1. SWAN™ - A fast and accurate CAD tool for slotted waveguide arrays

2. The software SWAN™: main features
Outline
Introduction
The software SWAN™: main features
Slotted waveguide antennas design examples:
Beam Steering Array
Low Side Lobe Fixed Beam Array
Traveling Wave Array
Shaped Beam Synthesis
Monopulse Antenna Design & Analysis
Arbitrary Subarray Geometry
Comparisons with CST MWS
Conclusions

3. Introduction Slotted waveguide arrays: - radar systems
Dielectric-filled
waveguides
0/2
Wide scanning angle in the plane x-y x y
Slotted waveguide arrays:
- radar systems
- communication systems
- mobile satellite terminals
- satellite broadcast/coverage
Footprint pattern
( Complex excitation is necessary )
Typical dimensions: hundreds of slots
Full-wave methods not suitable for design

4. Introduction
Design of large arrays made of hundreds or thousands of radiating elements
Computation unaffordable by any full-wave simulator
Simplified approach based on:
Equivalent circuit of the radiating element
extracted with an accurate full-wave analysis
Mutual couplings lumped in the model
using the “active impedance” concept
Fast and accurate analysis and design of large arrays
Final test with full-wave CST simulation is possible

5. The software SWAN™: main features
Outline
Introduction
The software SWAN™: main features
Slotted waveguide antennas design examples:
Beam Steering Array
Low Side Lobe Fixed Beam Array
Traveling Wave Array
Shaped Beam Synthesis
Monopulse Antenna Design & Analysis
Arbitrary Subarray Geometry
Comparisons with CST MWS
Conclusions

6. SWAN™ Software
SWAN™ is a new CAD tool for the design and analysis of large slotted waveguide arrays (thousands of slots). Its main features are:
User-friendly intuitive graphical interface
Customizable waveguide dimensions
Dielectric filling of the waveguides
Resonant and traveling wave slotted waveguide arrays
Mutual coupling and wedge diffraction effects considered
Dielectric and metal losses considered
Beam-scanning arrays analysis and design
Shaped beam synthesis (complex excitation coefficients)
Feeding network and input transitions can be considered

7. SWAN™ Software: Slot Model
Y(s,l,f)
Z(s,l,f)
l/0
s/a
Real(Y)
Imag(Y)
Imag(Z)
Wide band rigorous equivalent model, computed with a full-wave analysis in order to account for a number of details: dielectric filling of the waveguide, waveguide wall thickness, rounded edge of the slot, presence of a radome, etc.
Design and analysis make use of this equivalent circuit, rigorously taking into account slot mutual couplings by means of the active impedance concept.

8. Equivalent circuit of the slotted WG…
dshort
short circuit
Active slot admittance
Includes mutual coupling effects

9. The “Active Impedance” concept
Impedance matrix of the array
Self impedance
Mutual impedance
“Active” slot impedance:
Isolated slot
Mutual coupling term

10. Slotted waveguide array design Slotted waveguide array analysis
SWAN™ Software workflow
Antenna requirements
Slot model
extraction
SLOT MODULE
Slotted waveguide array design
DESIGN MODULE
Slotted waveguide array analysis
ANALYSIS MODULE

11. COMPUTATION PARAMETERS
SWAN™ Software: The GUI
Design Module
Analysis Module
DESIGN PARAMETERS
SLOT PARAMETERS
FEEDING CONFIGURATIONS
COMPUTATION PARAMETERS
EXPORT LAYOUT (DXF)
ANALYSIS PARAMETERS

12. SWAN™ – CST Integration
SLOT MODULE
SINGLE SLOT
CST SIMULATIONS
DESIGN MODULE
SLOT MODULE EXTRACTION
FINAL CST ANALYSIS
DXF EXPORT

13. The software SWAN™: main features
Outline
Introduction
The software SWAN™: main features
Slotted waveguide antennas design examples:
Beam Steering Array
Low Side Lobe Fixed Beam Array
Traveling Wave Array
Shaped Beam Synthesis
Monopulse Antenna Design & Analysis
Arbitrary Subarray Geometry
Comparisons with CST MWS
Conclusions

14. Beam Steering Slotted Waveguide Arrays for Ku-Band Satellite Communications
Ku-band slotted WG phased array
Ku-band slotted SIW phased array
Fast Design
&
Best Performance

15. Beam Steering Slotted Waveguide Arrays for Ku-Band Satellite Communications
Receiving slotted SIW array made of 32×32 slots, approx. size 40×80×3 cm
Received signal power spectrum from 11 to 12 GHz when the antenna is pointed at Eutelsat Hot Bird 13E

16. The software SWAN™: main features
Outline
Introduction
The software SWAN™: main features
Slotted waveguide antennas design examples:
Beam Steering Array
Low Side Lobe Fixed Beam Array
Traveling Wave Array
Shaped Beam Synthesis
Monopulse Antenna Design & Analysis
Arbitrary Subarray Geometry
Comparisons with CST MWS
Conclusions

17. Low Side Lobe Slotted Waveguide Arrays
X-band slotted wg array
SLRH=-28dB
-10 dB > 520 MHz
Accurate Synthesys
&
Short Time to Market

18. The software SWAN™: main features
Outline
Introduction
The software SWAN™: main features
Slotted waveguide antennas design examples:
Beam Steering Array
Low Side Lobe Fixed Beam Array
Traveling Wave Array
Shaped Beam Synthesis
Monopulse Antenna Design & Analysis
Arbitrary Subarray Geometry
Comparisons with CST MWS
Conclusions

19. Array for Radar Applications @ X-band
97.5 cm
25.4 cm
WG Matched Load
Array 10  36 traveling wave
f0 = 9.4 GHz
Taylor excitation
Ampl.
Phase 20 40 60 80
100
120
140
160
180
-60
-50
-40
-30
-20
-10 10 30
H-plane / degrees
Gain (dB) - f = 9.4 GHz
SWAN™ – CPU time ( 2.5 GHz )
Design = 48 sec
Analysis = 21 sec/freq. point
Fully Automated Optimization

20. The software SWAN™: main features
Outline
Introduction
The software SWAN™: main features
Slotted waveguide antennas design examples:
Beam Steering Array
Low Side Lobe Fixed Beam Array
Traveling Wave Array
Shaped Beam Synthesis
Monopulse Antenna Design & Analysis
Arbitrary Subarray Geometry
Comparisons with CST MWS
Conclusions

21. Large Arrays Beam Shaping (Complex Excitation)
12  24 slots planar array on WR90
H-plane: Cosec2 Pattern (90°  115°)
E-plane: Taylor Pattern SLR = -35 dB
SWAN™ – CPU time ( 2.5 GHz )
Design = 93 sec
Analysis = 15 sec/freq. point 5 10 15 20
0.2
0.4
0.6
0.8 1
Amplitude
-50 50
100
150
Phase
H-Plane excitation
9.1
9.2
9.3
9.4
9.5
9.6
9.7
-45
-40
-35
-30
-25
-20
-15
-10 -5
Frequency / GHz |S 1
| (dB) - all subarrays
= 470 MHz (5 %) 20 40 60 80
100
120
140
160
180
-60
-50
-40
-30
-20
-10 10 30
H-plane / degrees
Gain (dB) - f = GHz
Shaped beam in the H-Plane
E-plane / degrees
Low Side Lobes in the E-Plane
Satisfying your requirements

22. The software SWAN™: main features
Outline
Introduction
The software SWAN™: main features
Slotted waveguide antennas design examples:
Beam Steering Array
Low Side Lobe Fixed Beam Array
Traveling Wave Array
Shaped Beam Synthesis
Monopulse Antenna Design & Analysis
Arbitrary Subarray Geometry
Comparisons with CST MWS
Conclusions

23. Monopulse Antenna Key Elements
4-quadrant slotted waveguide array (SWAN)
Single quadrant waveguide BFN (SWAN)
Magic T (or hybrid coupler) (CST)
T-junction (CST)
Waveguide bends (CST)

24. BFN Schematic
Matched Load
Δel
A-C
B-D A B C D
A+C
B+D
Δaz Σ

25. Final Layout ΔH
Magic T ΔE Σ

26. Sigma

27. Delta E-plane

28. Delta H-plane

29. Design Example Using CST

30. The software SWAN™: main features
Outline
Introduction
The software SWAN™: main features
Slotted waveguide antennas design examples:
Beam Steering Array
Low Side Lobe Fixed Beam Array
Traveling Wave Array
Shaped Beam Synthesis
Monopulse Antenna Design & Analysis
Arbitrary Subarray Geometry
Comparisons with CST MWS
Conclusions

31. Arbitrary Subarray Geometry (1)
NEW FEATURE!

32. Arbitrary Subarray Geometry (2)

33. Arbitrary Subarray Geometry (3)

34. The software SWAN™: main features
Outline
Introduction
The software SWAN™: main features
Slotted waveguide antennas design examples:
Beam Steering Array
Low Side Lobe Fixed Beam Array
Traveling Wave Array
Shaped Beam Synthesis
Monopulse Antenna Design & Analysis
Arbitrary Subarray Geometry
Comparisons with CST MWS
Conclusions

35. Comparison with CST MWS (1)
Very good agreement with Full-Wave simulator CST MWS
SLRH=-28dB
-10 dB > 520 MHz

36. Comparison with CST MWS (2)
Cosec2 radiation pattern
16-slots linear array on WR90
SWAN™ 30 50 70 90
110
130
150
-60
-50
-40
-30
-20
-10 10 20
H-plane / Degrees
Directivity (dB) - f = GHz
8.6
8.8 9
9.2
9.4
9.6
9.8
10.2
-35
-25
-15 -5
Frequency / GHz |S 1
| (dB)
CST
-45dB
30°

37. Comparison with CST MWS (3)
18-slots linear array on WR90
Extremely low sidelobes (-35dB)
Beam shaping (deep nulls)
SLR=35dB
Deep null region
Deep null region

38. Comparison with CST MWS (4)

39. The software SWAN™: main features
Outline
Introduction
The software SWAN™: main features
Slotted waveguide antennas design examples:
Beam Steering Array
Low Side Lobe Fixed Beam Array
Traveling Wave Array
Shaped Beam Synthesis
Monopulse Antenna Design & Analysis
Arbitrary Subarray Geometry
Comparisons with CST MWS
Conclusions

40. Slotted Waveguide Arrays
SWAN™ - The best choice for
Slotted Waveguide Arrays
SWAN™ is fast, as it makes use of a rigorous equivalent circuit for the single slot obtained with an accurate full-wave analysis. The design and analysis of large arrays with thousands of slots can be easily carried out.
SWAN™ is accurate, as mutual coupling effects and their dependence on frequency and scanning angle as well as dielectric and metal losses are rigorously taken into account. Feeding network and input transitions can also be considered.
SWAN™ is flexible, as it allows for customizable waveguide dimensions, dielectric filling of the waveguides, many different feeding configurations, beam scanning optimizations, shaped beam synthesis, etc.

41. References
[1] R. Vincenti Gatti, R. Sorrentino, P. Mezzanotte, L. Roselli and F. Alimenti, “Accurate design of Ka-band flat scanning antennas for mobile satellite terminals,” 31st EuMC, European Microwave Conference, London, England, Sept
[2] R. Vincenti Gatti, R. Sorrentino, M. Dionigi, “Equivalent circuit of radiating longitudinal slots in dielectric filled rectangular waveguides obtained with FDTD method,” IEEE MTT-S, International Microwave Symposium, Seattle, Washington, USA, 2-7 June 2002, vol. 2, pp
[3] R. Vincenti Gatti, R. Sorrentino, “A Ka-band active scanning array for mobile satellite terminals using slotted waveguide technology,“ 25th ESA Antenna Workshop on Satellite Antenna Technology,
ESTEC, Noordwijk, The Netherlands, Sept
[4] R. Vincenti Gatti, R. Sorrentino, M. Dionigi, “Fast and accurate analysis of scanning slotted waveguide arrays,” 32nd EuMC, European Microwave Conference, Milan, Italy, Sept
[5] R. Sorrentino, R. Vincenti Gatti, “Design of low-cost flat-profile active scanning antennas for mobile satellite terminals in Ka-band,” Invited paper at MMS’2003, Mediterranean Microwave Symposium, Cairo, Egypt, 6-8 May 2003.
[6] R. Vincenti Gatti, R. Sorrentino, “Low-cost flat-profile active scanning antenna for mobile satellite terminals in Ka-band,” 3rd ESA Workshop on Millimetre Wave Technology and Applications, Espoo, Finland, May 2003.
[7] R. Vincenti Gatti, R. Sorrentino, M. Dionigi, “Low cost active scanning antenna for mobile satellite terminals,” IEEE AP-S, International Symposium on Antennas and Propagation 2003, Columbus, Ohio, USA, June 2003.
[8] R. Vincenti Gatti, L. Marcaccioli, R. Sorrentino, “A novel phase-only method for shaped beam synthesis and adaptive nulling,” 33rd EuMC, European Microwave Conference, Munich, Germany, 6-10 Oct
[9] L. Marcaccioli, R. Vincenti Gatti, R. Sorrentino, “Series expansion method for phase-only shaped beam synthesis and adaptive nulling,” URSI 2004, International Symposium on Electromagnetic Theory, Pisa, Italy, May 2004.
[10] R. Vincenti Gatti, R. Sorrentino, “Shaped beam synthesis method for slotted waveguide arrays,” MMS’2004, Mediterranean Microwave Symposium, Marseille, France, 1-3 June 2004.
[11] R. Vincenti Gatti, L. Marcaccioli, R. Sorrentino, “Design of slotted waveguide arrays with arbitrary complex slot voltage distribution,” IEEE AP-S, International Symposium on Antennas and Propagation 2004, Monterey, California, USA, Jun
[12] R. Sorrentino, R. Vincenti Gatti, “Slotted waveguide active phased arrays for mobile satellite terminals,” Invited paper at ISSSE 2004, International Symposium on Signals, Systems and Electronics, Linz, Austria, Aug
[13] R. Vincenti Gatti, R. Sorrentino, “A fast and accurate CAD tool for slotted waveguide arrays for radar applications,” 1st EuRAD, European Radar Conference, Amsterdam, The Netherlands, Oct
[14] R. Vincenti Gatti, R. Sorrentino, “Slotted waveguide antennas with arbitrary radiation pattern,” 34th EuMC, European Microwave Conference, Amsterdam, The Netherlands, Oct
[15] D. Trincia, L. Marcaccioli, R. Vincenti Gatti, R. Sorrentino, “Modified projection method for array pattern synthesis,” 34th EuMC, European Microwave Conference, Amsterdam, The Netherlands, Oct
[16] R. Vincenti Gatti, R. Sorrentino, “A fast and accurate CAD tool for slotted waveguide arrays,“ 28th ESA Antenna Workshop on Satellite Antenna Technology,
ESTEC, Noordwijk, The Netherlands, 31 May - 3 June 2005.
[17] R. Vincenti Gatti, R. Sorrentino, V. Schena, G. Losquadro, “Flat-profile active scanning antenna for satellite terminals in Ku-band operating on new fast trains generation,“ 28th ESA Antenna Workshop on Satellite Antenna Technology, ESTEC, Noordwijk, The Netherlands, 31 May - 3 June 2005.
[18] R. Sorrentino, R. Vincenti Gatti, “Slotted waveguide active phased arrays for mobile satellite terminals,” Invited paper at MRRS 2005, International Workshop on Microwaves, Radar and Remote Sensing, Kiev, Ukraine, Sept
[19] R. Vincenti Gatti, L. Marcaccioli, E. Sbarra and R. Sorrentino, “Flat Array Antennas for Ku-Band Mobile Satellite Terminals,” 30th ESA Antenna Workshop on Antennas for Earth Observation, Science, Telecommunications and Navigation Space Missions, ESA/ESTEC Noordwijk, The Netherlands, May 2008.
[20] R. Vincenti Gatti, R. Sorrentino, “A Fast and Accurate CAD Tool for Slotted Waveguide Arrays,” IEEE COMCAS 2009, Tel Aviv, Israel, 9-11 Nov
[21] R. Vincenti Gatti, L. Marcaccioli, E. Sbarra, R. Sorrentino, “Flat Array Antenna for Ku-band Mobile Satellite Terminals”, European Conference on Antennas and Propagation 2011, April 2011, Rome.
[22] R. Vincenti Gatti, S. Calzuola, R. Sorrentino, “Compact Short Circuit for Slotted Waveguide Array BFNs”, 41st EuMC, European Microwave Conference, Manchester, UK, 9-14 Oct
[23]

42. Slotted Waveguide ANtennas™
SWAN
Slotted Waveguide ANtennas™
ANALYSIS AND DESIGN
Copyright  Roberto Vincenti Gatti. All Rights Reserved.