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This paper addresses the integration of a reflectarray antenna (RA) on a thin film Solar Cell (SC) panel, as a mean to save real estate and cost in platforms such as satellites. The challenge is to design a good reflectarray cell in terms of phase and bandwidth, while simultaneously achieving high optical transparency and low microwave reflection loss, so as to preserve good SC and RA energy efficiencies, respectively. Since there is a tradeoff between the transparency and surface conductivity of a conductor, the choice of the conductive material to be used for the RA cell is an important design variable, in addition to all geometrical parameters optimized. The results obtained demonstrate the feasibility of an integrated RA on SC, preserving for the first time both SC and microwave performances. For instance, microwave loss of 1.15 dB and optical transparency of 92% using a TCO transparent conductor.

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In this work, we propose a novel technique based on neural networks, for the design of microwave filters in shielded printed technology. The technique uses radial basis function neural networks to represent the non linear relations between the quality factors and coupling coefficients, with the geometrical dimensions of the resonators. The radial basis function neural networks are employed for the first time in the design task of shielded printed filters, and permit a fast and precise operation with only a limited set of training data. Thanks to a new cascade configuration, a set of two neural networks provide the dimensions of the complete filter in a fast and accurate way. To improve the calculation of the geometrical dimensions, the neural networks can take as inputs both electrical parameters and physical dimensions computed by other neural networks. The neural network technique is combined with gradient based optimization methods to further improve the response of the filters. Results are presented to demonstrate the usefulness of the proposed technique for the design of practical microwave printed coupled line and hairpin filters.