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A flexible phased array system with low areal mass density

Abstract

Phased arrays are multiple antenna systems capable of forming and steering beams electronically using constructive and destructive interference between sources. They are employed extensively in radar and communication systems but are typically rigid, bulky and heavy, which limits their use in compact or portable devices and systems. Here, we report a scalable phased array system that is both lightweight and flexible. The array architecture consists of a self-monitoring complementary metal–oxide–semiconductor-based integrated circuit, which is responsible for generating multiple independent phase- and amplitude-controlled signal channels, combined with flexible and collapsible radiating structures. The modular platform, which can be collapsed, rolled and folded, is capable of operating standalone or as a subarray in a larger-scale flexible phased array system. To illustrate the capabilities of the approach, we created a 4 × 4 flexible phased array tile operating at 9.4–10.4 GHz, with a low areal mass density of 0.1 g cm−2. We also created a flexible phased array prototype that is powered by photovoltaic cells and intended for use in a wireless space-based solar power transfer array.

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Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.

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High-level description of the code created to drive the hardware is available from the corresponding author upon reasonable request.

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Competing interests

A.H., B.A. and F.B. are co-founders and shareholders of Auspion Inc., which is involved in wireless power transfer applications. A.S. is currently employed at Auspion Inc. Several patent applications that cover certain aspects of the design of the integrated circuit and flexible substrate have been filed.

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Acknowledgements

The authors acknowledge Caltech Space Solar Power Project and Northrop Grumman Corporation for partial support of the work.

Author information

A.H. conceived the idea of the flexible RF phased array. M.R.M.H., A.C.F., M.G.-K. and A.H. designed the flexible array and its electromagnetic components. M.R.M.H., A.C.F., M.G.-K., F.B., B.A. and A.S. performed the reported measurements of the system. B.A., F.B., M.G.-K., A.S. and A.H. designed and implemented the integrated circuit. M.D.K., E.L.W., P.E., N.V., E.E.G., C.L., F.R., S.P. and H.A.A. contributed to the design and implementation of the PV concentrators and cells. M.R.M.H., A.C.F., A.H. and M.G.-K. prepared the manuscript.

Competing interests

A.H., B.A. and F.B. are co-founders and shareholders of Auspion Inc., which is involved in wireless power transfer applications. A.S. is currently employed at Auspion Inc. Several patent applications that cover certain aspects of the design of the integrated circuit and flexible substrate have been filed.

Correspondence to Mohammed Reza M. Hashemi.

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Supplementary Figs. 1–18 and Supplementary Tables 1–5.

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Further reading

Fig. 1: Phased array system architecture and its capabilities.
Fig. 2: Photographs of the proof-of-concept active phased array.
Fig. 3: Flexible fractal inspired modified patch antenna.
Fig. 4: Power synthesis and control unit.
Fig. 5: Performance of the 4 × 4 FPA system prototype.
Fig. 6: Photographs of a 4 × 4 FPA tile integrated with PV solar cells and concentrators.