PFI-TT: Novel Designs and Manufacturing Process for High Performance Reflectionless Radio Frequency Filters at 40 GHz and Above

Associated Universities, Inc., Vienna VA

Investigators

Abstract

The broader impact/commercial potential of this Partnerships for Innovation - Technology Translation (PFI-TT) project stems from the increasing need to filter and clean up radio frequency signals. The number radio frequencies used and data bandwidth needs of wireless devices and systems have rapidly expanded in several commercial sectors (e.g., 5G/6G, autonomous vehicles, Internet of Things, satellite communications, defense, test and measurement equipment, etc.). To ensure that all of these high throughput data lanes remain interference free, devices must include better filtering to minimize the noise they broadcast. This filtering must be accomplished in a way that does not adversely impact size or cost. The proposed reflectionless bandpass filters aim to meet these requirements. The filters are being developed for high frequencies (28 GHz for 5G wireless communications for example) and offer a millimeter sized footprint that meets industry expectations for high reliability and low cost. The project aims to build on existing patents and industrial expertise to develop multi-stage, highly complex filter topologies, then perfect the manufacturing process to ensure that the devices meet both the performance and price expectations of commercial customers. Interest and feedback from the industry sectors charged with testing and certifying the current and future wireless devices indicates the potential for commercial success. The proposed project seeks to combine two state of the art technologies with proven track records, namely reflectionless radio frequency bandpass filters for signal-conditioning and Low Temperature Co-fired Ceramic (LTCC) based circuit board level components. The team seeks to quantifiably demonstrate that much higher frequency devices can be designed and manufactured in smaller and lower cost, maintaining the hermetically-sealed industry standard package types. These novel topologies and devices are increasingly necessary now that wireless communications and sensing devices are rapidly expanding into the already crowded frequency ranges above 20 GHz. The technology requires new, more complex layouts with multiple layers, as well as new LTCC manufacturing methods that yield reproducible and reliable results. While shown to work in theory, these higher complexity topologies require extensive computer modelling to ensure that the higher number of levels achieve the industry-provided target specifications and gains in performance. The LTCC manufacturing process will then have to be customized for the new layouts and materials and a small prototype run undertaken. The metrics for success will focus on achieving performance numbers (higher frequencies, high rejection, low insertion loss, etc.), reliability, manufacturing reproducibility, and yield. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.