ECE 145B / 218B, notes set 10: Oscillators, Part 2.€¦ · Oscillators, Part 2. Mark Rodwell...

class notes, M. Rodwell, copyrighted 2012

ECE 145B / 218B, notes set 10: Oscillators, Part 2.

Mark Rodwell

University of California, Santa Barbara

[email protected] 805-893-3244, 805-893-3262 fax


Two-Port Oscillator Theory

s.answer thi y willport theor-Two

? wellsoscillatorour desigingnot weareOr

?oxymoron an n"oscillatio offrequency maximum" Is

!at oscillatenot willsoscillator standardMany

topology?particular apick reason toany thereIs

hoc.-ad seems topology oscillator ofSelection

?Why

maxf



port.-2 passive a

ith feedback w add ..and

etc) r,(transisto

port-2 activean Take

lossless beclearly shouldport -2 passive The

soscillator transistor-1 possible all analyzing are We

general. completely isfeedback The



reciprocalnot possibly ; :network Active

.reciprocal is this; :network Passive

,

,

ija

ijp

Y

Y

etc.

emitter,-common tobase-common

from oscillator s transformThis

3.or 2, 1, nodesat placed becan

connection ground that theNote


The feedback network

.equivalent arebut

used, becan networkscomplex More

network Delta a as

known also isnetwork Pi The

network. Pi aor T a

either of composed becan It

.or either by drepresente

becan network feedback The

,, ijpijp ZY

imaginary.purely are sadmittance

and impedancesfeedback that theNote


The feedback network

12,22,

12,11,

12,

,

12,22,

12,11,

12,

,

ppo

ppi

pf

fof

ffi

pij

ppo

ppi

pf

fof

ffi

pij

ZZZ

ZZZ

ZZ

ZZZ

ZZZZ

YYY

YYY

YY

YYY

YYYY

imaginary.purely are sadmittance

and impedancesfeedback that theNote


Series-Line-Tuned Oscillator


Shunt-Line-Tuned Oscillator


The Oscillator

2222,21,21,

12,12,1111,

,

22,21,

12,11,

22,22,21,21,

12,12,11,11,

,

22,22,21,21,

12,12,11,11,

,

as this write:Simplify

Oscillator

device Active

jBGjBjBG

jBjBGjBGY

YY

YY

jBjBjBGjBjBG

jBjBGjBjBjBGY

jBGjBG

jBGjBGY

afaa

faaa

ijosc

oscosc

oscosc

foaafaa

faafiaa

ijosc

aaaa

aaaa

ija

desire. weany value to

and , ,

set can wenetwork,

feedback theadjustingBy

2211 fBBB


Oscillator Input Admittance

2222,21,21,

12,12,1111,

,,

22,21,12,11,

122,21,22

2

1

22,21,

12,11,

2

1

)/(

)/( 0

jBGjBjBG

jBjBGjBGYY

YYYYY

VYYVI

V

V

YY

YY

I

I

afaa

faaa

ijoscijosc

oscoscoscoscin

oscosc

oscosc

oscosc

inin

a

faafaa

ain jBGjBG

jBjBGjBjBGjBGY

2222,

21,21,12,12,

1111,

possible. as negative as make toand , 0 want We inin GB


Input Conductance

2

22

2

22,

2221,12,12,21,

2

22

2

22,

22,21,12,21,12,

11,

)()(

))((

BG

BBBGBBG

BG

GBBBBGGGG

a

faafaa

a

afafaaa

ain

2

22

2

22,

2221,12,21,12,22,21,12,12,21,

11

2

22

2

22,

2221,12,12,21,22,21,12,21,12,

11,

2

22

2

22,

2222,21,12,12,21,21,12,21,12,

1111,

2222,

21,21,12,12,

1111,

))(()()(

)()())((

)()())((

)()(

BG

BBBBBGGGBBGBBGBB

BG

BBBGBBGGBBBBGGGG

BG

jBGBBGBBGjBBBBGGjBGY

jBG

BBjGBBjGjBGY

a

fafaaaafaafaa

in

a

faafaaafafaaa

ain

a

afaafaafafaaa

ain

a

faafaa

ain

slides.next on theshown is This

e.conductancinput negative themaximize omanually t tunedbe alsocan and

.* thesederive toablebeen veI' ely,Unfortunat

. negative large aobtain toand and pick should We

22

22

BB

GBB

f

inf

1958. June 139,-133 pp. 5,-CT Vol. Theory,Circuit on nsTransactio IRE

Networks" ActivePort -Twoin y Instabilit" Boothroyd, R. A. Page, D.F.

in given elementsfeedback Optimum*


Design Example (1): Topology, Negative G Tuning.

HBT GHz 800~with

Colpitts Base-Common GHz 620

maxf

loading. its removing buffer, disconnect tolargeset initially

collectorsr transisto toconnectedport Test

:collectors at the econductanc

negative maximum produce to tunedare and 21 CC


Design Example (2): Resonator Admittance

. zerofor tuned

been has inductanceresonator The

. negative maximum

for been tuned have and

.collectors at the

observed admittancePort

11

11

21

B

G

CC


Design Example (3): Connection of Buffer connected. isbuffer small; now is L

core. oscillator

on buffer of loading reduces

ratiodown -stepinductor 1:3

tuned-re bemust elementsfeedback The


Design Example (4): Negative G given Buffer

loading.output the

by suppressedsomewhat

been has econductanc

negative that theNote


Design Example (5): Transient Simulation

simulated. is

circuit theandresonator

theinto injected is pulse

current A)10(~ small a

:simulationTransient


Design Example (5): Transient Simulation

ps. 90at starts

axis time that theNote

here.shown not is

noscillatio of up-Build

simulation

loadline TransistorCI

CEV


2nd Example : Common-Collector Colpitts

buffer.output base-common with Colpittscollector -Common

bufferoutput base

-commonby oscillator of

loading reducesCapacitor

networkfeedback

inductorresonator


2nd Example : Common-Collector Colpitts

admittancePort SimulationTransient


3nd Example : The Real Design

layout GHz 300


3nd Example : The Real Design

ECE 145B / 218B, notes set 10: Oscillators, Part 2.€¦ · Oscillators, Part 2. Mark Rodwell...

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Transcript of ECE 145B / 218B, notes set 10: Oscillators, Part 2.€¦ · Oscillators, Part 2. Mark Rodwell...