RF Over Fiber Transceiver with Integrated Photonics and Ultra-Thin Glass Interposers

Current and next generation military aircraft are increasingly utilizing millimeter wave (mmW) frequencies for communications, radar, and electronic warfare.  An aircraft can have a significant number of antennas with a number of these being phased-arrays with multiple individual elements.  The signals from these antennas must be brought to central computing resources for signal processing and integration. Routing mmW signals from antennas to processing units is currently done with coaxial cables which, for these frequencies, are heavy, expensive, prone to failure, and suffer signal degradation. RF over fiber (RFoF), is a promising technology which uses fiber optics to transmit mmW signals between computing resources and antennas.  The result is substantial savings in weight and cost, improved reliability, increased bandwidth, and immunity to EM.  In the proposed project Mosaic Microsystems will work with Lockheed Martin Advanced Technology Laboratories (LM ATL) and the Air Force’s AIM Photonics Institute to investigate the feasibility of using Mosaic’s ultra-thin glass with through-glass via (TGV) technology to form the basis of an RF over fiber (RFoF) transceiver. LM ATL has developed a RFoF transceiver using a silicon integrated photonics circuit (PIC) from AIM Photonics. The transceiver currently uses a Si substrate (interposer) for the photonics circuit and an organic laminate substrate for RF signals, power, and control.  Mosaic will work with LM ATL to demonstrate the feasibility of using glass to replace the Si interposer. The fiber as well as a laser and PIC chip will be attached to the glass interposer.  Optical waveguides will be formed on the interposer either by direct laser writing or thin film deposition.  Mosaic will also investigate the feasibility of using glass to replace the PC card and combining both the PC card and the photonic interposer into a single ultra thin glass substrate for the ultimate in integration, providing further reduction SWAP-C.  LM ATL will be a subcontractor on the project and will provide the application expertise, design, and familiarity with the Department of Air Force (DAF) end user and customer.  In this project we will also work with AIM photonics on the manufacturability of the glass-based RFoF transceiver. There are a number of candidate platforms that could benefit from this glass-based RF over fiber (RFoF) solution including the C-130, F-16, F-22 and F35.  During the Phase I, LM with work with the internal platform organizations to identify potential transition opportunities.