1. ECE 453 Lab 1 High-Frequency Component Models
Serge Minin

2. Pre-lab quiz How many winds are needed to make a 2.2uH
inductor with a T-44-6 core
What is the parasitic capacitance that causes a
resonance of 200 MHz for the above inductor.

3. Learning objectives
After this lab session students should be able to articulate what they will be doing in lab throughout the semester and how they will be graded. They should also be able to use basic functionalities of the simulation program (ADS) and an instrument for measurement of RF components (Network Analyzer). More specifically, they should know how to simulate an RLC circuit in ADS to obtain its impedance as a function of frequency, and to convert that impedance into the frequency-dependent reflection coefficient (assuming a 50Ω reference). With regards to measurement, they should learn how to calibrate a Network Analyzer up to 500 MHz for one-port reflection coefficient measurements, how to conduct such measurements at different frequency scales, and how to convert them to display in ADS as complex impedances. The students should also learn how to model as ideal RLCs two reactive components, a Quartz crystal (later used in an oscillator) and a toroid inductor (later used in a filter matching network), and to characterize their resonant behaviors. The students should learn how to construct the above inductor.

4. Lab tasks Next time Model several components based on provided data
Start on spectrum exploration with VSA
Today
Wind 2.2 uH inductor
Go through ADS tutorial/Xtal model
Calibrate NA, measure inductor
Calibrate NA, measure Xtal

5. Construction of inductors
Background
core confines field
fewer turns
Look up the cores
Calculate N of turns
Wind the inductors
see Appendix A
Sand the leads

6. Network analyzer
S22 - measures voltage reflection from 2nd port – terminating impedance
Port 1
Port 2
component
fixture

7. Calibration standards
Uncalibrated – measures all after the port
Calibration – brings reference to fixture port
Standards – open, short, 50Ω
After calibration – check Smith chart
component
fixture

8. Standards on Smith chart
Polar graph of Γ (S22)
Γ= 1, -1, 0 for O, S, L
Should look like dots
after calibration
(hardly visible)

9. Inductor Toroidal inductors exhibit parallel resonance
L from low frequency, C from resonance
R relates to Q – peak width

10. Quartz crystal Quartz between two plates – capacitor
Motion arm due to piezo effect
Example values:
At resonance – like high Q inductor
Rapid phase change – stable oscillations

11. Quartz crystal
Co – from low f

12. Quartz crystal
Shift in fp due to parallel cap

13. Important points Slow down the sweep to a few sec
Change trigger to single
Change IF BW to 500 Hz
Calibrate NA on 8 to 11 MHz
Number of points should be large
Reduce the range, remeasure