971436Compact GNSS Antenna Phase 2ClosedSmall Business Research InitiativeInnovate UKGlobal Navigation Satellite Systems (GNSS) are well established and applications are expected to increase in the foreseeable future. Applications include navigation and positioning for a very wide variety of vehicles, people and high-value commercial goods. However, systems such as GPS and Galileo operate at microwave frequencies around 1GHz where the wavelength of signals is about 30cm. An antenna is an essential component in any GNSS system. The antenna size should be comparable with the wavelength to work efficiently. Typically, a conventional GNSS receive antenna might measure around half a wavelength (15cm) which is too large for many applications such as man-worn or electronic tagging systems. Smaller GPS antennas are available, but have reduced sensitivity. Also, as alternative GNSS systems such as Galileo become available there is a need to work with services operating on multiple frequencies from a single antenna. The challenge is to make an affordable antenna with a small physical size and high sensitivity. This proposal is for a project to demonstrate a highly compact antenna for GNSS applications covering the 1176MHz (GPS L5/ Galileo E5a) to 1575MHz (L1/E1) frequency range. The project will be led by BAE Systems Applied Intelligence Laboratories (AI Labs) who have over 50 years experience in antenna design, navigation techniques and electromagnetic (EM) simulation. AI Labs develops technologies for BAE Systems product units (Military Air, Maritime and Land Systems) and so is well placed to bring a military systems perspective, environmental qualification and exploitation route to the GNSS solution. MoD is currently funding AI Labs to design both wideband antennas and body-worn antennas manufactured using conducting textiles. AI Labs will be supported by Liverpool University (LU) who are one of the leading Universities in the UK for innovative research into novel antennas, electronics and measurement techniques. This proposal is for a follow-on to the Phase 1 study in which we developed a highly-compact crossed dipole antenna design which receives circularly polarised waves across the required frequency bands (1176, 1227 and 1575MHz). The design is compatible with the target size of 50mm and may be used both for body-worn and vehicle mounted applications. The aim of Phase 2 is to demonstrate a prototype antenna. The work will comprise 3 phases: Optimise existing design, manufacture prototype units and evaluate the RF performance characteristics. The RF performance characteristics will be evaluated with the antenna isolated in free space, above a ground plane and installed on the DSTL "phantom" (a manikin representative of the human body). Measurements will be carried out in the AI Labs anechoic chamber and the LU reverberation chamber and techniques for manufacture. Recent research at LU has demonstrated a compact (50mm x 50mm x 2mm) antenna design which receives circular polarisation over the desired three frequency bands (1176, 1227 and 1575MHz) with low rejected power (VSWR<1.5). This design, which is described in this proposal and is subject to a patent application, achieves a performance close to that required by SBRI. However, Phase 1 will investigate further size reduction, use of alternative materials and sensitivity of the design to near by materials. Following Phase 1, a prototype antenna will be built and demonstrated in Phase 2 which is outlined in this proposal.