Numerical Synthesis Algorithms and Antenna Designs for Next Generation Spaceborne Wind Scatterometer and CubeSat Antennas
Two novel aperture type antennas, both for next-generation space borne applications, are designed. The first is 3D printed, all-dielectric, inhomogeneous, shaped lens antenna designed to produce a conically scanned spinning spot beam. The electronic scan stems from a ring of feeds located along the ring focus designed into the azimuthally symmetric lens. The antenna is proposed for use in a space-borne scatterometer used to measure wind speeds upon the surface of the earth’s oceans. The design requires the advent of a complex code hybridizing the Computational Electromagnetics method of Geometrical Optics with the optimization strategy of Particle Swarm Optimization. This code and its mathematical formulations, the resultant designs, and the measurements validating the codes and obtained designs are presented in this dissertation. The second is a new novel dual reflector Gregorian antenna system designed to meet the stringent requirements of the newly proposed CubeSat satellite paradigm by folding the optics into one of the most compact dual reflectors to date. The design combines a high gain reflectarray main aperture with an ellipsoidal subreflector fed by a patch array feed. The system is coplanar with the CubeSat chassis, deploying only the subreflector and thus has no moving cables or RF parts. This antenna design also requires a complex computer code to design. The code implemented to design the reflectarrays applies several novel acceleration strategies to the spectral domain method of moments algorithm in order to speed up the calculations. The theory and mathematical formulations behind this algorithm are also presented, as well as the resultant designs and measurements. The accelerated codes are used to design several Ka-Band reflectarrays. Measured and simulated results are provided.