GEM1305 RTK module with built-in antenna

    Overview

    GEM1305 is a high performance dual-band RTK module with build-in antenna, which is based on CYNOSURE series chipset. It supports BDS-3 signals, along with global civil navigation systems, including GPS, BDS, GLONASS, Galileo, QZSS, and SBAS.

    GEM1305

    If you are working in the field of UAV, you can refer to the following links:

    Features

    • Supports GPS, BDS, GLONASS, Galileo, QZSS, and SBAS
    • Integrated Real Time Kinematics (RTK)
    • State-of-the-art low power consumption design
    • Supports multi-band multi-system high precision raw data output, easy for 3rd party integration
    • The best cost-effective high precision GNSS positioning solution integrated with antenna
    • Compact size 55x55x15mm with high performance

    Specifications

    Antenna

    Item Specs
    Frequency Range(MHz) GPS/QZSS L1,L5, BDS B1,B2, GLONASS L1, GALILEO E1/E5a
    Polarization Right-hand circular
    Gain(dBi) 90° L1≥5.5 L2≥5 L5≥2.5
    Phase center error(mm) ≤±2.0
    Axial Ratio (dB) 90°≤3.0
    LNA Gain(dB) 38±2
    V.S.W.R ≤2.0
    Noise Figure (dB) ≤1.8
    DC Voltage (V) 5.0～5.5
    Current (mA) ≤80mA
    Impedance(Ω) 50
    Relative Humidity 95%
    Operating Temperature(℃) -40～+85
    Storage Temperature (℃) -55～+85
    Dimensions(mm) 55 x 55 x 13
    Weight (g) 50g

    GNSS

    Parameter Specifications
    Constellations BDS, GPS, QZSS, GLONASS, Galileo, NavIC, SBAS
    Channel 128 hardware channels
    Update rates 5Hz default, max up to 10Hz
    Position accuracy GNSS 1.0m CEP
    SBAS ＜1.0m CEP
    RTK 1.0 cm + 1 ppm (H)
    2.0 cm + 1 ppm (V)
    Velocity & Time accuracy GNSS 0.05 m/s CEP
    1PPS 20ns RMS
    TTFF Hot start 1s
    Cold start 27s
    RTK Convergence time <10s
    Reliability ＞99.9%
    Sensitivity Cold start -148 dBm
    Hot start -155 dBm
    Reacquisition -158 dBm
    Tracking & navigation -165 dBm
    Protocol NMEA-0183
    RTCM 2.X, RTCM 3.X
    Baudrate 230400 bps, by default
    Operating condition Main supply 4.75-5.25V
    Digital I/O supply 1.75V to 3.63V
    Backup supply 1.62V to 3.63V
    Power consumption Tracking GNSS 30 mA @ 3.3V
    Single system 18 mA @ 3.3V
    Standby Data backup 16 uA
    RTC 1.4 uA
    Serial interface UART 2
    SPI 2
    I2C 2
    Operating limit Velocity 515 m/s
    Altitude 18,000m
    Environmental conditions Operating temp. -40°C to +85°C
    Storage temp. -40°C to +90°C
    Humidity 95% RH

    [1] tested with a good external LNA [2] Supported upon request with special firmware

    Hardware

    GEM1305 Main

    GEM1305_PINOUT

    CON_0(J6): 1.25mm pitch 6P connector Pinout:

    • GND
    • NC
    • Rx0 of GNSS module
    • Tx0 of GNSS module
    • 5V, input,max current:200mA

    CON_1(J5): Pin header connector 2.54mm

    • GND
    • NC
    • Tx1 of GNSS module
    • Rx1 of GNSS module
    • 5V

    UART0 can be used for firmware upgrade, while UART1 cannot.

    Applications

    GEM1305 with Ardupilot GEM1305 with PX4

    Package list

    • GEM1305 receiver
    • USB-to-Serial test cable (CH340-based,Red:5V Black:GND Green:Tx White:Rx)
    • 6P 1.25mm cable

    Resources