GUC (Dr. Hany Hammad)
1/24/2016
Radio Frequency Engineering Associate Prof. Hany Hammad
Lecture #1 Contents • Introduction. • What is Radio Frequency Engineering?. • Course Contents. • Introduction to RF and microwave engineering. • Printed transmission lines.
© Dr. Hany Hammad, German University in Cairo
COMM (603) Lecture #1
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GUC (Dr. Hany Hammad)
1/24/2016
Introduction • Course Title: – Radio Frequency Engineering. (COMM 603) • Instructors: – Assoc. Prof. Dr. Hany Hammad. – Eng. Randa • Course Type: – Requirement for IET Communications and Electronics students.
• Course Schedule: – 1 lecture per week. – 1 tutorial per week.
© Dr. Hany Hammad, German University in Cairo
Course Contents • • • • • • • •
Introduction to RF Technologies Microwave Network Analysis Transmission Lines Power dividers and directional couplers Impedance Matching and Tuning Microwave Resonators Lumped elements RF Filters
© Dr. Hany Hammad, German University in Cairo
COMM (603) Lecture #1
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GUC (Dr. Hany Hammad)
1/24/2016
Communications System block diagram Antenna UpConverter Modulating Signal-Information
Transmitter
Band Pass Filter (BPF)
Modulator
Local Oscillator
Power Amplifier
LO Transmission Medium (Communication Engineering)
Demodulated SignalInformation (low frequency)
Demodulator
Low Noise Amp.
BPF/IF Amp.
Receiver
Band Pass Filter (BPF)
LO
© Dr. Hany Hammad, German University in Cairo
Evolution of RF applications
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COMM (603) Lecture #1
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GUC (Dr. Hany Hammad)
1/24/2016
RF for Smart Homes
© Dr. Hany Hammad, German University in Cairo
RFID System
© Dr. Hany Hammad, German University in Cairo
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GUC (Dr. Hany Hammad)
1/24/2016
RFID System
© Dr. Hany Hammad, German University in Cairo
RF Filters
© Dr. Hany Hammad, German University in Cairo
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GUC (Dr. Hany Hammad)
1/24/2016
Dividers & Combiners
© Dr. Hany Hammad, German University in Cairo
Couplers & Hybrids
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COMM (603) Lecture #1
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GUC (Dr. Hany Hammad)
1/24/2016
Microwave amplifier
© Dr. Hany Hammad, German University in Cairo
Planar Transmission Lines • Microstrip. • Slot Line. • Coplanar waveguide. • Coplanar lines.
© Dr. Hany Hammad, German University in Cairo
COMM (603) Lecture #1
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GUC (Dr. Hany Hammad)
1/24/2016
Advantages of Using planar TLs • They are planar (A planar configuration implies that the characteristics of the element can be determined by the dimensions in a single plane). • They can be fabricated by photolithographic and photo etching processes. • Easily integrated with other passive and active devices.
© Dr. Hany Hammad, German University in Cairo
Type of planar transmission lines
Microstrip Line
Parallel Strips Line
Coplanar Waveguide
Slot Line
Conductor Dielectric
Coplanar Strips © Dr. Hany Hammad, German University in Cairo
COMM (603) Lecture #1
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GUC (Dr. Hany Hammad)
1/24/2016
Microstrip Transmission Lines
Dielectric (substrate)
Conductor (Signal)
Conductor (ground)
H-Fields E-Fields
© Dr. Hany Hammad, German University in Cairo
Microstrip Transmission Lines
H-Fields E-Fields
© Dr. Hany Hammad, German University in Cairo
COMM (603) Lecture #1
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GUC (Dr. Hany Hammad)
1/24/2016
Microstrip Transmission Lines Microstrip Width
Microstrip Thickness
Substrate Thickness
d
Substrate Dielectric Constant
© Dr. Hany Hammad, German University in Cairo
Microstrip Transmission Lines Other configurations for microstrip TL
© Dr. Hany Hammad, German University in Cairo
COMM (603) Lecture #1
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GUC (Dr. Hany Hammad)
1/24/2016
Microstrip Transmission Lines Effective Dielectric constant (eff)
r 1
r r
r eff 1 eff r
eff
Is function of the dielectric constant, width W, and thickness (d)
c
vp
ko eff
eff
© Dr. Hany Hammad, German University in Cairo
Formulas for Microstrip transmission lines Given W, d, r Find Zo & eff
Given Zo, r & d Find W
eff e
r 1 r 1 2
2
1
d W 60 8d W ln e W 4d 120 Zo W W e 1.393 0.667 ln 1.444 d d 1 12
W 1 d W 1 d
8e A 2A W e 2 d 2 B 1 ln( 2 B 1) r 1 ln( B 1) 0.39 0.61 2 r r
A
Zo r 1 r 1 0.11 0.23 60 2 r 1 r
B
W 2 d W 2 d
377 2Z o r
© Dr. Hany Hammad, German University in Cairo
COMM (603) Lecture #1
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GUC (Dr. Hany Hammad)
1/24/2016
Example Calculate the width and length of a microstrip line for a 50 characteristic impedance and a 90o phase shift at 2.5 GHz. The substrate thickness is d=0.127 cm, with r=2.20. Answer
A
(50) (2.2) 1 (2.2) 1 0.11 0.23 1.1591 60 2 (2.2) 1 (2.2)
2
W 3.126 d 3.051
e
d 0.127cm
2
377 7.985 2(50) (2.2)
W 0.387cm
2.2 1 2.2 1 1 1.87 2 2 1 12(0.328) l
l e
l e kol v c 2 2.5 109 1.87 l 8 3 10 2 2
B
l 0.0219 m 2.19 cm
© Dr. Hany Hammad, German University in Cairo
Losses in Microstrip Lines • Two types of losses: – Dielectric losses.
d
ko r ( e 1) tan Np/m 2 e ( r 1)
– Conductor losses.
c
Rs
Rs Np/m Z oW
o 2
Surface resistivity
© Dr. Hany Hammad, German University in Cairo
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GUC (Dr. Hany Hammad)
1/24/2016
Conductivities of Some Materials
© Dr. Hany Hammad, German University in Cairo
Dielectric constants & loss tangents of some materials
© Dr. Hany Hammad, German University in Cairo
COMM (603) Lecture #1
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GUC (Dr. Hany Hammad)
1/24/2016
Losses in Microstrip Lines
© Dr. Hany Hammad, German University in Cairo
Dielectric constants & loss tangents of some materials • Commercial Materials come in standard dielectric constants and thicknesses. • For example: – Rogers Corporation provide RT/Duroids. (http://www.rogerscorporation.com/). – Coors Technology (http://www.coorstek.com/)
© Dr. Hany Hammad, German University in Cairo
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GUC (Dr. Hany Hammad)
1/24/2016
Power Handling Capability • Power handling capability of a microstrip is limited by: – Heating caused because of Ohmic and dielectric losses • Limits the average power of the microstrip line. – Dielectric breakdown. • Limits the peak power.
© Dr. Hany Hammad, German University in Cairo
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