Distributed Voltage Controlled Oscillator

Team Members:Dane Stivers Todd Beyer

Tim MacShane Monica Studnicki

Advisor:Dr. Prasad N. Shastry

Funded By:Electrical Engineering Dept..

Bradley University

Peoria, IL, 61625

Outline of Presentation

• Project Summary• Previous Work Done• Standards Applicable• Top Level Design• Functional Description• Division of Labor• Image of Tunable Bandpass Filter• Image of Distributed Amplifier• Specifications• Components List• Equipment List• Facilities Used• Software Used• Proposed Schedule

Project Summary

• Oscillators are one of the important components in communication systems. They establish transmitter carrier frequency, and drive frequency converters. There are several types of oscillators that are used in commercial and military systems. VCO’s that are tunable to one octave frequency range are available commercially.

• It is well known that a distributed amplifier provides very wide bandwidth and high gain. Our design of a VCO will incorporate the distributed amplifier in order to allow a tunable frequency of close to one decade frequency (limited by the transistors). This design approach has never been successfully implemented before.

Previous Work Done

• Patents Held:– None Found

• Masters Thesis Work:– Sunil Modur Nagabhushana

• Graduate Level Work:– Yongqiang He

Standards Applicable

• ISM frequency band:– Defined by FCC for general unregulated use:

• CFR 47 Part 2 -Frequency Allocations

• Standards and Procedures for Microstrip layout and Fabrication:– Variable based upon the fabrication facility

• Safety– General usage as per ISM band regulations

Top Level Design

Tunable Bandpass Filter

Amplifier

Power Divider

Distributed Amplifier

DC Bias

DC Bias

VCO Output

Tuning Voltage

Functional Description

Subsystem Inputs From Output To

Tunable BandpassFilter

Tuning VoltageAmplifier

Distributed Amplifier

Distributed Amplifier DC BiasBandpass Filter

Power Divider

Power Divider Distributed Amplifier AmplifierOverall System Output

Amplifier DC BiasPower Divider

Tunable Bandpass Filter

Division of Labor

Dane Stivers and

Monica Studnicki

• Distributed Amplifier

• Power Divider

Todd Beyer and

Tim MacShane

• Tunable Bandpass Filter

• Amplifier

Specifications

• Output Frequency Range: 1 to 3 GHz– Design to be tested by operation within the ISM (Industrial,

Scientific, Medical) band

• Output Power: Stable over whole frequency range

• Output Impedance 50• Tuning Voltage: 0 to 20 V

• Biasing Voltage: 15 V DC

Components List

(10 – 12) Discrete Transistors w/ a similar non-linear model as the NE76084S.

Power Divider (PS-2-4000F Wide Band Two Way Combiner/Divider). (20) Coilcraft 22nH Inductors (0603CS-22NX-BC). (8-12) Dielectric Laboratories 2400pF DC Blocking Capacitors. (4) Varactor Diode that has similar operating limits as the MA 46457-

186 (4) Broadband Amplifier (EIC-1019 Broadband Amplifier) (4) High Frequency Circuit Boards

RO3003 and TMM10i

(12-20) Microstrip Board to Coax Connectors (50 ) (5) Microstrip Box Mount Coax Connectors (50 ) Metal Casing for Final Design

Equipment List

Spectrum Analyzer Network Analyzer Soldering Iron Voltage Sources

Facilities Used

– The Prototype and Subsystems will be fabricated by us using the fabrication lab on campus.

– Bradley University’s machine shop will be utilized for the making if the metal box that the final design will go into.

– Also, the final design will be sent outside to a manufacturer (to be determined) to be professionally made.

Software Usage

HP ADS Mstrip MATCH CAMAD

Proposed Schedule

• Week 1:– Verify Receipt of Components– Continue Simulations

• Week 2:– Verify Components– Continue Simulations

• Week 3:– Complete Verification of Components– Start Construction of Subsystems

• Weeks 4-9:– Continued Construction of Subsystems– Test Subsystems– Test Interconnected Functionality

Proposed Schedule (Continued)

• Week 10:– Construct Prototype

• Week 11:– Test Prototype

• Weeks 12-14:– Trouble Shooting

– Preparation for Expo

– Preparation of Final Report