EEE161 Lab Plan As of 11/13/2017

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. http://www.satimo.com/sites/www.satimo.com/files/Closed_Wideband_2013.pdf

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 12:00 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

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

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. 2.33 (a) page 102 Z₀₂ = √(Zpatch * Z₀) note square root √ 2) A matching stub at d₁ on a 50Ω (Z₀) line as shown in fig. 2.33 (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

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

Zin is the point where the antenna impedance crosses the Smith chart real axis 138 Ω ----------

Zin is the point where the antenna impedance crosses the Smith chart real axis 332 Ω ----------

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→)

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

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

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

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