MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 UC Davis...

MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor

Started 1 May 99 October 1999

UC Davis Millimeter Wave Vacuum/ Solid-State Hybrid Technologies

S.A. Rosenau, C. Liang, W-K. Zhang(a), C.C. Chang, K. Liu, C.W. Domier(a), N.C. Luhmann, Jr., J.P. Heritage

Department of Electrical and Computer Engineering, University of California, Davis, CA 95616

(a) Department of Applied Science, University of California, Davis, CA 95616



Outline

• Frequency Multiplier Grid Arrays– Frequency Doubler Grid Arrays

– Frequency Tripler Grid Arrays

• Quasi-Optical Switch Arrays– High Speed Switch Arrays

– MEMS based Switch Array Power Control Array Tunable Filter

• Delay Line Controlled Phased Antenna Arrays

• Gated Silicon Field Emission Array Photocathodes



State-of-the-Art in High Power Sources

0.01

1

100

104

106

0.1 1 10 100 1000

Ave

rage

Pow

er (

W)

Klystron

Frequency (GHz)

Gridded TubeSolenold Focused

Coupled-Cavity TWT

Periodic Permanent Magnet Focused

Helix TWTStatic

InductionTransistor Si BJT

GaAs MESFET

Quasi-OpticalSolid State

Arrays

MPM

Gyrotron

Solid-state/ vacuum hybrid devices extend the state-of-the-art in both technology areas. Frequency multiplier grid arrays driven by MMPMs can provide 10 to 30 Woutput power at frequencies of 50 to 110 GHz.



Solid State–MVE Hybrid Devices and Configurations

The combination of novel layeredsemi-conductor device structures andphotonic crystals, together with thenewly developed microwave / millimeterwave power module (MPM / MMPM)promises revolutionary, compact highpower sources in the 30-300 GHz regionfor next generation DoD systems.

Output FIlter / Matching Element

Input Filter

Input Matching Element

Varactor Device

Antenna Lead

RF Input (f )o RF Output

(3f )o

AlN Cooling Plate

Photonic Band Gap (PBG) Waveguide Walls

Millimeter Wave Power Module

(MMPM)

Multiplier Array

Schematic of an MMPM Driving a Tripler Grid Array with a PBG Wall

Transition from Metal Waveguide to Overmoded PBG Waveguide

Transition from Overmoded PBG Waveguide to Metal Waveguide

Antenna Lead

MetalActive Regionn+

SubstrateIsolation

Top View Cross Sectional View

E

Back-to-Back Tripler Layout

E Field

Antenna Leads Back-to-Back

Varactor Diodes

V

C

C-V Curve

V

I

I-V Curve

Monolithic Frequency Tripler Array



Preliminary Frequency Tripler Results

• 141 mW output power at 90 GHz• 3.7 % efficiency

(reduced efficiency due to low yield)• 270 devices• 0.5 mW per device

• 2.5 GHz (3%) tuned output bandwidth

Multiple Quantum Barrier Varactor (MQBV) devices were used in an overmoded waveguide frequency tripler grid array.

0

0.5

1

1.5

2

2.5

3

3.5

30 31 32 33 34

Effi

cie

ncy

(%

)Input Frequency (GHz)

0

50

100

150

200

0

0.5

1

1.5

2

2.5

3

3.5

4

0 1 2 3 4

Output Power (mW)

Efficiency (%)

Ou

tpu

t Po

we

r (m

W)

Efficie

ncy (%

)Input Power (W)



Schottky Varactor Devices

• Frequency doubler grid arrays using Schottky varactors fabricated by Martin-Marietta have been tested.

• Cmin = 15 fF, Cmax = 60 fF resulting in Cmax/Cmin = 4

• Rs = Rdiode + Rstrip = 6 Ω

L strip

ba

___ C diode

b

a___ R diode

C parasitic

Rstrip

C bias

1

2



Preliminary Frequency Doubler Results

• 410 mW output power at 66 GHz• 6.7 % efficiency at 63 GHz

(reduced efficiency due to fixturing)• 56 devices• 7.3 mW per device

• 6.6 GHz (10%) tuned output bandwidth• 3.6 GHz (6%) instantaneous output

bandwidth

Schottky diodes, fabricated by Martin-Marietta (Baltimore), were used in an overmoded waveguide frequency doubler grid array.

0

1

2

3

4

5

6

7

30 31 32 33 34 35

Instantaneous Tuned

Effi

cie

ncy

(%

)Input Frequency (GHz)

0

0.1

0.2

0.3

0.4

0

2

4

6

8

10

12

14

0 1 2 3 4 5 6 7 8

Output Power EfficiencySimulated Efficency

Ou

tpu

t Po

we

r (W

)

Efficie

ncy (%

)

Input Power (W)



State-of-the-Art in Moderate/High Power Frequency Multipliers



Quasi-Optical Switch Arrays

•Millimeter-wave switches may be used in a variety of applications, including

High speed, high power handling capability electronics control systems

for smart tubes and arrays

Millimeter-wave power control systems for klystrinos.

Moderate pulse radar reflectometry for plasma diagnostics

• Beam control array technology offers the possibility of achieving high speed and

high power handling capability with increased dynamic range.

• Silicon based microelectromechanical system (MEMS) switches have the potential

to form low cost, high performance, ultra wide quasi-optical control elements for

advanced defense and commercial applications.



High Speed Switch Array System

0

5

10

15

20

54 56 58 60 62 64 66

MeasuredSimulated

Co

ntr

ast

Rati

o (

dB

)

Frequency (GHz)High Speed Switch Array with Bias Control Board High Speed Switch Array Testing Results



Microwave / Millimeter Wave MEMS Power Control Array

MEMS Based Quasi-Optical Power Control ArraySEM Photo of Single MEMS Switch Device



Driver SourceDriver Source

KlystrinosKlystrinos



Power DividerHorn Antenna Array

MEMS NDLMEMS NDL

MEMS NDLMEMS NDL

MEMS NDLMEMS NDL

Klystrinos Controlled by MEMS Nonlinear Delay Lines



Design of MEMS based QO Tunable Filter

-100

-50

0

50

100

25 30 35 40 45

Phase of W-band Tunable filter

Tune 1Tune 2

-10

-8

-6

-4

-2

0

90 95 100 105 110

Pass-Band of Tunable Filter

Tune 1Tune 2

S2

1 (

dB

)

Frequency(GHz)

-20

-15

-10

-5

0

25 30 35 40 45

Stop-Band of Tunable Filter

Tune 1Tune 2

S21

(dB

)

The MEMS Tunable QO filter consists of several LC resonant circuits fabricated on each of the wafer surfaces. Simulations predict a W-band phase tunable filter with ~30 degree phase shift from 30 GHz to 40 GHz.

Simulation Result of W-band Tunable Filter

QO MEMS Tunable Filter System



• A V-band low insertion loss and high contrast ratio switch array has

been demonstrated, with a rise/fall time < 127 psec.

• A new class of GaAs based V-band and W-band high speed monolithic

millimeter wave switch array is being fabricated.

• MEMS Switch array technology is being developed. MEMS based

quasi-optical arrays will be employed as quasi-optical power control

arrays, quasi-optical phase shifters, and tunable quasi-optical filters.

Quasi-Optical Switch Array Accomplishments and Ongoing Activities



Wideband Delay Line Controlled Phased Antenna Array

• Microwave and millimeter wave phased antenna arrays are important elements for numerous applications, including satellite or ground communications, radar, imaging systems and plasma diagnostics.

• The use of diode loaded transmission lines as the broad-band phase controlling elements in phased antenna arrays has been successfully demonstrated in broadband and low loss beam steering and delay. [1] “Novel Low-Loss Delay Line for Broadband Phased Antenna Array Applications,” W-M, Zhang,et.al. IEEE Microwave and Guide Wave Letters,1997, [2] “A Hybrid Nonlinear Delay Line-based Broad-band Phased Antenna Array System,”R. Hsia,et.al. IEEE Microwave Guided Wave Letters 1998 [3] “Monolithic GaAs Phase Shifter Circuit with Low Insertion Loss and Continuous 0-360 Phase Shift at 20 GHz,” A. S. Nagra,et.al. IEEE Microwave Guided Wave Letters,1999



GaAs Nonlinear Delay Lines as Phase Control Elements of an MMPM Array

Widebandpower divider NDL

MMPM

MMPM

MMPM

MMPM

NDL

NDL

NDL

Driver

Wideband Antenna Array



Nonlinear Delay Lines

The line has a Bragg cutoff frequency given by:

))((

1

vCCLf

Diodelineline

Bragg

The equivalent circuit of a varactor diode periodically loaded Coplanar Waveguide (CPW) line is shown below:



1-Dimensional (1 x 8) LTSA Array Simulation

Beam scanning in E-plane1 x 8 linear tapered slot antenna array

Measured pattern

Simulated result

of proof-of-principle array

2.594061014

40

measured( )

s_array( )

9090 180

90 60 30 0 30 60 9040

35

30

25

20

15

10

5

0



Proof-of-Principle Nonlinear Delay Line Controlled Phased Antenna Array

-30

-25

-20

-15

-10

-5

0

-90 -60 -30 0 30 60 90

-3 V Bias (all channels)14 psec progressive delay14 psec progressive delay (reversed)

Rel

ativ

e Po

wer

(dB)

Angle (Þ)



6m center-to-center spacing, 2m gate aperture diameter, 2m tip height.

Bo

Microwave Circuitry

Collector

Gated Field Emission Cathode

ModulatedLaser Beam

Anode

Field emission does not require heating filament.

Optical gating avoids capacitive effect associated with electrical gating.

Prebunching capability reduces microwave circuitry and shortens tube length.

Shorter tube length requires fewer magnets for beam confinement.

Shorter tube length also increases efficiency.

Optical Prebunching in Microwave Tube

Micro-fabricated Field Emission Arrays

Anode

Emitted ElectronsGate Electrical Insulator

Emitter

1000V

0 – 200V

Illustration of Field Emitter with Biasing

Gated Silicon Field Emission Array Photocathodes



Anode Current

VGate (V)50 15070 90 110 1300

2

I(A)4

6 10-4

VAnode = 500V

0.006 0.01 0.014 0.018

1/VGate (V-1)

10-10

10-8

10-6

10-4VAnode = 500V

I (A)

Fowler-Nordheim Plot

Gated Silicon Field Emission Array Photocathodes

MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 UC Davis...

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