A Study of Geometry and Commercial Off-The-Shelf (COTS) Antennas for Controlled Reception Pattern Antenna (CRPA) Arrays

摘要

Controlled Reception Pattern Antenna array (CRPA) is aneffective approach for rejecting interference andenhancing the received GNSS signal power.Conventionally, the antenna array used for CRPA isdesigned for reducing imbalance between elements.Additionally, full calibration should be made forcalculating the spacing between elements and the cablinglatency before performing CRPA. Hence, the high costand complex calibration of antenna arrays decrease theattractiveness of CRPA to many user communities. Wedevelop an approach which can perform CRPA withoutany prior information. Specifically, inexpensive andCommercial Off-The-Shelf (COTS) antennas can be usedas elements of an antenna array. This allows the elementsto be easily arranged to any desired array layout. Withthis new freedom in array geometry, the important issueof its effect on performance is raised. As thecharacteristics of antenna and array layout will affect theanti-interference performance, it is important to study theeffect of antenna array geometry and select the bestunits/layouts combination.In this study, we examined both COTS antenna use andthe effect of array geometry by assessing three models ofcommercial antennas and arranging these in two selectedlayouts. The antenna patterns of two physical layouts areanalyzed in terms of beamwidth and illustrated. Signalcollection hardware is built to record the data sets ofantenna array. A positioning procedure of calculatingelectrical layout is developed using differential carrierphase measurements. We collected data sets for eachantenna/layout combination. And, these data sets areprocessed by our software receiver to log the carrier phasemeasurements. The electrical layouts determined from thepositioning procedure are compared with physical onesfor examining the mutual coupling effects on the antennaarray. From these results, we can assess the array layoutsand the COTS antennas