[Paper Review] Flexible Phased Array Sheets: A Techno-Economic Analysis

Oren S. Mizrahi, Austin Fikes+1 more|arXiv (Cornell University)|Feb 7, 2023

Energy Harvesting in Wireless Networks4 citations

TL;DR

This paper presents a techno-economic model for large-scale production of flexible phased array (FPA) sheets, demonstrating that per-square-meter costs can reach $88.75 under middle-tier scaling assumptions. The FPA integrates RFICs, flexible PCBs, and thin radiators to enable lightweight, low-cost, and deployable systems for space, communications, and wireless power transfer applications.

ABSTRACT

Phased arrays have enabled advances in communications, sensing, imaging, and wireless power transfer. In all these applications, large apertures enable higher power, higher data rates, higher resolution, and complex functionalities, but are elusive owing to a correspondingly large cost, mass, and physical size. Flexible phased arrays (FPAs) show potential in breaking this trade-off. Their thinness and extremely low mass allow FPAs to be folded, rolled, or otherwise compressed into smaller sizes, thus enabling new regimes of transport and entirely new applications currently not possible. Though a number laboratory prototypes of FPAs have been constructed, the economics of large-scale FPA production has yet to be explored. This paper presents a model FPA architecture and a cost model for producing it at large-scale. The estimate of the per-unit-area cost is bounded by a three-tiered approach. The cost model projects a "middle" estimate for FPA production at $89 per square meter. Estimates for aerial mass density and startup cost are also discussed. This cost model demonstrates that an FPA can be produced at an efficient price point and can potentially replace existing solutions for space, communications, and vehicular applications that demand lightweight, portability, and durability in extreme conditions.

Motivation & Objective

• To address the lack of techno-economic analysis for flexible phased arrays (FPAs) in large-scale production.
• To model the cost, mass, and startup investment for a scalable FPA architecture targeting space and extreme-environment applications.
• To evaluate the economic feasibility of FPAs relative to existing rigid phased array solutions in key markets.
• To project cost and mass density reductions through scaling and technological advancements.
• To demonstrate that FPAs can achieve cost and mass performance competitive with or superior to current rigid systems.

Proposed method

• Developed a three-tier cost model (current, middle, asymptotic) for FPA production based on four manufacturing layers: RFIC, flexible PCB, radiators, and assembly.
• Used realistic market assumptions for labor ($50/hour), electricity (8.05 ¢/kWh), and inflation (3.8%/year) to estimate production costs.
• Projected aerial mass density using material thicknesses and densities, with values ranging from 195.22 g/m² (current) to 77.71 g/m² (asymptotic).
• Calculated startup capital costs by normalizing facility capex to annual throughput, estimating $1M for a 10,000 m²/year production line.
• Evaluated cost sensitivity to design variables such as IC process (Si CMOS vs. GaAs), frequency, PCB layers, and protective coatings.
• Benchmarked FPA costs against existing rigid phased array transceivers, showing a ~75% cost reduction potential.

Figure 1: Center: Envisioning the ideal FPA: thin, low mass, durable, low cost, with integrated electronics. Outside, clockwise from the top right: (a) A wireless power transfer tile with photovoltaic concentrators on one side, a FPA in the middle, and 10GHz flexible patch antennas on the other side

Experimental results

Research questions

• RQ1 What is the projected per-unit-area cost of producing flexible phased arrays at scale, and how does it vary across different technology and scaling assumptions?
• RQ2 How does the aerial mass density of FPAs compare to current rigid phased arrays, and what are the implications for space and airborne applications?
• RQ3 What is the required initial capital investment (capex) to establish a high-volume FPA manufacturing facility?
• RQ4 How sensitive is the final cost to key design parameters such as operating frequency, IC process, and PCB layer count?
• RQ5 How does the FPA cost compare to existing rigid phased array solutions in terms of price per square meter and performance trade-offs?

Key findings

• The middle-tier cost projection for large-scale FPA production is $88.75 per square meter, significantly lower than the current-tier estimate of $566.21/m².
• The asymptotic cost projection reaches $45.37/m² under ideal scaling and technological advancements, indicating strong long-term cost reduction potential.
• Aerial mass density is projected between 195.22 g/m² (current tier) and 77.71 g/m² (asymptotic tier), representing a 50–90% reduction compared to rigid counterparts.
• A startup facility capable of producing 10,000 m² of FPA sheets annually requires an estimated $1 million in initial capital investment.
• Cost increases by 170% (to $239.50/m²) when switching from Si CMOS to GaAs ICs, highlighting the importance of process selection.
• Operating frequency has a strong nonlinear impact: at 40 GHz, total cost rises to $761.35/m² (a 758% increase), underscoring the cost challenges at higher frequencies.

Figure 2: FPA cost [$/m 2 ] at different projection tiers: (a) Current ($566.21/m 2 ), (b) Middle ($88.75/m 2 ), and (c) Asymptotic ($45.37/m 2 ).