GPS World, February 2016

for the signal combining circuitry For analog combining schemes this is the resolution of the controlled attenuators and phase shifters used The results here attempt to characterize the relationship between the minimum expected performance and the component properties Results suggest that the choice of analog combining components should be chosen such that the phase and gain resolution are commensurate and such that resolution in one parameter is not rendered useless by a lack of resolution in the other These results may form useful guidelines when designing analog RF null steering antennas ACKNOWLEDGMENTS This article is based in part on the paper Analog and Digital Nulling Techniques for Multi Element Antennas in GNSS Receivers presented at ION GNSS 2015 the 28th International Technical Meeting of the Satellite Division of The Institute of Navigation held in Tampa Fla Sept 14 18 2015 MANUFACTURERS The equipment used in our study included an Agilent now Keysight Technologies www keysight com E8361A PNA network analyzer Antcom Corporation www antcom com 2DG1215A MNS 4 GPS L1 L2 antennas an Arduino LLC www arduino cc Arduino Uno microcontroller a MACOM www macom com MAPS 010143 4 bit digital phase shifter a Skyworks Solutions Inc www skyworksinc com SKY12347 362LF 6 bit digital attenuator and a Tallysman Wireless www tallysman com TW127 in line amplifier FURTHER READING Authors Conference Paper Analog and Digital Nulling Techniques for Multi Element Antennas in GNSS receivers by J T Curran M Bavaro and J Fortuny in Proceedings of ION GNSS 2015 the 28th International Technical Meeting of the Satellite Division of The Institute of Navigation Tampa Fla Sept 14 18 2015 pp 3249 3261 Adaptive GNSS Antennas for Interference Suppression Advances in the Theory and Implementation of GNSS Antenna Array Receivers by P Arribas C Closas M Fernández Prades M Cuntz M Meurer and A Konovaltsev Chapter 9 in Microwave and Millimeter Wave Circuits and Systems Emerging Design Technologies and Applications edited by A Georgiadis H Rogier L Roselli and P Arcioni and published by Wiley 2012 pp 227 273 Mitigation of Continuous and Pulsed Radio Interference with GNSS 68 GPS WORLD WWW GPSWORLD COM FEBRUARY 2016 Antenna Arrays by A Konovaltsev D S De Lorenzo A Hornbostel and P Enge in Proceedings of ION GNSS 2008 the 21st International Technical Meeting of the Satellite Division of The Institute of Navigation Savannah Ga Sept 16 19 2008 pp 2786 2795 Navigation Accuracy and Interference Rejection for an Adaptive GPS Antenna Array by D S De Lorenzo J Rife P Enge and D M Akos in Proceedings of ION GNSS 2006 the 19th International Technical Meeting of the Satellite Division of The Institute of Navigation Fort Worth Texas Sept 26 29 2006 pp 763 773 A Novel Interference Suppression Scheme for Global Navigation Satellite Systems Using Antenna Array by M G Amin and W Sun in IEEE Journal on Selected Areas in Communications Vol 23 No 5 May 2005 pp 999 1012 doi 101109 JSAC 2005845404 Wideband Cancellation of Interference in a GPS Receive Array by R L Fante and J Vaccaro in IEEE Transactions on Aerospace and Electronic Systems Vol 36 No 2 April 2000 pp 549 564 doi 101109 7845241 GNSS Antennas GNSS Antennas An Introduction to Bandwidth Gain Pattern Polarization and All That by G J K Moernaut and D Orban in GPS World Vol 20 No 2 February 2009 pp 42 48 Available on line http gpsworld com gnss systemreceiver designinnovation gnssantennas 8480 A Primer on GPS Antennas by R B Langley in GPS World Vol 9 No 7 July 1998 pp 50 54 Available on line http www2 unb ca gge Resources gpsworld july98 pdf JAMES T CURRAN received a B E in electrical and electronic engineering in 2006 and a Ph D in telecommunications in 2010 from the Department of Electrical Engineering University College Cork Ireland He worked as a senior research engineer with the Position Location and Navigation group at the University of Calgary between 2011 and 2013 and is currently a grant holder at the Joint Research Center JRC of the European Commission EC Ispra Italy His main research interests are signal processing information theory cryptography and softwaredefined radios SDRs for GNSS MICHELE BAVARO received his masters degree in computer science in 2003 from the University of Pisa Italy Shortly afterwards he started his work on SDR technologies applied to navigation First in Italy then in The Netherlands and in the United Kingdom he worked on several projects directly involved with the design manufacture integration and test of GNSS equipment and supporting customers in the development of their applications Today he is appointed as a grant holder at the EC JRC JOAQUIM FORTUNY GUASCH received the engineering degree in telecommunications from the Technical University of Catalonia Barcelona Spain in 1988 and the Dr Ing degree in electrical engineering from the Universität Karlsruhe Germany in 2001 Since 1993 he has been working for the EC JRC as a senior scientific officer He is the head of the European Microwave Signature Laboratory and leads the JRC research group on GNSS and wireless communications systems