Hello,
I am currently making a pet-tracking collar using an MKRGSM 1400, I'm looking for suggestions for what antenna to use when creating this project. I'm looking for something small and compact so that it fits on the collar, but is strong enough to pull location data. I hope this makes sense, pretty new to MKR GSM 
Stolem:
Hello,I am currently making a pet-tracking collar using an MKRGSM 1400, I'm looking for suggestions for what antenna to use when creating this project. I'm looking for something small and compact so that it fits on the collar, but is strong enough to pull location data. I hope this makes sense, pretty new to MKR GSM
Are asking about buying an antenna or are you wanting to build an antenna?
If you want to build, you need to start with the frequency in use and then investigate various designs for around that frequency? And you will need some appropriate test equipment as you progress.
Paul
Looking at buying!