Electronic oscillators lie at the heart of virtually all microelectronic systems, generating the clock signals used in digital electronics and the precise frequencies that enable radio frequency (RF) sensors and communications. While an ideal oscillator provides a perfect signal at a single frequency, imperfections degrade the spectral purity of real-world components. Such impairments, broadly quantified as phase noise, ultimately limit the performance of many military radars and commercial 5G systems. The issue is becoming increasingly burdensome as the airways become more congested and defense needs evolve.
Today’s best microwave oscillators can achieve extraordinarily low phase noise, but the highest-performing technologies make large sacrifices in pursuit of performance. Trade-offs lead to oscillator modules with undesirable size, weight, power, and cost (SWaP-C), limited tunability, and high sensitivity to their surroundings, all of which limit their use in advanced defense systems.
The Generating RF with Photonic Oscillators for Low Noise (GRYPHON) program seeks to eliminate the shortcomings of today’s microwave oscillators by developing ultra-low-noise versions that are simultaneously compact, widely tunable, robust, and volume-manufacturable. To achieve its objectives, GRYPHON will employ emerging innovations in optical frequency division, integrated photonics, and non-linear optics.
Recent benchtop demonstrations using laser-based techniques have set world records in microwave phase noise. In parallel, ongoing innovation in the fields of integrated photonics and non-linear optics has enabled dramatic reductions in the size, weight, and power (SWaP) of key components needed to implement photonic oscillators. This includes chip-scale laser resonators with high quality factors and optical frequency combs.
“By implementing advances in photonic microwave generation with integrated photonics, we see a pathway to create a significant leap in microwave oscillator capability, while simultaneously realizing characteristics not found in today’s products: very low phase noise, compact form factor, ultra-wideband tuning, and environmental robustness,” says Gordon Keeler, DARPA MTO program manager. “Through GRYPHON, we hope to realize a major increase in capability for next-generation radar and communications systems.”
GRYPHON will explore innovative microwave sources using state-of-the-art microfabricated photonic components to achieve the target program metrics while creating a path to manufacturability. To accomplish the target objectives, the program will focus on two specific research areas. The first aims to develop a prototype that can be readily tested within an application and brought to maturation quickly. During the first phase of the program, research teams will prioritize achieving low phase noise and compact form factor, while tuning and robustness will be emphasized in later phases.
The second research area will prioritize understanding the fundamental limits of photonic microwave generation. Research teams will be asked to offer at least an order of magnitude leap in one of three target metrics: size, phase noise, or frequency span.
Interested proposers will have an opportunity to learn more about the Generating RF with Photonic Oscillators for Low Noise (GRYPHON) program during a virtual Proposers Day, which will be held on April 8, 2021, from 11:00 a.m. to 4:00 p.m. EDT. Advanced registration is required to attend. To learn more, please visit: https://beta.sam.gov/opp/970f3efd1ef94df4b14759e2c7c34c71/view?keywords=GRYPHON&sort=-relevance&index=&is_active=true&page=1&organization_id=300000412.
Additional information will be available in the forthcoming Broad Agency Announcement, which will publish to https://beta.sam.gov/.