SWAN™ - A fast and accurate CAD tool for slotted waveguide arrays www.swan-soft.com

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

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

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

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

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

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.

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

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

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

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

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

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

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

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

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

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

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

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 ( P4 @ 2.5 GHz ) Design = 48 sec Analysis = 21 sec/freq. point Fully Automated Optimization

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

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 ( P4 @ 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 BW@-10dB = 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 = 9.375 GHz Shaped beam in the H-Plane E-plane / degrees Low Side Lobes in the E-Plane Satisfying your requirements

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

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)

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

Final Layout ΔH Magic T ΔE Σ

Sigma

Delta E-plane

Delta H-plane

Design Example Using CST

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

Arbitrary Subarray Geometry (1) NEW FEATURE!

Arbitrary Subarray Geometry (2)

Arbitrary Subarray Geometry (3)

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

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

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 = 9.375 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°

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

Comparison with CST MWS (4)

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

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.

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, 23-27 Sept. 2001. [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. 871-874. [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, 18-20 Sept. 2002. [4] R. Vincenti Gatti, R. Sorrentino, M. Dionigi, “Fast and accurate analysis of scanning slotted waveguide arrays,” 32nd EuMC, European Microwave Conference, Milan, Italy, 23-27 Sept. 2002. [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, 21-23 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, 22-27 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. 2003. [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, 23-27 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, 20-26 Jun. 2004. [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, 10-13 Aug. 2004. [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, 11-15 Oct. 2004. [14] R. Vincenti Gatti, R. Sorrentino, “Slotted waveguide antennas with arbitrary radiation pattern,” 34th EuMC, European Microwave Conference, Amsterdam, The Netherlands, 11-15 Oct. 2004. [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, 11-15 Oct. 2004. [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, 19-21 Sept. 2005. [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, 27-30 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. 2009. [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, 11-15 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. 2011. [23] www.swan-soft.com

Slotted Waveguide ANtennas™ SWAN Slotted Waveguide ANtennas™ ANALYSIS AND DESIGN www.swan-soft.com Copyright  2012 Roberto Vincenti Gatti. All Rights Reserved.