Phased Array, FSS and Polarizer Design

The flexibility and benefits of active electronically scanned arrays (AESAs) has seen their use as high end antennas in applications like RADAR, surveillance and communication, increase dramatically in the last few years, both for terrestrial and airborne use. The design of these devices is challenging and the demands that the design places on a simulation tool is very high. CST has recently introduced new array design functionality which makes the design of phased arrays, and related planar devices like polarizers or frequency selective surfaces (FSSs), at both the cell and full array level substantially more efficient and powerful. 

This webinar will describe the full design flow of a Ku band satellite communications array for airborne use. The initial design of the low profile antenna elements will show one of the key benefits of the new functionality: the ability to optimize the cell geometry simultaneously for operation at multiple frequencies and multiple scan angles. The positioning of the antenna on the roof of an aircraft requires the design of an aerodynamic radome which must be considered as part of the radiating structure, both at the unit cell level and the full array level. A hybrid field coupling approach will be used to investigate the effect of coupling between the closely located transmit and receive arrays, as well as the effect of positioning of the arrays on the aircraft at various locations. The Complete Technology approach in CST STUDIO SUITE allows a variety of numerical methods to be used in tandem to perform the complete analysis: an FEM simulation is used to optimize the antenna at the unit cell level, a time domain approach is used for the full array analysis, while an asymptotic shooting bouncing ray (SBR) simulation is used to predict the installed performance of the array. 

The unit cell design principle also applies to the optimization of planar periodic structures like polarizers and FSSs as well. A broadband optimization of a polarizer to convert an incident plane between linear and circular polarization will be used to illustrate how such a device can be designed to support a range of incident angles. This is an important consideration when an FSS is intended to be a conformal part of a curved structure such as a radome.