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Kongens Lyngby, Denmark

Jensen B.S.,Cobham SATCOM | Jensen B.S.,Technical University of Denmark | Johansen T.K.,Technical University of Denmark | Zhurbenko V.,Technical University of Denmark
SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference Proceedings | Year: 2013

In this paper a 24 GHz integrated front-end transceiver for vital signs detection (VSD) radars is described. The heterodyne radar transceiver integrates LO buffering and quadrature splitting circuits, up- and down-conversion SSB mixers and two cascaded receiver LNA's. The chip has been manufactured in a 0.25 μm SiGe:C BiCMOS technology and its size is 1390 × 2690 μm2. The transmitter demonstrates a maximum output power at 24 GHz of approximately -30 dBm with an externally applied LO power of 3 dBm. The receiver demonstrates a peak gain of 13.3 dB at 22.15 GHz with >10 dB return loss. The power consumption of the entire transceiver is approximately 164 mW. © 2013 IEEE. Source

Low L.,MIRA Ltd. | Zhang H.,Cobham SATCOM | Rigelsford J.M.,University of Sheffield | Langley R.J.,University of Sheffield | Ruddle A.R.,MIRA Ltd.
IEEE Transactions on Electromagnetic Compatibility | Year: 2013

An automated, low-field disturbance probe positioning system for measuring 3-D electric field distributions inside vehicles or similar resonant environments is described. Correlations between measured and simulated electric field distributions for a simple rectangular cavity demonstrate that the probe positioner has little impact on the measured field levels. Comparisons between measurements and simulations for a real vehicle indicate that the predicted field population distributions are within the estimated uncertainties of the measurements. © 1964-2012 IEEE. Source

Smith T.,Cobham SATCOM | Gothelf U.,Cobham SATCOM | Kim O.S.,Technical University of Denmark | Breinbjerg O.,Technical University of Denmark
IEEE Antennas and Wireless Propagation Letters | Year: 2013

This letter documents the design, manufacturing, and testing of a single-layer dual-band circularly polarized reflectarray antenna for 19.7-20.2 and 29.5-30.0 GHz. The reflectarray is designed using the concentric dual split-loop element and the variable rotation technique that enables full 360° phase adjustment simultaneously in two separate frequency bands. The elements have been optimized to suppress cross-polar reflection. Thereafter, the element data is included in a design tool that computes the reflectarray layout and the associated radiation patterns. The reflectarray is composed of 80 × 80 elements printed on a 40 × 40-cm2 Rogers 5880 substrate. The antenna has been manufactured and measured at the DTU-ESA Spherical Near-Field Antenna Test Facility. The peak gain is 35.8 and 40.0 dBi at 20.0 and 29.8 GHz, respectively, and the aperture illumination efficiency is in the range of 53%-63% over the two frequency bands. © 2013 IEEE. Source

Smith T.,Cobham SATCOM | Smith T.,Technical University of Denmark | Gothelf U.,Technical University of Denmark | Kim O.S.,Cobham SATCOM | Breinbjerg O.,Cobham SATCOM
IEEE Transactions on Antennas and Propagation | Year: 2014

A shared aperture antenna for simultaneous operation at L- (1525 to 1661 MHz) and Ka-band (19.7 to 20.2 GHz and 29.5 to 30.0 GHz) is demonstrated. This stacked antenna consists of a Ka-band reflectarray antenna with a frequency selective surface (FSS) ground-plane above an L-band patch array antenna. The reflectarray is based on the concentric dual split-loop element backed by a concentric dual-loop FSS element. The reflectarray comprises 80 × 80 elements and it is printed on a 40 × 40 cm2 Rogers 5880 substrate, while the L-band antenna is a 2 × 2 patch array. The reflectarray antenna has been manufactured at the Technical University of Denmark (DTU) and measured at the DTU-ESA Spherical Near-Field Antenna Test Facility. The reflectarray provides a maximum directivity of 36.4 and 38.5 dBi at 20.0 and 29.8 GHz, respectively, and an aperture illumination efficiency in the two frequency bands up to 57% and 48%, respectively. There is very little degradation in the L-band patch array performance due to the reflectarray, and it provides a minimum directivity of 11.8 dBi over the L-band. © 1963-2012 IEEE. Source

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