Overcoming Variability in Printed RF: A Statistical Method to Designing for Unpredictable Dimensionality

摘要

As additively manufactured radio frequency (RF) design expands towards higher frequen-cies, performance becomes ever more sensitive to print-induced dimensional variations. These slightdeviations from design dimensions typically skew RF performance, resulting in low yields or poordevice performance. In order to overcome this limitation, RF design paradigms must be developedfor non-uniform process and material-specific variations. Therefore, a new generalized approach isdeveloped to explore variation-tolerant designs for printed RF structures. This method evaluatesthe feature fidelity and S11 performance of micro-dispensed, X-band (8– 12 GHz) patch antennas byevaluating the standard deviation in as-printed features, surface roughness, and thickness. It wasfound that the traditional designs based on optimal impedance matching values did not result in themost robust performance over multiple printing sessions. Rather, performance bounds determinedby print deviation could be utilized to improve large-batch S11 results by up to 7 dB. This workdemonstrates that establishing the average standard deviation of printed dimensions in any RFprinting system and following the formulated design procedure could greatly improve performanceover large datasets. As such, the method defined here can be applied to improve large-scale, printedRF yields and enable predictive performance metrics for any given printing method.