Module 8 - Oscillators LEARNING MATERIALS

Introduction

In this module, we will study microwave oscillators and their applications to microwave circuits. For this section, do any combination of assignments to receive 50 points.

Learning Materials

Material/Lecture content

Readings:
- Planar Microwave Circuits, by Lee chapter 15
- Microwave Engineering, by Pozar Ch 11_5.pdf and Pozar HW ch11.pdf
- RF and Microwave Communication Circuits by Misra ch12_7.pdf
- RF and Microwave Electronics Illustrated by Radmanesh ch17.pdf
- Zoya Popovic Oscillator lecture notes
- BJT Oscillators
Power Points from Class
- Negative Resistance oscillators 1.ppt
- Colpitts and Hartley Oscillators
  - oscillators 2 colpitts and Hartley.ppt
  - Gonzalez bias networks.pdf
  - colpitts.m
- oscillators 3 VCO.ppt

Types of Oscillators

Goal: Learn about the many types of oscillators

Readings:

(scan through types of oscillators) Planar Microwave Circuits, by Lee chapter 15
(scan through types of oscillators) Zoya Popovic Oscillator lecture notes

Additional resources:

RF and Microwave Electronics Illustrated by Radmanesh ch17.pdf
BJT Oscillators

Homework:

Module 8a Assignment-- Oscillator types (10points)

Two-port Negative Resistance Transistor Oscillators

Readings:

Read this section. We will be following Example 11.9 in class.
- Microwave Engineering, by Pozar Ch 11_5.pdf and Pozar HW ch11.pdf
This describes how S parameters can be converted between different transistor configurations:
- RF and Microwave Communication Circuits by Misra ch12_7.pdf
Here's another explanation of how to do the oscillator design:
- RF and Microwave Electronics Illustrated by Radmanesh ch17.pdf
This has several additional examples:
- Microwave Transistor Amplifiers by Gonzalez Gonzales ch5_3.pdf
Here's a deeper dive into the math, including the factor of 3 used in the ZL calculation:
- Jensen and Warnick http://ece464web.groups.et.byu.net/notes/ln44_58.pdf

In class materials:

We'll be working through example 11.9 in Pozar Ch 11_5.pdf

oscillators 1.ppt
oscillator.m
S-parameter files
- Ex11_9.s2p
- Ex11_9_Sprime.s2p

homework:

Module 8b Assignment-- Transistor Oscillator Design (30points)

Hartley and Colpitts Oscillators

Feedback Oscillator basics
- Video:The working principle of the oscillator explained

https://www.youtube.com/watch?v=XVS8Puf4tiw

- Readings:
  - RF and Microwave Communication Circuits by Misra chapter 12.1 (pp. 479-484) (Especially note the different locations the resonator can be placed in the generalized oscillator design.)
  - Barkhausen stability criterion (necessary but not sufficient criterion for oscillation)
LC Resonator basics
- Video: Colpitts Oscillator Explained

https://www.youtube.com/watch?v=1fgw-ONlAcc

- Reading: See several different LC configurations ( there are so many different ways to arrange the LC resonators)
  - section 17.5.1 (pp. 583-586) Radmanesh ch17.pdf
  - Gonzales ch5_5.pdf
  - Misra chapter 12_1.pdf
  - LudwigBretchko ch10_1.pdf
Colpitts Oscillator:
- Video (see above) and
  - Colpitts Oscillator Design

https://www.youtube.com/watch?v=BXcJxeEQo-M

- - Colpitts Oscillator BJT Circuit example

https://www.youtube.com/watch?v=z761q6rk-tw

- Readings:
  - Simple Colpitts Design https://www.petervis.com/Education/colpitts-oscillator/colpitts-oscillator-design.html
  - RF and Microwave Communication Circuits by Misra chapter 12.1 (pp. 484-489)
  - Planar Microwave Engineering by Lee, chapters 15.3.3 and 15.3.4
  - Colpitts with LC tank circuit
  - Colpitts another explanation
- Example in Class
Hartley Oscillator
- Video: Hartley Oscillator Circuit

https://www.youtube.com/watch?v=3B_sBX_11Zw

- Readings:
  - - Hartley oscillator with LC tank on the input side of the transistor amplifier

Homework:

Module 8c Assignment-- Hartley Oscillator Design (30points)

Voltage Controlled Oscillators (VCO)

Review: Varactor Diodes
- Video:

https://www.youtube.com/watch?v=icw8terKP-M

VCO Basics
- Video

https://www.youtube.com/watch?v=EeYL6lJsNT8

- Applications of VCOs
Resonant circuits with Varactor diodes
- See Figs 5-45, 5.54 and 5-55 in VCO Rhode Newkirk.pdf
- Design of Colpitts Oscillator with varactor VCO Ludwig Bretchko.pdf
- Design of negative resistance oscillator with varactor diode VCO Gonzalez.pdf

Supplementary Material

Several other VCO configurations
Details of several commercial VCO circuits, and more details on VCO parameters VCO Rhode Newkirk.pdf
Another look at Varactor tuned circuits VCO Radmanesh.pdf and VCO Misra.pdf

Supporting Material

ADS Support Materials
Review: Biasing a BJT amplifier https://www.electronics-tutorials.ws/amplifier/transistor-biasing.html
More on biasing Gonzalez bias networks.pdf
Some of these analyses use h-parameters , which can be derived from S-parameters.

Class LIVE VIDEO Meetings

We will meet Tuesday and Thursday, using the Zoom link on your left menu. If the meeting link doesn't show up, look under Previous Meetings.

Assignments

You can access the activities by clicking "next" below or through the navigation links at the top of the page. Choose 50 points from the Assignments below:

Module 8a Assignment-- Oscillator types (10points)

Module 8b Assignment-- Transistor Oscillator Design (30points)

Module 8c Assignment-- Hartley Oscillator Design (30points)

Module 8: Tutorial Assignment -- Oscillators (20 points)

Module 8 -- Oscillators Muddiest OR Most Interesting Point Discussion (10 pts)

Additional assignments will be posted soon.