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

2. 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:

3. MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 GaAs Monolithic Nonlinear Delay Lines Layout of the GaAs Monolithic NDL Less than 3dB insertion loss up to 20 GHz 80 ps useable delay range

4. MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 Low Parasitic Schottky Varactor Diode Structure Employ Small Active area to reduce parasitic capacitance Employ Mesa etch isolation instead of proton-bombardment to provide better isolation between active devices, also reduce parasitic capacitance between anode and n+ layer Anode Cathode

5. MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 Linear Tapered Slot Antenna HFSS Simulation E-plane pattern H-plane pattern Simulated antenna structure

6. MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 CPW to Slot Transition Design Back-to-back CPW to Slot transition with air-bridge to enhance single mode propagation Simulated and Measured results of the Back- to-back CPW to Slot transition

7. MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 Fermi-Tapered Slot Antenna Fermi-tapered antenna structure Field DistributionE-H Field Pattern [4] “A MM-Wave Tapered Slot Antenna With Improved Radiation Pattern,” S. Sugawara, et.al. IEEE MTT-s 1998

8. MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 Linear Tapered Antenna with Corrugation Structure in Narrow Edge Case Linear tapered antenna with corrugation structure E-H Field Pattern [5] “Characteristics of a MM-Wave Tapered Slot Antenna With Corrugated Edges,” S. Sugawara,et.al. IEEE MTT-s 1997

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

10. MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 2-Dimensional LTSA Array Simulation E-plane H-plane 4 x 4 two dimensional linear tapered slot Antenna array simulation

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

12. 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

13. 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

14. MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 4  4 Two Dimensional Beam Steering Array Antenna Nonlinear Delay Line Bias Board Power Divider

15. MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 1  4 Linear Tapered Slot Antenna Array with/without Corrugations E-plane H-plane 1x4 array without corrugation 1x4 array with corrugation

16. MVE MURI 99 Kick-off Meeting R. Barker, Technical Monitor Started 1 May 99 October 1999 Summary and Ongoing Activities The usage of Nonlinear Delay Line as wide band true time delay component in phased antenna system has been discussed. The design of a wide band true time delay controlled phased antenna array system has been discussed. A proof-of-principle hybrid system has been built and tested by Millimeter wave technology group, UC Davis. The GaAs monolithic Nonlinear Delay Line (NDL) is currently under fabrication by the Army Research Laboratory, Adelphi, Maryland. Two dimensional true time delay controlled phased antenna array is currently under development at UC Davis.