have 3 of the original prototypes developed between 1960 and 1970 on loan from Northrop Grumman.

3. Last EEE161 Lab in the Antenna Lab, Santa Clara 1119 D
 12/4 & 12/5
Each group gets ½ hour for impedance and ½ hour for patterns
1. QRH group goes first with patterns; impedance not needed 12:00
2. Patch group starts with impedance :00
3. Monopole 1 group starts impedance while patch group takes patterns 12:30
4. Monopole 2 group starts impedance while monopole 1 group takes patterns 1:00
5. Monopole 3 group starts impedance while monopole 2 group takes patterns 1:30
6. Monopole 3 group takes patterns 2:00
7. Finish ………………………………………………………………………………………………………… 2:30
Finals week
Lab groups turn in lab reports to SacCT with a minimum of:
1) A photo of your group’s antenna
2) Center frequency from impedance test
3) Plots of azimuth & elevation patterns
from the .xls text files generated by the anechoic chamber computer
Each group bring a thumb drive on 12/4 or 12/5 to get the data from the chamber computer “Quiet”. The file names include the date and time.
Select “yes” to open the text file in an Excel style format
Use Matlab, or Excel, etc. to plot or,
Use a pencil to connect dots every 10⁰ on polar graph paper

4. Typical Dielectrics Useful for Making Antennas
We have Duroid
and FR4
Check our material labels and thickness for Lab 8 part III
The copper that does not look like an antenna can be manually peeled off the FR4 with pliers

5. Lab 8: Microstrip Matching Design & Layout
Lab 8 Part I use Z₀₂ = √(Zpatch * Z₀)
Z₀ = 332+j0 OR Z₀ = 119+j0
F = 2.5 GHz (change ADS Default from 1 GHz in step 8)
Lab 8 Part II Fabrication methods
Mechanical Milling
We have a T-Tech router
We can borrow a different router
In some materials we can scribe the patch outline & peel unwanted copper
We have a facility for etching
We could use a commercial vendor
Lab 8 Part III Each Group design a matching network using the following two designs:
1) A quarter wave line at Z₀₂ as shown in Ulaby fig (a) page 102
Z₀₂ = √(Zpatch * Z₀) note square root √
2) A matching stub at d₁ on a 50Ω (Z₀) line as shown in fig (e)
The matching line in case 1 may be too thin for manufacturing tolerances, if so we would need to use case 2
The matching network is needed for the patch antenna

6. Lab # “Patch Antenna Design, Fabrication, and Measurement Project”
Each Group Pick a material now
Select the Duroid, or FR4
Record the dielectric constant and thickness
The FR4 we have may not be Taconic but that is ok
FR4 εᵣ will be between 4.2 and 4.9 depending on the amount of resin
Next week design a patch using ADS Momentum
Use your matching network from Lab 8 with the same material
L = 0.49 λ/√εᵣ (L is just under ½ Wavelength)
Zin = [90 εᵣ²/(εᵣ-1)](L/W)² → calculates M1
2 equations with 4 unknowns
We need to preselect 2, i.e. λ and εᵣ
The Patch Project specifies a square patch
L = W is a square patch
We can then solve for Zin
This is shown on the next 2 slides
Figure 1 (b) from “Patch Antenna …” p.2

7. Zin is the point where the antenna impedance crosses the Smith chart real axis
363 Ω 

8. Zin is the point where the antenna impedance crosses the Smith chart real axis
520 Ω 

9. Design a Patch Antenna at F = 2.5 GHz W/ADS
Elevation Front to Back & Edge on
> ~1 λ W
≥ 0.1 λ L
Patch
Azimuth, V pol. or H pol. ?
Feed line Z₀₂ or 50Ω TBD
Ground Plane
Label the back side
Matching stub TBD
Feed point
Connector
Patch Lab, determine if the antenna polarization (pol.) is Vertical (V↑) or Horizontal (H→)

10. Quad Ridge Horn (QRH) Antenna Under Test (AUT)
Anechoic Chamber
Northrop Grumman 2-18 GHz QRH Antenna
Mounting Stand
Preamplifier
Detector
Azimuth Rotator
Walk-on Absorber

11. 3 Groups Design, Build, & Test a Monopole at 2.5 GHz
λ/4 Radiator
Ground Plane
1 wavelength (1λ)min.
Round, Square, or Random

12. Antenna Lab Test Equipment
Network Analyzer
Positioner Controller
Signal Generator
Quiet Computer
Cable E
Detector
Equipment drawer

13. Available Circuit Material
RT Duroid 5880
εᵣ = 2.2, H = 0.062”
εᵣ = 2.2, H = 0.031”
FR4
εᵣ = 4,5, H = 0.059”
Label back of your Patch