Experimental Investigation of Origami Inspired Phased Arrays

Abstract

Origami (the art of folding) can be incorporated into antenna systems to provide compact size and low weight designs. Apart from this, the system can also provide physical reconfigurability and ease in deployment and portability. The antennas can be folded into and out of a particular shape. This will also provide a parameter in terms of folding to control the properties of the antenna system leading to a reduction in weight from external circuitry like actuators to control the antennas. But this is limited to the material constraints, complexity of design and electromagnetic performance.

Two antenna sub array systems based on origami are discussed in this thesis. The phased arrays are constructed using Microstrip patch elements and are folded based on the Miura Ori origami fold. The first is a linearly polarized 2x2 rectangular patch array operating at 2.45 GHz and the second is a circularly polarized 2x2 circular patch array operating at 3 GHz. An experimental analysis is carried out and their behavior in the intermediate folding states is studied.

From this experimental study, it is found that with the increase in the angle of folding the arrays, the impedance match becomes poor, the gain of the arrays decreases and the radiation pattern is distorted. This is due to the shielding effects of the ground plane and the decrease in the inter-element spacing. Some enabling technologies used in fabrication of origami inspired structures are 3D printing, Shape Memory Polymers and flexible conductors. Certain design considerations followed while designing a foldable array are minimizing the use of conductor on the folds.