microwave technology - guceee.guc.edu.eg/courses/communications/comm903 microwave techn… ·...
TRANSCRIPT
GUC (Dr. Hany Hammad) 9/5/2016
COMM (903) Lecture # 1 1
© Dr. Hany Hammad, German University in Cairo
(COMM 903)
Microwave Technology
© Dr. Hany Hammad, German University in Cairo
Contents
• Introduction:
– Course contents.
– Assessment.
– References.
• Microwave Sources.
• Transistor Model Extraction.
• Signal flow graphs.
GUC (Dr. Hany Hammad) 9/5/2016
COMM (903) Lecture # 1 2
© Dr. Hany Hammad, German University in Cairo
Course Contents
• Active Microwave & RF Circuits Analysis & Design
– Noise, Microwave Sources, Amplifiers, Mixers & Oscillators.
• Metamaterials and Transmission Lines
– Basic properties, Transmission Line Implementations and Applications.
© Dr. Hany Hammad, German University in Cairo
Teaching Assistant (Tutorials)
Engs. Randa El Khosht
References
David M. Pozar, “Microwave Engineering”, 3rd Edition, Wiley. Lecture Notes
Eng. Yasmine Abdella
Teaching Assistant (Advanced Comm. Lab.)
GUC (Dr. Hany Hammad) 9/5/2016
COMM (903) Lecture # 1 3
© Dr. Hany Hammad, German University in Cairo
Assessment
Quizzes (2-3) 15
Tutorial Assignments 5
Project 10
Mid Term Examination 25
Final Examination 45
Total 100
© Dr. Hany Hammad, German University in Cairo
Microwave Sources
Low Power &
Low Frequencies
Sources
High Power &/or
high frequencies Sources
Solid State Sources Microwave Tubes
Microwave Engineering, 3rd Edition by David M. Pozar
Copyright © 2004 John Wiley & Sons
GUC (Dr. Hany Hammad) 9/5/2016
COMM (903) Lecture # 1 4
© Dr. Hany Hammad, German University in Cairo
Microwave Tubes
Types of Microwave Tubes:
– Klystron
– TWT (Traveling Wave Tubes)
• Helix TWT.
• Coupled cavity TWT.
– Magnetron.
– Gyroton.
– Gridded Tube.
– CFA (crossed field amplifiers)
© Dr. Hany Hammad, German University in Cairo
Solid State Sources
• Advantages:
– Small Size.
– Low Cost.
– Compatibility with microwave integrated circuits.
• Disadvantages:
– Low power.
– Low frequencies.
GUC (Dr. Hany Hammad) 9/5/2016
COMM (903) Lecture # 1 5
© Dr. Hany Hammad, German University in Cairo
Solid State Sources
• Can be categorized as:
– Two terminal devices
• Ex.: Diodes.
– Three terminal devices
• Ex.: Transistor oscillators.
© Dr. Hany Hammad, German University in Cairo
Diode Sources
• Most common diode sources:
– Gunn diode.
– IMPATT diode.
• Directly convert DC bias to RF power in the frequency range of 2 to 100 GHz.
GUC (Dr. Hany Hammad) 9/5/2016
COMM (903) Lecture # 1 6
© Dr. Hany Hammad, German University in Cairo
Gunn Diode
• Even though everyone uses this term! It’s more accurate name is a “Transferred Electron Device” (TED). Why isn't it a "real" diode? Because it only uses N-type semiconductor.
• Gunn diodes have been around since John Gunn discovered that bulk N-type GaAs can be made to have a negative resistance effect.
• Three regions exist: two of them are heavily N-doped on each terminal, with a thin layer of lightly doped material in between.
Broadband Microwave Amplifiers by Bal S. Virdee, Avtar S. Virdee, & Ben Y. Banyamin
Copyright © 2004 Artech House
© Dr. Hany Hammad, German University in Cairo
Gunn Diode
Two Gunn diode sources. The unit on the left is a mechanically tunable E-band source, while the
unit on the right is a varactor-tuned V-band source.
Microwave Engineering, 3rd Edition by David M. Pozar
Copyright © 2004 John Wiley & Sons
GUC (Dr. Hany Hammad) 9/5/2016
COMM (903) Lecture # 1 7
FET
© Dr. Hany Hammad, German University in Cairo
Small Signal Models
© Dr. Hany Hammad, German University in Cairo
GUC (Dr. Hany Hammad) 9/5/2016
COMM (903) Lecture # 1 8
© Dr. Hany Hammad, German University in Cairo
The GaAs MESFET Structure
Cross sectional view of the GaAs MESFET structure shows the depletion region below the gate
The contact of the gate is made of metal-semiconductor Schottky Contact rather than a metal-oxide-semiconductor (MOS) structure, which is used in the MOSFET device. This approach minimizes the device’s gate to source capacitance, which otherwise would degrade the high-frequency gain performance.
Broadband Microwave Amplifiers by Bal S. Virdee, Avtar S. Virdee, & Ben Y. Banyamin
Copyright © 2004 Artech House
© Dr. Hany Hammad, German University in Cairo
The GaAs MESFET
d
satsm
h
vwg
gm= intrinsic device transconductance hd= depletion-layer depth w = gate width s= semiconductor dielectric constant vsat= saturated carrier velocity
gs
mT
C
gf
2 fT = Unity-current-gain frequency
Cgs= gate to source capacitance
At frequencies above fT the current passing through the Cgs is greater than that produced by the transconductance, therefore, fT represents a
fundamental high-frequency limit.
d
gs
gsh
lwC
g
satT
l
vf
2
For optimum high-frequency performance, the device designer must either increase the saturated carrier velocity or decrease the gate length.
GUC (Dr. Hany Hammad) 9/5/2016
COMM (903) Lecture # 1 9
© Dr. Hany Hammad, German University in Cairo
Device Characterization and Modeling
• Small signal model Intrinsic & Extrinsic elements is determined using the hot and cold deembedded S-parameters measurements.
• Large Signal model is determined by using the semi-empirical method, and it uses the measured pulsed dc I-V data of the device and no assumptions are made relating to the physical operation of the device itself.
• One key issue in S-parameters measurements is the accurate calibration of the network analyzer. The calibration of the instrument should remove unwanted and repeatable information, such as the effects of non-ideal transmission lines, connectors, and circuit parasitic.
© Dr. Hany Hammad, German University in Cairo
Small-signal device modeling procedure
Cold Vds = 0 V Vgs = -3 V (pinch off)
Broadband Microwave Amplifiers by Bal S. Virdee, Avtar S. Virdee, & Ben Y. Banyamin
Copyright © 2004 Artech House
GUC (Dr. Hany Hammad) 9/5/2016
COMM (903) Lecture # 1 10
© Dr. Hany Hammad, German University in Cairo
Hot S-parameters Extraction
Cdc = diople layer capacitance
The extrinsic parameters Cgp, Cdp, Lg, Ld, Rg, Rs and Rd. The gate and drain bond-pad capacitance (Cpg and Cpd) in the modeling process.
Rg & Rd represent the device’s gate and drain resistance. Rs & Ls are the source resistance and inductance.
Broadband Microwave Amplifiers by Bal S. Virdee, Avtar S. Virdee, & Ben Y. Banyamin
Copyright © 2004 Artech House
© Dr. Hany Hammad, German University in Cairo
Cold S-parameters Extraction
Broadband Microwave Amplifiers by Bal S. Virdee, Avtar S. Virdee, & Ben Y. Banyamin
Copyright © 2004 Artech House
GUC (Dr. Hany Hammad) 9/5/2016
COMM (903) Lecture # 1 11
© Dr. Hany Hammad, German University in Cairo
Cold S-parameters Extraction
absgsgc CLLjRRZ 111
bsscc CLjRZZ 12112
bcsdsdc CLLjRRZ 122
111 baab CCC 111 cbbc CCC
1211Re ccg ZZR
12Re cs ZR
1222Re ccd ZZR
absgc CLLZ 1Im 2
11
bsc CLZ 1Im 2
12
bcsdc CLLZ 1Im 2
22
© Dr. Hany Hammad, German University in Cairo
Hot S-parameters Extraction
gsi
gdCjR
CjY
1
111
gdCjY 12
gdgsi
j
mo CjCRjegY 121
gdds
ds
CCjR
Y 1
22
Broadband Microwave Amplifiers by Bal S. Virdee, Avtar S. Virdee, & Ben Y. Banyamin
Copyright © 2004 Artech House
gsv+
-
j
mom egg
GUC (Dr. Hany Hammad) 9/5/2016
COMM (903) Lecture # 1 12
© Dr. Hany Hammad, German University in Cairo
Model Extraction
12Im YCgd
2
11
2
1111
Im
Re1
Im
gd
gd
gsCY
YCYC
2
11
2
1111 ReImRe YCYYR gdi
2222
11
2
21 1)Im(Re igsgdmo RCCYYg
moigsgd gRCYYC 2121
1 ReImsin/1
gdds CYC 22Im
22Re1 YRds
j
mm eggo
© Dr. Hany Hammad, German University in Cairo
S-parameters files
GUC (Dr. Hany Hammad) 9/5/2016
COMM (903) Lecture # 1 13
© Dr. Hany Hammad, German University in Cairo
Extraction Steps
• Measure the S-parameters and save as .s2p file.
• Load file into Matlab (load file name.s2p)
• Convert the s2p to y-parameters using the equations (or using s2y command in matlab.
dsR dsCgsmvg
iR
gdC
gsC
Gate Drain
Source
+
-
gsv
I1 I2
V1 V2
2121111 VYVYI
2221212 VYVYI
MESFET Model Extraction Project
GUC (Dr. Hany Hammad) 9/5/2016
COMM (903) Lecture # 1 14
In case of V2=0
dsR dsCgsmvg
iR
gdC
gsC
Gate Drain
Source
+
-
gsv
I1 I2
V1 V2=0
gsmvg
iR
gdC
gsC
Gate
Source
+
-
gsv
I1 I2
V1 V2=0
Drain
Finding Y11 & Y21
gsmgd vgCjVI 12
igsgsi
gs
gsRCj
V
CjR
CjVv
11
111
igs
mgd
RCj
VgCjVI
1
112
gd
igs
m
V
CjRCj
g
V
IY
1
01
221
2
gsi
gd
VCjR
CjV
IY
1
1
01
111
2
gsmvg
iR
gsC
Gate
Source
+
-
gsv
I1 I2
V1 V2=0
gdCjV 1
Finding Y11 & Y21
GUC (Dr. Hany Hammad) 9/5/2016
COMM (903) Lecture # 1 15
igs
igs
igs
gs
gd
igs
gs
gdRCj
RCj
RCj
CjCj
RCj
CjCjY
1
1
1111
222
22
111 igs
igsgs
gdRC
RCCjCjY
2221 igsRCD
gd
gsigsC
D
Cj
D
RCY
22
11
Finding Y11 & Y21
dsR dsCgsmvg
iR
gdC
gsC
Gate Drain
Source
+
- gsv
I1 I2
V1
V2
dsR dsC
gdCGate
Drain
Source
I1 I2
V1
V2 gdds
dsV
CCjRV
IY
1
02
222
1
gd
V
CjV
IY
02
112
1
Finding Y11 & Y21
GUC (Dr. Hany Hammad) 9/5/2016
COMM (903) Lecture # 1 16
pFFCgd 02548.0102548.2 14
pFFCgs 11782.0101782.1 13
3838.7iR
Sgm 0664.0
sec35229.0sec105229.3 13 p
pFFCds 47753.0107753.4 14
924.198dsR
Extracted Model Parameters
NE321000 Vds = 2 V Id = 10 mA
0 5 10 15 20 25 30-0.5
0
0.5
1
1.5
2
2.5
3
3.5
4x 10
-3
freq. (GHz)
e(Y
11)
(S)
Measured
Calculated
0 5 10 15 20 25 300
0.005
0.01
0.015
0.02
0.025
0.03
freq. (GHz)
m
(Y11)
(S)
Measured
Calculated
Results Y11 (Measured Vs Calculated from extracted Model)
GUC (Dr. Hany Hammad) 9/5/2016
COMM (903) Lecture # 1 17
0 5 10 15 20 25 30-3
-2.5
-2
-1.5
-1
-0.5
0
0.5x 10
-4
freq. (GHz)
e(Y
12)
(S)
Measured
Calculated
0 5 10 15 20 25 30-5
-4.5
-4
-3.5
-3
-2.5
-2
-1.5
-1
-0.5
0x 10
-3
freq. (GHz)
m
(Y12)
(S)
Measured
Calculated
Results Y12 (Measured Vs Calculated from extracted Model)
0 5 10 15 20 25 300.058
0.06
0.062
0.064
0.066
0.068
0.07
0.072
0.074
freq. (GHz)
e(Y
21)
(S)
Measured
Calculated
0 5 10 15 20 25 30-0.025
-0.02
-0.015
-0.01
-0.005
0
freq. (GHz)
m
(Y21)
(S)
Measured
Calculated
Results Y21 (Measured Vs Calculated from extracted Model)
GUC (Dr. Hany Hammad) 9/5/2016
COMM (903) Lecture # 1 18
0 5 10 15 20 25 304.7
4.8
4.9
5
5.1
5.2
5.3x 10
-3
freq. (GHz)
(Y
22)
(S)
Measured
Calculated
0 5 10 15 20 25 300
0.002
0.004
0.006
0.008
0.01
0.012
0.014
freq. (GHz)
m
(Y22)
(S)
Measured
Calculated
Results Y22 (Measured Vs Calculated from extracted Model)