CHELTONUHF and GPS SatCOM Antenna The 19-450 UHF and GPS SatCOM Antenna is a combined UHF satellite communications and Global Positioning System (GPS) antenna. The antenna is low profile in construction and intended for airborne applications. The UHF section provides essentially hemispherical satellite communications coverage. The GPS section provides nominal hemispherical coverage in the GPS L1 and L2 frequency bands to allow reception of microwave signals from a number of satellites. A variant of the 19-450, the 19-450N, offers alternative types of connector. The UHF section comprises two independent elements: • A circularly polarized turnstile antenna comprising a pair of quadrature connected broadband horizontal crossed dipoles, fed via a pair of Roberts baluns. The antenna is polarized Right Hand Circular (RHCP) according to IEEE definition. • A vertically polarized, reactively matched, broadband, folded monopole. Low angle (0° to 35° nominal) coverage is provided by the vertical element, and high angle (35° to 90° nominal) coverage is provided by the circularly polarized element. In this way, essentially full hemispheric coverage is achieved for satellite communications. Both elements are dc grounded to provide a degree of lightning protection. The GPS section is a stacked patch arrangement giving right-hand circularly polarised radiation. The 19-450 utilizes a one-piece vertical shell moulded under heat and pressure for high strength and resistance to moisture ingress. The horizontal element is contained within a circular fibreglass moulding, which is securely and permanently fitted to the vertical shell. An aluminium alloy base plate provides for fixing the antenna to the airframe. Careful design of internal ribs and base-to-shell load transfer ensures very high side loading acceptance. The GPS element is mounted rigidly on the top face of the antenna. The Chelton Centre, Fourth Avenue, Marlow, Buckinghamshire, SL7 1TF, UK T: +44 (0)1628 472072 E: [email protected] W:chelton.com Chelton Limited has a policy of continuous development and stress that the information provided is a guide only and does not constitute an offer or contract or part thereof. Whilst every effort is made to ensure the accuracy of the information contained in this Data Sheet, no responsibility can be accepted for any errors or omissions. The copyright of antenna designs and images is copyright protected and owned by Chelton Limited. ©Chelton Limited.

CHELTONUHF and GPS SatCOM Antenna ELECTRICAL Frequency 240 MHz - 400 MHz Gain Low Angle: Average within 2 dB of a quarter wave stub High Angle: +4.5 dBiC minimum (average full band) at zenith Polarisation Low Angle: Essentially vertical when mounted vertically High Angle: Predominantly RHCP at zenith Power Rating 200 W max High Angle: 2:0:1 max Isolation > 15 dBBetween Low and High Angle > 30 dBBetween High Angle and GPS Connectors Type Low Angle High Angle 19-450 TNC Type Female N Type Female 19-450N N Type Female N Type Female High MIL-STD-810D, Method 501.2, Procedures I Altitude and MIL-STD-810D,...