EE542 Microwave Engineering - KAISTma.kaist.ac.kr/lecturenote/2014_Fall/1_Course overview.pdf · 7...

$: EE542 Microwave Engineering - KAISTma.kaist.ac.kr/lecturenote/2014_Fall/1_Course overview.pdf · 7 S.-O. Park, KAIST 7 The index of refraction (first graph) and absorption coefficient$
S.-O. Park, KAIST 1 EE542 Microwave Engineering,

Lecture Times: Tue. 14:30~15:45/ Thu. 14:30~15:45

Location: E3-2 Building, #2220

Professor: Seong-Ook Park, Ph. D. Tel: 350-7414, E-mail: [email protected]

Office Hours: E3-2 Building, #6-5206, Wed: 11:00AM~12:00 or by appointment

Course Objectives:

The goal of this course is to introduce students to the concepts and principles of the advanced

microwave engineering, including the use of computer aided design(CAD) methods.

RF/microwave CAD is employed extensively in industry and a knowledge of the principles and

methods used is important for anyone who may work in an RF/microwave related field. Theory

and design of passive and active microwave components, and microwave circuits including:

microstrip line, guided wave device, filter, amplifier, oscillators, and experimental

characterization of above components using the network analyzer, power and noise meters,

microwave theory and properties of ferrimagnetic material.

The general flow of this class is Application --> System --> Component; individual

components are analyzed by Fields --> Modes --> Equivalent Network.

Computer Usage:

Computer aides design tools, such as ADS, are used to design, analyze, and

construct RF and Microwave Circuits and Matlab

EE542 Microwave Engineering 2014 Fall Semester

Park, 2014 Fall, KAIST

S.-O. Park, KAIST 2

Welcome –

Instructor: Prof. Seong-Ook Park

Office: E3-2 Building, #6-5206

Email: [email protected]

Phone: 350-7414 (010-3412-1451)

Office hours – 11:00 AM ~ 12:00 (Wed.)

or by appointment

Assistant: Byung Kwan Kim, (010-3055-3536)

Email: [email protected]

Formulate good questions and seek the

answers.

EE542 Microwave Engineering, Park, 2014 Fall, KAIST

S.-O. Park, KAIST 3

Graduate Course webpage:

http://ma.kaist.ac.kr/lecturenote/2014_Fall/

Text: Lecture Note & Paper

Tentative grading distribution

Mid-Term Exam 35 %

Term-Proj 35 %

Homework 25%

Attendance 5%

Total 100 %

EE542 Microwave Engineering, Park, 2013 Fall, KAIST Park, 2014 Fall, KAIST

http://ma.kaist.ac.kr/lecturenote/2014_Fall/

S.-O. Park, KAIST 4

Maxwell Equation for Waves

Maxwell’s Equations for fields in free space are given by

E :Electric Field intensity (volt/meter)

H : Magnetic Field intensity (amperes/meter

D :Electric Flux density (coulombs/meter2)

B : Magnetic Flux density (webers/meter2)

(Constitutive Parameters and Relationships)

We recall that D=eE, B=mH, and J=sE + Jf´, where s is conductivity and Jf´is the free current density arising from sources other than conductivity. Assuming that there are no external free charge and currents in the region of interest, that is, we can take J = 0, r = 0 and Jf´=0.

0

0

HE

t

EH J

t

B

E

m

e

r

e

=

=

=

=

EE542 Microwave Engineering, Park, 2013. Fall, KAIST Park, 2014 Fall, KAIST

S.-O. Park, KAIST 5

Hertz's Parabolic Transmitting and

Receiving Structures (Antennas)

More Detailed Schematic

of Hertz's Experiment

In the 1880s many were seeking experimental evidence to establish

the equivalence of light and electromagnetic propagation. James

Clerk Maxwell's mathematical theory of 1873 had predicted that

electromagnetic disturbances should propagate through space at the

speed of light and should exhibit the wave-like characteristics of

light propagation.

Heinrich Hertz's Wireless Experiment (1887)

S.-O. Park, KAIST 6

The Electromagnetic Spectrum


S.-O. Park, KAIST 7

7

The index of refraction (first graph)

and absorption coefficient (second

graph) of liquid water as a function

of linear frequency. From J. D.

Jackson, Classical Electrodynamics

(2nd edition), John Wiley & Sons,

Inc., New York (1975).

The absorption coefficient falls precipitously over

7.5 decades to a value of a 3 10 -3 cm-1 in a

narrow frequency range between 4 1014Hz and 8

1014Hz.

This is a dramatic absorption window in what what

we call the visible region. The extreme transparency

of water here has it’s origins in the basic energy

level structure of the atoms and molecules.

The student may meditate on the fundamental

question of biological evolution on this water soaked

planet, or why animal eyes see the spectrum from

red to violate and of why the grass is green. Mother

nature has certainly exploited her window!

Park, 2014 Fall, KAIST EE542 Microwave Engineering,

S.-O. Park, KAIST 8

Lightwave Analogy to RF Energy

RF

Incident

Reflected

Transmitted

Lightwave

One of the fundamental concepts of RF power transmission involves incident, reflected and transmitted

waves traveling along transmission lines. It is helpful to think of traveling waves along a transmission line in

terms of a lightwave analogy. We can imagine incident light striking some optical component like a clear lens.

Some of the light is reflected off the surface of the lens, but most of the light continues on through the lens. If

the lens were made of some lossy material, then some of the light could be absorbed within the lens. If the

lens had mirrored surfaces, then most of the light would be reflected and little or none would be transmitted.

This concept is valid for RF signals as well, except the electromagnetic energy is in the RF range instead of

the optical range, and our components and circuits are electrical devices and networks instead of lenses and

mirrors.


S.-O. Park, KAIST 9

High-Frequency Device Characterization

Reflected

Incident

REFLECTION

SWR

S-Parameters S11,S22 Reflection

Coefficient

Impedance,

Admittance

R+jX,

G+jB

Return Loss

G, r

A

R =

Transmitted

Incident

TRANSMISSION

Gain / Loss

S-Parameters

S21,S12

Group

Delay

Transmission

Coefficient

Insertion

Phase

T,t

B

R =

R

A

Incident

Reflected

B

Transmitted DUT

Now that we fully understand the nature of electromagnetic waves, we must also recognize the terms used to describe them.

Common network analyzer terminology has the incident wave measured with the R (for reference) channel, while the reflected

wave is measured with the A channel and the transmitted wave is measured with the B channel. With amplitude and phase

information of these three waves, we can quantify the reflection and transmission characteristics of our device under test

(DUT). Some of the common measured terms are scalar in nature (the phase part is ignored or not measured), while others

are vector (both magnitude and phase are measured). For example, return loss is a scalar measurement of reflection, while

impedance is a vector (complex) reflection measurement. Ratioed reflection is often shown as A/R and ratioed transmission is

often shown as B/R, relating to the measurement channels used in the network analyzer.


S.-O. Park, KAIST 10

Gamma ray X Ray Visible

The Electromagnetic Spectrum

Audio

3KHz 3000GHz 108GHz 1010GHz 1012GHz

VHF HF MF LF VLF SEHF EHF SHF UHF

3 30 300KHz 3 30 300MHz 3 30 300GHz 3000GHz

100 10 1Km 100 10 1m 10 1cm 1mm 0.1mm

Frequency

Wavelength

AM broadcast band

Shortwave radio

FM broadcast band

VHF TV (2-4)

VHF TV (5-6)

VHF TV (7-13)

UHF TV (14-83)

Microwave ovens

335-1605 kHz

3-30 MHz

88-108 MHz

54-72 MHz

76-88 MHz

174-216 MHz

470-890 MHz

2.45 GHz

L-band

S-band

C-band

X-band

Ku-band

K-band

Ka-band

U-band

1-2 GHz

2-4 GHz

4-8 GHz

8-12 GHz

12-18 GHz

18-26 GHz

26-40 GHz

40-60 GHz



Fly’s-eye view. (Adult eye shown here.)

Medium 1

Medium 2

Sub-wavelength Device in Optics and Microwave

<1.6mm

0.5mm

Visible Light: 0.4mm~0.8mm



Sub-wavelength Structured Surfaces

(SWS) on crystal silicon

Sub-wavelength Device in Optics and Microwave

350nm

Visible Light: 400nm ~ 800nm The grating period is 150nm and

the groove is 350nm deep.

150nm

The reflectivity of the SWS surface is less than

3% at the wavelength from 200nm to 800nm.

At 400nm, Ref. decrease from 54.7% to 0.5%.



Manufacturing Photonic Materials: The Biological Option

As yet, technology has not caught up with our desire to create fully three dimensional, micron scale,

periodic structures. Drawing patterns on a surface presents few problems to the integrated circuit industry,

but that third dimension defeats us for the time being; though not, we suspect, for long.

On the other hand nearly all of biology is `engineered' on the

micron scale and with the help of DNA very complex structures

are manufactured. Not surprisingly the optical properties are

frequently exploited, nowhere with more spectacular effect than in

the butterfly. Many species show irridescent green or blue

patches and these owe their colouring to diffraction from periodic

material in the scales of the wing. On the left is an electron

micrograph of a broken scale taken from mitoura grynea

revealing a periodic array of holes responsible for the colour.

Right we see a specimen of the Adonis Blue

butterfly. Note the blue patches to the rear

of the wing.


S.-O. Park, KAIST 14 ICE649 Microwave Engineering,

Band Structures, Transmission and Reflection Coefficients

The figures show the band structure, transmission and

reflection coefficients for the logpile structure which

we have calculated using the OPAL codes. Compare

the band structure and transmission coefficient. Within

the band gap, where there are no extended states,

transmission falls dramatically whereas the

corresponding reflectivity reaches a peak.

Compare also the band structure shown

here to the dispersion surface on the

opposite page. Whereas the band

structure is an w, k plot, the dispersion

surface is a surface of allowed states in k

space at a fixed w. The band structure is

built by slicing through through

dispersion surfaces at different w.

Inverse opal structure can inhibit transmission of

specific wavelength of light



Transmission Parameters V Incident

Transmission Coefficient = T =

V Transmitted

V Incident

= t

DUT

Gain (dB) = 20 Log V

Trans

V Inc

= 20 log t

Insertion Phase (deg) = V

Trans

V Inc

=

Transmission coefficient T is defined as the transmitted voltage divided by the incident voltage. If

|Vtrans| > |Vinc|, we have gain, and if |Vtrans| < |Vinc|, we have attenuation or insertion loss. When

insertion loss is expressed in dB, a negative sign is added in the definition so that the loss value is

expressed as a positive number. The phase portion of the transmission coefficient is called insertion

phase.

Looking at insertion phase directly is usually not very useful. This is because the phase has a large

negative slope with respect to frequency due to the electrical length of the device (the longer the device,

the greater the slope). Often, the electrical delay feature of the network analyzer is used to remove the

linear portion of the phase response. This has the effect of removing the electrical length of the DUT,

resulting in a high-resolution display showing any deviations from linear phase.

Insertion Loss (dB) = - 20 Log V

Trans

V Inc

= - 20 log t

V Transmitted



Characterizing Unknown Devices

Using parameters (H, Y, Z, S) to characterize devices: gives us a linear behavioral model of our device

measure parameters (e.g. voltage and current) versus frequency under various source and

load conditions (e.g. short and open circuits)

compute device parameters from measured data

now we can predict circuit performance under any source and load conditions

H-parameters V1 = h11I1 + h12V2

I2 = h21I1 + h22V2

h11 = V1

I1 V2=0

h12 = V1

V2 I1=0

(requires short circuit)

(requires open circuit)

must make measurements under various conditions and compute a set of

parameters. These parameters can be used to completely describe the electrical

behavior of our device (or network), even under source and load conditions other

than when we made our measurements. For low-frequency characterization of

devices, the three most commonly measured parameters are the H, Y and Z-

parameters. All of these parameters require measuring the total voltage or current

as a function of frequency at the input or output nodes (ports) of the device.

Furthermore, we have to apply either open or short circuits as part of the

measurement. Extending measurements of these parameters to high frequencies is

not very practical.



Why Use S-Parameters?

relatively easy to obtain at high frequencies

measure voltage traveling waves with a vector

network analyzer

don't need shorts/opens which can cause active

devices to oscillate or self-destruct

relate to familiar measurement (gain,

loss, reflection coefficient ...)

can cascade S-parameters of multiple

devices to predict system performance

can compute H, Y, or Z parameters

from S-parameters if desired

can easily import and use S-parameter files in our

electronic-simulation tools

Incident Transmitted S 21

S 11 Reflected S 22

Reflected

Transmitted Incident

b 1

a 1 b 2

a 2 S 12

DUT

b 1 = S 11 a 1 + S 12 a 2

b 2 = S 21 a 1 + S 22 a 2

Port 1 Port 2



Measuring S-Parameters

S 11 = Reflected

Incident =

b 1

a 1 a 2 = 0

S 21 = Transmitted

Incident =

b 2

a 1 a 2 = 0

S 22 = Reflected

Incident =

b 2

a 2 a 1 = 0

S 12 = Transmitted

Incident =

b 1

a 2 a 1 = 0


S 11

Reflected b 1

a 1

b 2

Z 0

Load

a 2 = 0

DUT Forward

1


S 22

Reflected

b 2

a 2

b

a 1 = 0

DUT Z 0

Load Reverse



Equating S-Parameters with Common Measurement

Terms

S11 = forward reflection coefficient (input match)

S22 = reverse reflection coefficient (output match)

S21 = forward transmission coefficient (gain or loss)

S12 = reverse transmission coefficient (isolation)

Remember, S-parameters are inherently linear quantities -- however,

we often express them in a log-magnitude format

S-parameters are essentially the same parameters as some of the terms we have

mentioned before, as described above. Remember, S-parameters are inherently linear

quantities -- however, we often express them in a log-magnitude format. S11 and S22 are

often displayed on a Smith chart.



Early Days of Radar Chain Home Radar, Deployment Began 1936

Dover

Radar Site


Frequency : 20-30 MHz

• Wavelength

10-15 m

• Antenna

- Dipole Array on Transmit

- Crossed Dipoles on Receive

• Azimuth Beamwidth

- about 100 degree

• Peak Power

- 350 kW

• Detection Range

~160 nmi on

German Bomber

Chain Home Radar Antenna System


What Means are Available for Lifting the Fog of War ?


Surveillance and Fire Control Radars and Antenna System


Sources of Noise Received by Antenna

S.-O. Park, KAIST 25 < 01 / 20 >

Courtesy Lincoln Laboratory.

Courtesy of US Air Force.

Northrop GrummaNorthropGrumman

Courtesy of US Navy.




Airborne and Air Traffic Control Radars

S.-O. Park, KAIST 26 < 01 / 20 >

Instrumentation Radars & Antenna System


SPY-1

4100

elements

Large Phased Arrays Antenna System

THAAD Radar

25,344 elements

Courtesy of Raytheon.

Used with permission. Cobra Dane

15.3K active elements


Synthetic Aperture Radar

Synthetic aperture radar technology has provided terrain structural information to geologists for mineral

exploration, oil spill boundaries on water to environmentalists, sea state and ice hazard maps to navigators,

and reconnaissance and targeting information to military operations. There are many other applications or

potential applications. Some of these, particularly civilian, have not yet been adequately explored because

lower cost electronics are just beginning to make SAR technology economical for smaller scale uses.

Interferometry (3-D SAR).

Aa a part of the Airborne Multisensor Pod System

(AMPS) program, Sandia operates and maintains

the SAR pod. The SAR operates in the Ku-band

and is capable of 1 meter resolution. The pod is

visible under the right wing (near the fuselage) of

the aircraft.


This radar image is of an area thought to contain the ruins of the ancient settlement of Niya. It is located in the southwestern corner of the Taklamakan Desert in China's Sinjiang Province. This oasis was part of the famous Silk Road, an ancient trade route from one of China's earliest capitols, Xian, to the West.

Spaceborne Imaging Radar-C and X-band

Synthetic Aperture Radar (SIR-C/X-SAR)


KA-BAND AIR FORCE HISTORIC

HELICOPTER AND

PLANE STATIC DISPLAY LINE 4-INCH

RESOLUTION

Fine resolution Ka-band SAR images:


KA-BAND C-130s ON FLIGHT LINE 4-INCH RESOLUTION

fine resolution Ka-band SAR images:


Sandia solar collection

tower and Heliostat

array.

(X-band)

Polarimetric SAR


Predator UAV

–High-resolution Ku-band spotlight SAR: 0.1m

resolution

–Stripmap SAR at arbitrary angles: 0.3m resolution

–Exoclutter Moving Target Indicator (MTI)

–Near-real-time coherent-change detection (CCD)

–Extended range operation: 33 km with 4 mm/hr rain

or 55 km without rain at 0.3-m resolution

–Low weight and power: 119-lb total weight, < 1.2-kW

prime power

General Atomic’s AN/APY-8 Lynx Radar in production

Predator UAV

EE542 Microwave Engineering - KAISTma.kaist.ac.kr/lecturenote/2014_Fall/1_Course overview.pdf · 7...

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