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Microwave Frequency Band (300MHz300GHz)

VLF 3K30K

Lf 30K300K

MF 300K3 M

HF 3M30M

VHF 30M300M

UHF 300M3G

SHF 3G30G

EHF 30G300G

(cm) = 30/f(GHz) 1m1mm

IR

Visible

UV

X

Cosmic

mm waves

Band Freq(GHz)

L 1-2

S 2-4C 4-8

X 8-12

Ku 12-18

K 18-27

Ka 27-40

1

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2

Relative Power

"B" is in honor of Alexander Graham Bell

dBm power relative to 1 milliwatt

dBW power relative to 1 watt

dBk power relative to 1 Kilowatt

dBi the forward gain of an antenna compared to an isotropic

antenna

dBd the forward gain of an antenna compared to a half-wavedipole

0dBd = 2.15 dBi = [ 10 log(1.643) ]

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4

Reflection Coefficient

VSWR 2:1

Refln Co-efft 1/3

Return Loss -10 dB

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Standing Waves

5

http://en.wikipedia.org/wiki/File:Standing_wave_2.gif

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Maxwells Equations

6

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8

DivergenceDivergence Net Outward flow

Flower Fragrance

Fountain WaterAntenna EM Wave

100 ml

100 ml

Zero+ ve

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9

Curl

Rotational + Translational motion

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10

Why Maxwells Equations?

Electromagnetic wave effectsthat, until now, were

in the domain of the microwave engineer are

becoming a limiting factorin digital circuit operation

Maxwells Equations are literally valid from dc to

light

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Why Maxwells Equations?

11

Dimensions of devices/components are wavelength

comparable

Significant change in phase of an electrical signal

(V/I) over the physical length of the device

At higher frequencies, Maxwells Equations replace

Basic Circuit Theory

Circuit Theory is a subset of Electromagnetic Field

Theory

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Why Maxwells Equations?

High speed digital signalscan spuriously

Distort as they propagate along the metal

circuit paths

Couple (cross-talk) from one circuit path to

another

Radiate and create interferences to other

circuits and systems

12

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High Speed Electronics

a conventional dual in-line integrated-circuit package

13

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High Speed Electronics

coupling and crosstalk of a high-speed logic pulse

entering and leaving a microchip

14

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15

Why not Maxwells Equations?

Numerical methods for electromagnetic modelling

attempt to solve fundamental field equations

directly, subject to boundary conditions posed by

the geometry

http://www.ece.northwestern.edu/ecefaculty/Al

len1.html

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