Analysis and Applications of Microwave Electronics · Microwave Electronics Lab Analysis and Applications of Microwave Electronics Catherine A. Allen and Tatsuo Itoh Department of

1

Microwave Electronics Lab

Analysis and Applications of Analysis and Applications of Microwave ElectronicsMicrowave Electronics

Catherine A. Allen and Tatsuo Itoh

Department of Electrical EngineeringUniversity of California, Los Angeles


• Metamaterials ApplicationsElectronically-Scannable Leaky Wave Antenna

2D Conical Beam Antenna

• Retrodirective Array Systems60 GHz 4th Subharmonic Phase Conjugate System

Full Duplex System with Exclusive Uplink/Downlink Modulation

• Novel Antenna Design and ApplicationsBroadband Quasi-Yagi Antenna

Single RF Channel SMART Antenna

Self-Biased Receiver System using Sector Antenna

Outline

2


β

ω0cβω −=

ILH

GUIDANCE

IVRH

GUIDANCE

IILH

RAD.

IIIRH

RAD.

0cβω +=

0ω

Dominant mode operation ( n = 0 )

Efficient broadside radiation @ ω0

Backward (II. LH ) and forward (III. RH) radiation

1 10 0

0 0

2 /s i n s i n

n dk k

β π βθ − −⎛ ⎞ ⎛ ⎞+

= =⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠

stub (via) shorted :B

capacitor alinterdigit :A

Z Z

L2CL2CRL 2 RL 2

LL RC

Y

A B

+ 1cos (1 '( ) '( )) /Z Y dβ ω ω−= +

1 1'( )2 R

L

Z j Lj C

ω ωω

⎛ ⎞= +⎜ ⎟

⎝ ⎠

1'( ) RL

Y j Cj L

ω ωω

= +

Electronically-Scannable Leaky Wave Antenna


Scanning angle is dependent on inductances and capacitancesIntroducing varactor diodes

Capacitive parameters are controlled by voltagesDispersion curves are shifted vertically as bias voltages are variedRadiating angle becomes a function of the varactor diode’s voltages

Scanning angle is dependent on inductances and capacitancesIntroducing varactor diodes

Capacitive parameters are controlled by voltagesDispersion curves are shifted vertically as bias voltages are variedRadiating angle becomes a function of the varactor diode’s voltages

0ω

0RHβ > 0LHβ <0β =

ω

0( )ck

ω ββ= +=

1V

1V2V

2V

3V

3V

0kβ

1

0

( ) sinVk

− ⎡ ⎤βθ = ⎢ ⎥

⎣ ⎦

1

0

( )( ) sin VVk

− ⎡ ⎤βθ = ⎢ ⎥

⎣ ⎦


3


Reverse biasing to VaractorsAnodes of varactors : GND Cathodes of varactors: Biasing

The cathodes of three varactors in the same direction

Only one bias circuitry in unit cellSeries and Shunt Varactors

Fairly constant characteristic impedance

Additional degree of freedom for wider scanning range

Back to back configuration of two series varactors

Fundamental signals : in phase and add up

Harmonic signals: out of phase and cancel

Reverse biasing to VaractorsAnodes of varactors : GND Cathodes of varactors: Biasing

The cathodes of three varactors in the same direction

Only one bias circuitry in unit cellSeries and Shunt Varactors

Fairly constant characteristic impedance

Additional degree of freedom for wider scanning range

Back to back configuration of two series varactors

Fundamental signals : in phase and add up

Harmonic signals: out of phase and cancel

varactor+

var,RL var,LC var,LC var,RL

1,RL 1,LC 1,LC 1,RL

1,LL

var,RC 1,RC 2,LLDCL

DCV

Z Z

Y

A′ B′

A′

B′GND

GND inductor

Bias Configuration



Scanning Range ∆θ = 99º (-49º to +50º) Backward, forward, and broadside

Biasing Range ∆V = 21 V ( 0 to 21 V)Fixed operating frequency : 3.33 GHzMaximum Gain: 18 dBi at broadsideAntenna dimension:

Scanning Range ∆θ = 99º (-49º to +50º) Backward, forward, and broadside

Biasing Range ∆V = 21 V ( 0 to 21 V)Fixed operating frequency : 3.33 GHzMaximum Gain: 18 dBi at broadsideAntenna dimension:

38.34 (5.87 )stripeffcm µλ

38.34 (5.87 )stripeffcm µλ

010−20−10−0

030+

60+60−

30−

V = 18 V, LH ( β < 0)010−20−10−0

030+

60+60−

30−

V = 3.5 V, Broadside ( β = 0 )

010−20−10−0

030+

60+60−

30−

V = 1.5 V, RH ( β > 0)

0 2 4 6 8 10 12 14 16 18 20 22Reverse bias voltage [V]

-60

-40

-20

0

20

40

60

Scan

ning

ang

le [d

egre

e]

Theory from parameter extractionMeasurement


4


BeamwidthBeamwidth Tuning Capability with Tuning Capability with NonNon--Uniform BiasingUniform Biasing

BPSK Data Transmission TestBPSK Data Transmission Test

-90 -60 -30 0 30 60 90Angle [degree]

-60

-50

-40

-30

-20

-10

0(N

orm

aliz

ed) R

ecei

ved

Pow

er [d

Bm

(dB

)]

Normalized, non-uniform, measurementNormalized, non-uniform, theoryUniform 5VUniform 8VUniform10V

-90 -60 -30 0 30 60 90Angle [degree]

-60

-50

-40

-30

-20

-10

0

(Nor

mal

ized

) Rec

eive

d Po

wer

[dB

m (d

B)]

Normalized, non-uniform, measurementNormalized nonuniform distribution from theoryUniform 0VUniform 1VUniform 2VLH RH

0 50 100 150 200

Vol

tage

[V]

Dem odula ted waveform for RX Dem odula ted wavefrom for TX Reference waveform

T im e [nS]



2-D Model

• CR, LR→ Conventional (RH) Transmission Line

• CL, LL→ LH Transmission Line, series capacitance, shunt inductance

Mushroom Unit Cell

2CL

LL

2CL

2CL2CL


5


Γ X M Γ0

5

10

15

20

25

30Fr

eque

ncy

(GH

z)

RH Mode

LH Mode fΓ1

fX2

fX1

fM2

fΓ2

fM1

Γ X

M

kx

ky

(-π/a, π/a)

(-π/a, -π/a) (π/a, -π/a)




θ = sin-1 (β/k0)

Vg

Vg

Vp

Vp

θ θ

θ θ

Right-Handed

Left-Handed

β

β

6


-10

-30

0

-20

f = 9.3 GHz

f = 9.5 GHz

f = 11.0 GHz

f = 10.1 GHz f = 15.0 GHz

f = 13.0 GHz

LH RH

• LH RegionCone closes as f ↑

• RH RegionCone opens as f ↑

• Minimum gain:Minimum gain:12.4 dB12.4 dB



[ ]11

1 1 1

1

1 1

cos( ) cos( )1 cos(( ) ) cos(( ) )2

IF RF LO LO

RF L LO RF RFO

RF

LO RF R

F

F

RV V t V t

V V t t

ω

ω ω

θ

ω θ

ω

ω θ

= + ×

= + + +− −

[ ]

2 1 1

21 1

1

1 1

1 (cos(( ) )) cos( )2

1 cos(( ) ) cos(( ) )4

RF RF LO LO LO

RF LO RF R

LO RF RF

L F R FO I F

V V V t V t

V V t t

ω

ω

ω ω θ

ω ω θ θ

= −

+

×

= + −

−

−

ωRF1,

ωLO

1/4 ωRF1

LPFω

IFθ

RF1ω

RF2,−θ

RF1

4th Subharmonic Phase-Conjugated Retrodirective Array

7


• Circuit size : 15 × 25 mm2

• Four-element antenna array w/ 0.6 λ

• Subharmonic mixer w/ APDP• Substrate : εr = 9.8, h = 5 mils

4th Subharmonic Phase-Conjugated Retrodirective Array


RF IFi.e. RHCP =‘1’

LHCP = ‘0’

Receiver Polarization modulator

PolarizationdetectorTransmitter

• Received information contained in time domain (AM, BPSK, etc.)

• Retrodirected information contained in polarization

• Limited for line of sight use due to scattering effect on polarization

Exclusive Uplink/Downlink Modulation Retrodirective Array

8


Case 1: V1=V2

(Co-directional Diode Current)

Case 2: V1=-V2

(Anti-directional Diode Current)

-(-90)-180=-90°

-(90)=+90°

Vout

0°

0°

Hout

0°

0°

Hin

-90°

-90°

Vin

LHCP (-z prop)

LHCP(-z prop)

Pol-Sensein

V1=-V2

V1=V2

V(data)

RHCP(+z prop)

LHCP(+z prop)

Pol-Senseout



LHCP Receiver

Polarization modulatingretrodirective array

RHCP Transmitter

LHCP Transmitter

-90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90Angle [degrees]

-35

-30

-25

-20

-15

-10

-5

0

Rel

ativ

e A

mpl

itude

[dB

]

Send RHCP Send LHCP

V1=-V2 (resend opp. pol)

-90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90Angle [degrees]

-30

-25

-20

-15

-10

-5

0

Rel

ativ

e A

mpl

itude

[dB

]

Send RHCPSend LHCP

V1=V2 (resend same pol)


9


0 2 4 6 8 10 12 14 16 18 20

Time [microsec]

-0.0015

-0.001

-0.0005

0

0.0005

0.001

0.0015

Am

plitu

de [V

]

-0.025

-0.02

-0.015

-0.01

-0.005

0

0.005

0.01

0.015

0.02

0.025

Am

plitude [V]

Received signalTransmitted signal

0 2 4 6 8 10 12 14 16 18 20Time [microsec]

-6

-4

-2

0

2

4

6

Am

plitu

de [V

]

-0.5

-0.3

-0.1

0.1

0.3

0.5

Am

plitude [V]


Received signal at receiver array (transmitted by transmitter-time domain)

Recovered polarization modulation data

0 2 4 6 8 10 12 14 16 18 20Time [microsec]

-6

-4

-2

0

2

4

6

Am

plitu

de [V

]-0.5

-0.3

-0.1

0.1

0.3

0.5

Am

plitude [V]


RHCP Transmitter LHCP Transmitter



W2

driver dipole

W1

W1

W3 W4

W5

L1

L2

L3

via

microstrip ground(reflector)

director

L4

h

-Impedance Bandwidth:

S11 < -10 dB

55 % form 3.9 GHz to 7.0 GHz

-Constant Gain Bandwidth:

antenna gain of 3~5 dB

70 % form 3.8 GHz to 7.6 GHz

2 3 4 5 6 7 8 9 10

Frequency (GHz)

-30

-25

-20

-15

-10

-5

0

5

Ret

urn

loss

(S11

) (dB

)

measurement

HFSS

measured gain

Broadband Quasi-Yagi Antenna

10


FTBR = 14 dB @ 3.8 GHz

X-pol. < -20 dB @ 3.8 GHz


X-pol. < -21 dB @ 5.0 GHz


X-pol. < -18 dB @ 6.0 GHz


X-pol. < -13 dB @ 7.6 GHz

0

45

90

135

180

225

270

315

-10

-10

-20

-20

-30

-30

-40

-40

-50

-50-60

3.8 GHz Eco5.0 GHz Eco

3.8 GHz Ex5.0 GHz Ex

6.0 GHz Eco7.6 GHz Eco

0

45

90

135

180

225

270

315

-5

-5

-10

-10

-15

-15

-20

-20

-25

-25

-30

-30

-35

-35-40

-40-45

6.0 GHz Ex7.6 GHz Ex



d=300 mm

Tx Rx

Absorber

d

29 mm

27 mm

2 3 4 5 6 7 8 9 10

Frequency (GHz)

-80

-70

-60

-50

-40

-30

-20

-10

0

Ret

urn

loss

of S

11 a

nd S

22 (

dB)

Tran

smis

sion

loss

of S

21 (d

B)

measured S11

measured S22

measured S21


11


Group delay ripple less than 0.06 ns2 3 4 5 6 7 8 9 10

Frequency (GHz)

-25

-20

-15

-10

-5

0

5

10

15

20

Gro

up D

elay

ripp

le (n

s)

2 3 4 5 6 7 8 9 10

Frequency (GHz)

-200

-150

-100

-50

0

50

100

150

200

Phas

e (d

eg)

17 18 19 20 21 22 23 24

-30

-20

-10

0

10

20

30 Am

plitude (KV)

17 18 19 20 21 22 23 24

time (ns)

-0.8-0.6-0.4-0.2

00.20.40.60.8

Am

plitu

de (K

V)

Transmitted pulse

Received pulse


Gaussian Pulse Pulse width : 4ns


N-channel array requires N individual receiver chains

Each channel must be well matched and calibrated

Digital Signal Processing / Beamforming

LNAs Mixers

LPF ADC

LPF ADC

LPF ADC

Digital Signal Processing / Beamforming

LNAs Mixers

LPF ADCLPF ADC

LPF ADCLPF ADC

LPF ADCLPF ADC

Single RF Channel SMART Antenna System

12


SMILE (Spatial MultIplexing of Local Elements) schemeSequential switching samples signal at each element

Sampling rate greater than Nyquist rate

Parallel feed network retains all signal information

Sampling frequency limits signal modulation bandwidth

Switching waveform

Г=1(when switch is open)



4-Element Antenna Array

MUX

Feed Network with Single RF Output

LNA MUXNEC32485C

Pseudomorphic HJ FET

(LNAs) as switching element

Low-noise switching

improves overall noise figure

compared with passive

switch

No current required to

drive switchingLNA MUX with patch

antenna element at 5.8 GHz


13


Synthesized BeamformingBeam formed indirection of source

Null formed in direction of unwanted

signal

DOA EstimationProper recovery of IF channel data

allows advanced beamforming

algorithms and DOA estimation

MUSIC algorithm detects proper

direction of signals-100 -80 -60 -40 -20 0 20 40 60 80 100

-25

-20

-15

-10

-5

0

Angle

Synthesized PatternDOA estimation

-100 -80 -60 -40 -20 0 20 40 60 80 100-30

-25

-20

-15

-10

-5

0

Angle

Synthesized PatternDOA estimation

Single Source

Two Sources



0 5 10 15 20 25 30 35 40 45 50-0.3

-0.2

-0.1

0

0.1

0.2

0.3Before Digital Beamforming

0 5 10 15 20 25 30 35 40 45 50-0.3

-0.2

-0.1

0

0.1

0.2

0.3After Digital Beamforming

Time µs

Two Source Data RecoveryIncoherent demodulation does not

resemble a digital pattern

Interference ‘nulling’ shows spatial

filtering

0 5 10 15 20 25 30 35 40 45 50-0.3

-0.2

-0.1

0

0.1

0.2

0.3Before Digital Beamforming

0 5 10 15 20 25 30 35 40 45 50-0.3

-0.2

-0.1

0

0.1

0.2

0.3After Digital Beamforming

Time, us

Single Source Data RecoveryCoherent summation = clearer pattern

More evident for angles off broadside


14


Receiver

Vdc

VRF

Dual-FedCircular Sector

Antenna

Feed 1

Feed 2

Data

Rectenna

LNA

LPFDiode

LPFSelf-Mixer

RF signal+ Carrier f

of

o+f

mfo-f

mReceiver

Vdc

VRF

Dual-FedCircular Sector

Antenna

Feed 1

Feed 2

Data

Rectenna

LNA

LPFDiode

LPFSelf-Mixer

RF signal+ Carrier f

of

o+f

mfo-f

m

Antenna BPF LPF for DC

Conventional Rectenna

LPF for DC

Harmonic-TunedCircular Sector Antenna

Proposed Rectenna

Self-Biased Receive System Using Sector Antenna

New Design

Compact and Efficient Design

Eliminate the BPF

Higher-order harmonic rejection

Important Roles of Filters

BPF : Block the regenerated harmonic power from the diode

LPF : Block all RF power


d

120°

Port 2

Port 1

d

120°

Port 2

Port 1

LayoutLayout Measured S-parametersMeasured S-parameters

Port 1 is for a receiver system

Port 2 is for a rectenna0 2 4 6 8

-30

-20

-10

0

3rd Harmonic2nd HarmonicFundamental

S-pa

ram

eter

s [d

B]

Frequency [GHz]

S11S21S22

0 2 4 6 8-30

-20

-10

0


S-pa

ram

eter

s [d

B]

Frequency [GHz]

S11S21S22

0 2 4 6 8-30

-20

-10

0


S-pa

ram

eter

s [d

B]

Frequency [GHz]

S11S21S22

S11S21S22


15


-10 -5 0 5 10 15 200

10

20

30

40

50

60

70

80

90

Effic

ienc

y [%

]

Input Power into Rectifier [dBm]

100 Ω150 Ω200 Ω250 Ω300 Ω

-10 -5 0 5 10 15 200

10

20

30

40

50

60

70

80

90

Effic

ienc

y [%

]

Input Power into Rectifier [dBm]

100 Ω150 Ω200 Ω250 Ω300 Ω

100 Ω150 Ω200 Ω250 Ω300 Ω

Rectenna EfficiencyRectenna Efficiency

2Load

oA

V /Rdc output power=incident RF power P

η =

Up to 82% efficiency at the optimum load resistance of 250Ω for 14dBm input power

Overall Efficiency



Digital Data ReceivingDigital Data Receiving

•1-kHz digital data in the ASK format

Transmitted signal

Received signal

ImpedanceTransformer

HP33120AFunction

Gen.

HP8340ASynthesized

Oscillator

HP8349BMicrowaveAmplifier

DL2700Digital

OscilloscopeSelf-Mixing

Rectifying Circuit

DC power

fm=1kHz

RF signal+ Carrier

fo fo+fmfo-fmfo=2.4GHz


16


Contributing Authors:

Sungjoon LimCatherine Allen

Anthony LaiChristophe Caloz

Ji-Yong ParkKevin Leong

Cheng-Jung LeeDarren GoshiSang-Min Han

Tatsuo Itoh


MICROWAVE ELECTRONICS LAB

Room63-129, Engineering IVUniversity of California, Los

Angeles405 Hilgard Avenue, Los

Angeles, CA 90095

Phone 310.206.1024

Documents

Analysis and Applications of Microwave Electronics · Microwave Electronics Lab Analysis and Applications of Microwave Electronics Catherine A. Allen and Tatsuo Itoh Department of