8/12/2019 Schau Bert

1/34

Antenna Lab

Vivaldi Antenna Arrays

Application to Focal Plane Array

Dan Schaubert

Anatoliy Boryssenko

University of Massachusetts Amherst413-545-2530

schaubert@ecs.umass.edu

8/12/2019 Schau Bert

2/34

Antenna Lab

Two Designs for THEA

Substrate Thickness = 3.15 mm Substrate Thickness = 1.6 mm

8/12/2019 Schau Bert

3/34

Antenna Lab

THEA Demonstration

8/12/2019 Schau Bert

4/34

Antenna Lab

Element Configurations

Metallic Fins

Ground Plane

Dielectric

Stripline Feed

Metallic Fin

Microstrip Feed

Dielectric

E

Ground Plane

E

8/12/2019 Schau Bert

5/34

8/12/2019 Schau Bert

6/34

Antenna Lab

UMass TDIE MoM-MOT code

12

34

56

78

8

16

64

48

56

40

32

24

5x1 TSA Array

8x8 TSA Array

References:

[1] A. O. Boryssenko, Phased-array workshop, Eindhoven, June 11 2001.[2] A. O. Boryssenko, D. H. Schaubert, Predicted Performance of Small

Arrays of Dielectric-Free Tapered Slot Antennas, in:Antenna App. Symp.

Digest (Monticello, IL, 2001), pp. 250-279.

[3] --, Time-Domain Integral-Equation-Based Solver for Transient and

Broadband Problems in Electromagnetics,Presented at AMEREM 2002

Conf., To be published in UWB-6,(Annapolis, MR, 2002), pp. 1-11.

8/12/2019 Schau Bert

7/34

Antenna Lab

Vias Suppress Dielectric Region Resonance

Without Vias

Example Three Scan Angles

With Vias

H-Plane Scan

8/12/2019 Schau Bert

8/34

Antenna Lab

Element Pattern in Infinite Phased Array

Dielectric-Free Antenna

Active Gain - 0.8 GHz

-20

-15

-10

-5

0

0 15 30 45 60 75 90

Theta

Relativ

edB

G(0)

G(45)G(90) G(90)

Active Gain - 1.7 GHz

-20

-15

-10

-5

0

0 15 30 45 60 75 90

Theta

R

lativ

edB

G(0)

G(45)

e

Active Gain - 2.6 GHz

-20

-15

-10

-5

0

0 15 30 45 60 75 90

Theta

Relativ

edB

G(0)

G(45)G(90)

Active Gain - 1.25 GHz

-20

-14

-8

-2

4

0 15 30 45 60 75 90

Theta

Relativ

edB

G(0)

G(45)

G(90)

8/12/2019 Schau Bert

9/34

Antenna Lab

Element Pattern in Infinite Phased Array

r= 2

Active Element Gain - 1.7 GHz

-20

-15

-10

-5

0

0 15 30 45 60 75 90

Theta

dB

Phi=0

Phi=45Phi=90

Active Element Gain - 0.8 GHz

-20

-15

-10

-5

0

0 15 30 45 60 75 90

Theta

dB

Phi=0

Phi=45

Phi=90

Active Element Gain - 2.1 GHz

-20

-15

-10

-5

0

0 15 30 45 60 75 90

Theta

dB

Phi=0

Phi=45

Phi=90

Active Element Gain - 1.25 GHz

-20

-15

-10

-5

0

0 15 30 45 60 75 90

Theta

dB

Phi=0

Phi=45

Phi=90

8/12/2019 Schau Bert

10/34

Antenna Lab

Spin Linear Radiation Patterns

H-PlaneE-Plane D-Plane

8/12/2019 Schau Bert

11/34

Antenna Lab

Configurations for Dual Polarization

On sides of box - phase centers not

coincident

Crossed at corners of box - difficultto feed at back of slot

Pair of slots forms element - reduced

bandwidth and potential anomalies

8/12/2019 Schau Bert

12/34

Antenna Lab

Circular Polarization Performance with Imperfect Elements

Element PatternsCP Patterns with

Amp + Phase Control

This antenna is not optimized for performance

8/12/2019 Schau Bert

13/34

Antenna Lab

Wideband Scan Range

E-Plane H-Plane

This antenna is not optimized for performance

8/12/2019 Schau Bert

14/34

Antenna Lab

THEA Prototype Array

Designed and fabricated at

UMass Antenna Lab, 1999

1 - 5 GHz

Approx 25cm x 25cm x

10cm Measured central element

patterns and S parameters

8/12/2019 Schau Bert

15/34

Antenna Lab

Central Element Patterns - 2.8 GHz

E-Plane H-Plane

8/12/2019 Schau Bert

16/34

Antenna Lab

Central Element Patterns - 4.0 GHz

E-Plane H-Plane

8/12/2019 Schau Bert

17/34

Antenna Lab

Central Element Patterns - 4.8 GHz

E-Plane H-Plane

8/12/2019 Schau Bert

18/34

Antenna Lab

Central Element Patterns - D-Plane

3.6 GHz 5.4 GHz

8/12/2019 Schau Bert

19/34

Antenna Lab

Central Element Gain

Broadside

500 E-Plane 500 H-Plane

8/12/2019 Schau Bert

20/34

Antenna Lab

8-by-Infinite Element Patterns

From Craeye, Boryssenko and Schaubert, ICAP 03

8/12/2019 Schau Bert

21/34

Antenna Lab

Mutual Coupling to Central Element 3 GHz

Co-Polarized Cross-Polarized

8/12/2019 Schau Bert

22/34

Antenna Lab

H-Plane Coupling Magnitude

8/12/2019 Schau Bert

23/34

Antenna Lab

8x8 phased TSA array: geometry & mesh

0 0.1 0.2 0.30

0.1

0.2

0.3

0.4

0.5

0.6

m

m

12

34

567

8

8

16

64

48

56

40

32

24

704 triangles &

916 RWG modes

8/12/2019 Schau Bert

24/34

Antenna Lab

8x8 phased TSA array: 10:1 band VSWR

Broadside beam

45-deg diagonal plane scanning

8/12/2019 Schau Bert

25/34

Antenna Lab

8-by-Infinite Array Impedance

Active impedances for broadside scan

From Craeye,

Boryssenko and

Schaubert, ICAP 03

Infinite in H-plane

8/12/2019 Schau Bert

26/34

Antenna Lab

Self Admittances for 6x6 Array

Isolated Element

M t l Ad itt f 6 6 A

8/12/2019 Schau Bert

27/34

Antenna Lab

Mutual Admittance for 6x6 Array

Isolated Element

f S G

8/12/2019 Schau Bert

28/34

Antenna Lab

Radiation Patterns of Small Arrays - 0.8 GHz

Antenna Performance has not been optimized

R di ti P tt f S ll A 1 4 GH

8/12/2019 Schau Bert

29/34

Antenna Lab

Radiation Patterns of Small Arrays - 1.4 GHz

Antenna Performance has not been optimized

R di ti P tt f S ll A 2 0 GH

8/12/2019 Schau Bert

30/34

Antenna Lab

Radiation Patterns of Small Arrays - 2.0 GHz

Antenna Performance has not been optimized

V i ti ith O i R t

8/12/2019 Schau Bert

31/34

Antenna Lab

Variation with Opening Rate

r = 4 r = 1

eRaz

D=32 cm

Dsl=2 cm

Ra = 0.1, 0.2 0.3

V i ti ith A t D th

8/12/2019 Schau Bert

32/34

Antenna Lab

Variation with Antenna Depth

e0.1z

D=24, 32 40 cm

Dsl=2 cm

r = 4 r = 1

V i i i h C i Si

8/12/2019 Schau Bert

33/34

Antenna Lab

Variation with Cavity Size

e0.1z

D=40 cm

Dsl=1.5, 2, 2.5 cm

r = 4 r = 1

Summary

8/12/2019 Schau Bert

34/34

Antenna Lab

Summary

Can treat many cases of interest with existing

analysis / simulation tools

Large arrays extensively studied - reasonable level of

understanding

Small finite arrays - some study and understanding

Focal plane imaging behavior - very little study