Slotted waveguide antennas
Slotted waveguide arrays find wide application in radar and communication systems and have nowadays become a promising candidate for scanning antennas in multimedia satellite communication systems.
Since typical dimensions of such antennas are of the order of hundreds of radiating elements, the full-wave analysis methods today available, though computationally very efficient, cannot bear the effort of simulating the electromagnetic behaviour of the whole antenna.
The software SWAN™ is a powerful CAD tool for the design and analysis of very large slotted waveguide arrays having a wide range of capabilities: fixed or scanning beam, very low side lobe patterns, shaped beams such as cosecant or flat top patterns, etc.
SWAN™ characteristics and performances
- 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 internal and external 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, weighted aperture synthesis, etc. The software may be therefore useful in many applications.
- The software presents a user-friendly and intuitive graphical interface.
- Waveguide properties (height, width, wall thickness and metal conductivity) as well as dielectric filling the waveguides (dielectric constant and tangent delta) can be arbitrarily defined.
- Internal and external mutual coupling and wedge diffraction effects are rigorously taken into account.
- Higher-order mode coupling between inclined coupling slots and radiating slots are automatically compensated.
- Resonant and travelling-wave slotted waveguide arrays as well as beam-scanning arrays design and analysis are possible.
- Feeding network and input transitions can be considered: a number of BFN models are implemented in the analysis, including mono-pulse comparators and T-junction-based BFNs.
- Waveguide Beam Forming Network made of inclined slots is automatically synthesized. A number of parameters can be modified, such as the number of sections of the BFN, the input impedance, etc.
- Subarrays can be divided into an arbitrary number of sections and each section can be enabled or disabled in order to create arbitrarily placed holes in the radiating aperture.
- The presence of flares or baffles beside the slotted waveguide array can be accounted in the design and analysis.
- The assumption of periodic boundary conditions is possible both in the analysis and design (the array is modelled as an infinite periodic structure).
- Complete arbitrary geometry definition is possible. Each section can have arbitrary number of slots and feeding point can be placed anywhere inside the section. The definition of feeding waveguide sections with arbitrary geometry and input feeding points is also possible.
- Layout of the whole antenna, including the waveguide BFN, is automatically generated in DXF format. The layout is ready-to-be-fabricated, and needs no further post processing. Machining radius parameter is also included in the export function.
- Arbitrary shaped beams can be synthesized either by providing the complex excitations or by providing the radiation pattern masks. A powerful optimization tool based on two alternative optimization methods automatically evaluates the optimum complex excitation to fulfill the requirements on the radiation pattern.
- Short-circuit septum thickness in multi-section radiating waveguides is automatically compensated by proper detuning of all slots in order to restore the best matching and the desired slot voltage distribution.
- The radiating layer can be covered by a dielectric layer (e.g. Kapton) or a dielectric multilayer.
- Montecarlo analyses can be performed on several geometrical parameters, such as slot offset, length, width, thickness, waveguide width and height.