Microwave Electronics Lab Outline 1. Novel MIM Implementation of CRLH Structure 2. Electronically-Scanned 1D Leaky-Wave Antenna 3. 2D Leaky-Wave Antenna.

Microwave Electronics Lab

Outline

1. Novel MIM Implementation of CRLH Structure

2. Electronically-Scanned 1D Leaky-Wave Antenna

3. 2D Leaky-Wave Antenna

4. 3D LH Metamaterial

5. RH/LH Surface Plasmons


Novel CRLH Structure Implementation

microstripline

seriesinterdigitalcapacitor

shuntspiral

inductor

T-junction

via toground

unit cell

interdigitalcapacitors

shorted stubinductors

Interdigital C & stub L

MIM-C

GP

shortedstub

MIM-C

GP

shortedstub

MIM C & stub L

LH RH

150 % BW

CRLH line

• C’ larger more compact• multilayer LTCC


Electronically Scanned LW Antenna

2 3 4 5 6 7-90

-60

-30

0

30

60

90

Sca

nn

ing

An

gle

(d

eg

)

Frequency (GHz)

II.LW-LH

III.LW-RH

0f0 2c maxf

x y

z

θ

I.Guided

-LH

0

30

60

90

120

150

180

Initial Backfire-to-Endfire CRLH Antenna

Frequency-Scanned Beam

x

z

ysource

bwd

fwd

broadside

longitudinalpolarization

Novel Electronically-Scanned Antenna

Preliminary Results

-5

-4

-3

-2

-1

0

0

30

60

90

120

150

180-5

-4

-3

-2

-1

0

0 V 5 V 15 V 27 V

LHRH

@ 3.49 GHz: Scanning range is +35 (̊@ 0V) to -9 (̊@ 27V)

90

30

0

-30

-60

-90

60

-5

-4

-3

-2

-1

0

0

30

60

90

120

150

180-5

-4

-3

-2

-1

0

0 V 5 V 15 V 27 V

LHRH

@ 3.49 GHz: Scanning range is +35 (̊@ 0V) to -9 (̊@ 27V)

90

30

0

-30

-60

-90

60

seriesvaractor

shuntvaractor

DCblock

biaswires

0asin k

1R R L LL C L C

0R

R

L

L

LZ

C

L

C


2D Leaky-Wave Antenna: Stucture

2.5D Textured Structure: Meta-Surface (“open”)

2D Lumped Element Structure: Meta-Circuit (“closed”) RH

yz

x

RC

2RL

2RL2RL

2RL

LH

LL

2 LC

2 LC

2 LC2 LC

yz

x

2D interconnection

y

x

Chip Implementation

Enhanced Mushroom Structure Uniplanar Interdigital Structure

top patch

ground plane

capspost

Unit cell

top patch

sub-patches

ground plane

via


2D Leaky-Wave Antenna: Initial Result

Measured Frequency Scanning

Initial Prototype (top view)

source

0 (endfire)

180 (backfire)

90 (broadside)

0 30 60 90 120 150 180 210 240 270 300 330 360

angle (degrees)

-25

-20

-15

-10

-5

0

No

rmal

ized

Po

wer

(d

B)

2.5GHz2.7 GHz3 GHz

ground plane

via

interdigitalcapacitor

x

y

Structure

Dispersion diagram

xk ,X Y,X Y

LC

LL

RL

RC

0 RHRH

LH LH

TM


2D CRLH Surface: Extension of 1D Structure

2RL

RC LL

2 LC

2 LC

2 LC

2 LC2RL

2RL

2RL

x

y

ground plane via

interdigitalcapacitor

x

ysubstrate

Alternative Design: Mushroom Structures

Interdigital

Implementation

(2x2)

Goal:FULL SPACE SCANNING for

functional 2D LW antenna

Assumptions:• model solution to Maxwell• small enough for accurate • matching technique available• appropriate feeding mechanism

• Uniplanar• Excellent in 1D

Circuit

Model

Open Closed

Sievenpiper can include radiating slots

Multiplanar !


Validation of CRLH Approach and Model in 2D

Fre

quen

cy (

GH

z)

8

4

2

0X M

closed (TE)

air modeai

r m

ode

6

open (TE)

open

open (TE)

closed (TE)

closed

theory

full-wave simulation

theory

full-wave simulation

CRLH Model & Full-Wave

Dispersion Diagram for

Closed and Open Mushroom

Observations:

• Excellent agreement for TEM Maxwell ok with 2D open CRLH

• Leakage factor small enough can be neglected in model

accurate and Z0

• Accurate LW radiation predictions expected

CRLL2C Ly

2CLx

2C Ly

L Ry/2

LRx/2

LRx/22CLx

L Ry/2

x

y

y

x

#2quasi-TEM

#1 TE

Extraction Technique:

Cutoffs & Bloch Impedance


Fields Distributions in Interdigital Structure

Full Wave Dispersion Diagram Modes Distributions

3

3.5

4

4.5

5

5.5

6

6.5

7

0 0.1 0.2 0.3 0.4 0.5

2E

3E

4E

2H

3H

4H

2S

3S

4S

x

x

x

Mode2: LH, QUADI-TEM

Mode 3: RH, TE

Mode 4: RH, LH, QUADI-TEM

X3

4

5

6

7

TM

(GHz)f

RC

1

L RL C

1

R LL C


Array Factor Approach of LW Structures (1D)

Phased Array Leaky-Wave Structure

1 sin0

1

Nj n kp

n

AF I e

• linear phase:

• constant magnitude:

• excitation: feed at each element

• array factor:

0n n

0 ,nI I n

DISCRETE EFFECTIVELY HOMOGENEOUS

1 sin

1

Nj n kp

nn

AF I e

• linear phase : uniform structure

• exponentially decaying magnitude:

• excitation: induced by propagation

• array factor:

10with n p

nI I e

directivity N

x

z

p

1 1,I

2 3 40

0I 0I 0I 0I 0I

2 2,I 3 3,I 4 4,I 5 5,I

0I 01 sinn n kp

x

z

p 2 3 40

0I

0nxI e

0I

01 sinn n kp


Comparison Ckt/AF and Measured PatternsBackward, 3.5 GHz Broadside, 3.9 GHz Forward, 4.3 GHz

meas. meas. meas.

N = 25 N = 100

X

(G

Hz)

f

RH

LH


Array Factor Approach for 2D LW Structures

1 sin cos1

1

1 sin sin

11

where,

x x

y y

xm yn

Mj m kp

xm mm

Nj n kp

yn nn

AF S S

S I e

S I e

0 0

0 0

sin cos

sin sinx x

y y

kp

kp

xpx

yz

yp

M

90

xk yk

,n x yk k

0LH

RH

radiationcone

Brillouin Zone

X


3D-LH Metamaterial: TL Analysis

x

y

z

oxA

oxBo

xC oxD

iyA

iyB

iyC

iyD

oyA

oyB

oyC

oyD

ozA

ozB

ozC

ozD

izA

izB

izC

izD

ixA

ixBixCixD

0V

gA gB

gC gD

0ixI

0oxI0i

yI

0oyI

0ozI

0izI

igI

0ixV

0iyV

0oyV

0oxV

0izV

0ozV

xI

xjk axI e

yI

yjk byI e

zI

zjk czI e

xV

xjk axV e

yV

yjk byV e

zV

zjk czV e

0igV

0ogI


3D-LH Metamaterial: TL Dispersion Diagram

LH

RH

1 nH, 1 pHR L R LL L C C


3D-LH Metamaterial: Possible Unit Cell

RL

LCRC

LL

RL

RC

LC

LL


3D-LH Metamaterial: Preliminary Result

sgn sgnp gv v

LH

So far, still flat,whereas LH => negative;should be achievable be reducing series Lor increasing series C


RH / LH Surface Plasmon in LC Network

0 052.8 , 7.5 , 422.5 , 60 , 2.83 ,R R L LC fF L nH C fF L nH f GHz f f

RH LH

zRk zLk

xk

xkz

x

RH LH

zRk zLk

xk

xk LR z

x

Voltage Magnitude

Voltage Phase

RH LH

RC

2RL

2RL2RL

2RL

LL

2 LC

2 LC

2 LC2 LC

zx

zRk zLk

xk

xk

RH / LH Transmission Line Interface

0 : L R L Rn n

0

RL

LH RH

R R RL C

1L

L LL C

04

1

R R L LL C L C

MICROWAVE SP Low-loss SP frequency not related to physical length


RH / LH Interface Plasmons (TM)

2

2 2 2 22

1 1

2 2 1 20

1 2

0 and 0 : 1 and 1

cste 0 and cste 0

0,

pr r

x SPk k

2xck

SP

xk

SP

lightline

loosely bound

tightly bound

p

non-radiativeSP

radiativeSP

SP gap

Rexk

Rexk

Imxk

2 20 1 1 2

2 21 0 1 1 1 2 1 22

2 2

, 0 : ,1

1=j and =j

1

1 OR 1

x r r

z r r z z

k k

k k k k

conventional SP

metal: 2 0

diel.: 1 0

x

zLH SP

LH: 22 , 0

RH: 1 1, 0

x

z

Reference: R. Ruppin, “Surface Polaritons of Left-Handed Medium”, Phys. Lett. A 277 (2000), 61-64

2 2 2 22 2

1 1

1 2 1 2 2 12 2 20 0 1 12 2 2

2 1

1 10 and 0 : and

and

,1

L L

R R

r r r r r rx r r

r r

L C

C L

k k k

2 1 2 1with ,


Dispersion Curves With Air Line and RSP

1 2 1 2 2 12 20 2 2

2 1

Dispersion relation (TM):

r r r r r rx

r r

k k

1 0 1 0

1 , 1 , 30

, , 0, 0L L

TL TL

L nH C pF a mm

C L

1 0 1 0

1 , 0.01 , 30

, , 0, 0L L

TL TL

L nH C pF a mm

C L

one SP, non radiative

,1 ,29.76 GHz 0.009 GHzSP SPf f j

1 0 1 0

1 , 0.01 , 30

, , 10 , 1L L

TL TL

L nH C pF a mm

C pF L H

,1 ,29.37 GHz 10.08 GHzSP SPf f

SP

two partly radiative SPs + 1 strange

Still Under Investigation !!!

,1 ,29.77 GHz 9.77 GHzSP SPf f j

Funny, no ?

one SP, partly radiative

branchpoint

Brewster angle

NOVELTIES:• SPs exist• -scanned Brewster angle• 2 Brewster angles possible

Microwave Electronics Lab Outline 1. Novel MIM Implementation of CRLH Structure 2. Electronically-Scanned 1D Leaky-Wave Antenna 3. 2D Leaky-Wave Antenna.

Documents