Ublox LISA-U1 Series System Integration Manual

Also see for LISA-U100: Integration manual

Contents

Ublox LISA-U1 Series System Integration Manual Manual pdf 102 page image

LISA-U1 series - System Integration Manual3G.G2-HW-10002-3 Preliminary Design-InPage 102 of 1252.4 Antenna guidelinesAntenna characteristics are essential for good functionality of the module. Antenna radiating performance hasdirect impact on the reliability of connections over the Air Interface. A bad termination of ANT can result in poorperformance of the module.The following parameters should be checked:Item RecommendationsImpedance 50 Ω nominal characteristic impedanceFrequency Range Depends on the LISA-U1 series module HW version and on the Mobile Network used.LISA-U100/U120:- GSM 850: 824..894 MHz = UMTS B5: 824..894 MHz- GSM 1900: 1850..1990 MHz = UMTS B2: 1850..1990 MHzLISA-U110/U130:- GSM 900: 880..960 MHz = UMTS B8: 880..960 MHz- GSM 1800: 1710..1880 MHz- UMTS B1: 1920..2170 MHzInput Power >2 W peakV.S.W.R <2:1 recommended, <3:1 acceptableReturn Loss S11<-10 dB recommended, S11<-6 dB acceptableGain <3 dBiTable 36: General recommendation for GSM antennaTo preserve the original u-blox FCC ID antenna gain shall remain below 3 dBi.Please note that some 2G and 3G bands are overlapping. This depends on worldwide band allocation fortelephony services, where different bands are deployed for different geographical regions.If the LISA-U110/U130 modules are planned for use on the entire supported bands, then a tri-band antenna(880..960 MHz, 1710..1880 MHz, 1920..2170 MHz) should be selected. If the LISA-U100/U120 modules areplanned for use on the entire supported bands, then a dual-band antenna (824..894 MHz, 1850..1990 MHz)should be selected. Otherwise, for fixed applications in specific geographical region, antenna requirements canbe relaxed for non-deployed frequency bands.GSM antennas are typically available as:Linear monopole: typical for fixed applications. The antenna extends mostly as a linear element with adimension comparable to lambda/4 of the lowest frequency of the operating band. Magnetic base may beavailable. Cable or direct RF connectors are common options. The integration normally requires thefulfillment of some minimum guidelines suggested by antenna manufacturerPatch-like antenna: better suited for integration in compact designs (e.g. mobile phone). These are mostlycustom designs where the exact definition of the PCB and product mechanical design is fundamental fortuning of antenna characteristicsFor integration observe these recommendations:Ensure 50 Ω antenna termination, minimize the V.S.W.R. or return loss, as this will optimize the electricalperformance of the module. See section 2.4.1Select antenna with best radiating performance. See section 2.4.2If a cable is used to connect the antenna radiating element to application board, select a short cable withminimum insertion loss. The higher the additional insertion loss due to low quality or long cable, the lowerthe connectivityFollow the recommendations of the antenna manufacturer for correct installation and deploymentDo not include antenna within closed metal case