• State Verified Answer
  • +1 person also asked this people also asked this
  • Replies 6 replies
  • Subscribers 70 subscribers
  • Views 4030 views
  • Users 0 members are here
Attachments (0)
Nordic Case Info
  • Case ID: 234950
Options
This post is older than 2 years and might not be relevant anymore
More Info: Consider searching for newer posts

Thingy91 GPS sensitivity is horrible using the on board cellular antenna.

Hank Schraeder

The Thingy91 GPS system sensitivity is terrible.  Getting the GPS to lock on takes forever, and many times doesn't lock on at all, and if it does lock loses the connection regularly.  Sensitivity is 20 dB less than for a normal GPS receiver and is due to the RF front end using a cellular antenna instead of a normal circularly polarized antenna with zenith pattern. Luckily there is an external antenna port, I assume because Nordic engineers recognize the cell antenna solution is not going to work for most applications.  How about recommending a specific external antenna you know works well and comes with the highly unusual SMF connector on your board?

Parents
  • +1

    The Siretta MIKE3A, the Maxtena MEA-GPS-S or Tallysman TW4020 should all work. You'll need to use an adapter cable to connect the external antenna to the Thingy:91.

  • +1 in reply to Bjørn Kvaale

    For the community, there is no external GPS antenna I've found that will connect directly to the Murata MM8130-2600 connector on the board.  The required adaptor cable suggested by Nordic is MXHS83QE3000 with SMA female, Digikey part number 490-4982-ND, $30.78!!!!!.  The Maxtenna MEA-GPA-S is available from Newark UK stock for $17.54 and draws 6.6 mA current.  The Siretta MIKE3A is available from Digikey, part number MIKE3A/5M/SMAM/S/RA/17-ND, $13.74, current not specified.  The Tallysman TW4020 is available from Digikey part number 1526-1023-ND, $26.91, 12 mA current.  A great long term solution that requires special order, 4 week lead time is the Tallysman TW4029 with good out of band rejection and 1.75 mA typical current.  The concern is these antennas add a lot of gain to a circuit that already has a preamp of unknown gain.  May require an attenuator on the output of the external antenna so that the board mounted preamp is not overdriven into compression.

Reply
  • +1 in reply to Bjørn Kvaale

    For the community, there is no external GPS antenna I've found that will connect directly to the Murata MM8130-2600 connector on the board.  The required adaptor cable suggested by Nordic is MXHS83QE3000 with SMA female, Digikey part number 490-4982-ND, $30.78!!!!!.  The Maxtenna MEA-GPA-S is available from Newark UK stock for $17.54 and draws 6.6 mA current.  The Siretta MIKE3A is available from Digikey, part number MIKE3A/5M/SMAM/S/RA/17-ND, $13.74, current not specified.  The Tallysman TW4020 is available from Digikey part number 1526-1023-ND, $26.91, 12 mA current.  A great long term solution that requires special order, 4 week lead time is the Tallysman TW4029 with good out of band rejection and 1.75 mA typical current.  The concern is these antennas add a lot of gain to a circuit that already has a preamp of unknown gain.  May require an attenuator on the output of the external antenna so that the board mounted preamp is not overdriven into compression.

Children
Related