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

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

MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 State-of-the-Art in High Power Sources 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 W output power at frequencies of 50 to 110 GHz.

MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 Solid State–MVE Hybrid Devices and Configurations

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

MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 Schottky Varactor Devices Frequency doubler grid arrays using Schottky varactors fabricated by Martin- Marietta have been tested. C min = 15 fF, C max = 60 fF resulting in C max /C min = 4 R s = R diode + R strip = 6 Ω

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

MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 State-of-the-Art in Moderate/High Power Frequency Multipliers

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

MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 High Speed Switch Array System High Speed Switch Array with Bias Control Board High Speed Switch Array Testing Results

MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 Microwave / Millimeter Wave MEMS Power Control Array MEMS Based Quasi-Optical Power Control Array SEM Photo of Single MEMS Switch Device

MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 Driver Source Klystrinos Power Divider Horn Antenna Array MEMS NDL Klystrinos Controlled by MEMS Nonlinear Delay Lines

MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 Design of MEMS based QO Tunable Filter 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

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

MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 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  Phase Shift at 20 GHz,” A. S. Nagra,et.al. IEEE Microwave Guided Wave Letters,1999

MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 GaAs Nonlinear Delay Lines as Phase Control Elements of an MMPM Array Wideband power dividerNDL MMPM NDL Driver Wideband Antenna Array

MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 Nonlinear Delay Lines The line has a Bragg cutoff frequency given by: The equivalent circuit of a varactor diode periodically loaded Coplanar Waveguide (CPW) line is shown below:

MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October Dimensional (1 x 8) LTSA Array Simulation Beam scanning in E-plane 1 x 8 linear tapered slot antenna array Measured pattern Simulated result of proof-of-principle array

MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 Proof-of-Principle Nonlinear Delay Line Controlled Phased Antenna Array

MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999  6  m center-to-center spacing, 2  m gate aperture diameter, 2  m tip height. BoBo Microwave Circuitry Collector Gated Field Emission Cathode Modulated Laser 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 Electrons Gate Electrical Insulator Emitter 1000V 0 – 200V Illustration of Field Emitter with Biasing Gated Silicon Field Emission Array Photocathodes

MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 Anode Current V Gate (V) I(A) 4 6  V Anode = 500V /V Gate (V -1 ) V Anode = 500V I (A) Fowler-Nordheim Plot Gated Silicon Field Emission Array Photocathodes