DAF27TZ02-DV006 — Wideband Antenna for RF Photonics Modules

Design, fabricate, and experimentally test a wideband antenna solution ready to be integrated with standard RF-photonics transceiver modules. The antenna module must satisfy two key requirements. First, they should be fully compatible with standard packaging assemblies of RF-photonic modules. Second, they must deliver stable and efficient performance across a broad frequency bandwidth. However, integrating antennas with RF-photonic modules presents a significant challenge due to the electrically small size of the antennas and the bandwidth limitations imposed by Chu’s limit. To address this challenge, innovative antenna designs are required. These solutions may incorporate passive and/or nonlinear materials or elements to counteract the dispersive behavior of the antenna and enable broadband radiation while remaining suitable for integration with RF-photonic modules. The final design should ensure seamless integration of the RF-photonic and antenna modules, enabling them to work synergistically with minimized size, weight, power, and cost (SWaP-C).

Given its inherent broadband capabilities, RF photonics is a promising technology for both civilian and military applications. It is employed in several platforms, including autonomous vehicles, UAVs, and mobile devices, to sense and navigate complex environments and detect and track mobile targets, among many other use-case scenarios. Current studies are establishing and advancing RF photonic technology for several applications. However, these advances, especially in the radio frequencies or lower millimeter-wave regime, are still based on bulky antenna solutions, preventing the realization of compact systems that can be easily accommodated in small platforms. Proposals are sought to provide innovative antenna solutions addressing the need for integration with commonly packaged RF photonic modules without impacting their operation bandwidth. The proposed efforts shall build upon the existing integration-friendly antenna solutions to develop a novel antenna technology amenable to integrating electrically small broadband RF-photonic modules. By the end of Phase I, a broadband antenna module compatible with RF-photonics should be numerically analyzed. Phase II should focus on a proof-of-concept experiment of the integrated broadband antenna module with a selected RF photonics system. Overall, this topic aims to advance RF photonics technology with integrated antennas to meet demanding requirements, such as large bandwidth, reduced size and weight, and low profile. Relevant metrics that the proposers should consider are an antenna solution fully compatible to be integrated with the standard packaging topologies of RF photonic modules, an antenna module with excellent performance in the high RF regime, and with a bandwidth beyond Chu's limit.

As this is a Direct-to-Phase II (D2P2) topic, no Phase I awards will be made. In the Phase I effort, a feasibility study and initial development of the proposed antenna solution will be carried out. This endeavor should involve the design of the antenna module. Comparison between the proposed and the simulation-backed-up performance metrics, including the level of integration and isolation, the operational bandwidth, return loss, and radiation efficiency, should be carried out. At the completion of this phase, a preliminary design of the antenna module, meeting the indicated metrics for the proof-of-concept experiment, will be demonstrated and reported.

The Phase II effort should begin by finalizing and completing the design for the proof-of-concept experiment started at the end of Phase I. The performer shall accomplish the fabrication and complete characterization of the designed antenna module, including integration with a selected RF photonic module. Characterization should include the frequency dependence of parameters such as radiation pattern, return loss, efficiency, group delay, and isolation. A comparison among the proposed, simulation-backed-up, and experimental metrics shall be reported, along with relevant analyses and discussion. This phase should conclude with the experimental verification of the prototype antenna.

The Phase III effort should focus on additional research and refinement of the antenna module designed and experimentally tested in Phases I and II. The design of the final antenna module should incorporate the update in the design procedures guided by the experimental results conducted in Phase II. Manufacturability specific to the Air Force Concept of Operations (CONOPS) and end-user requirements will be examined. The study and development of low-profile broadband antenna solutions that can be integrated with RF photonic modules can benefit numerous programs within the DOD and several applications in commercial markets.