As for antenna at 868 MHz you can go for a simple wire or a PCB track of 8.2 cm. This is a quarter wave at 868 MHz and will give good performance as long as the ground plane is of a certain size. Alternatively you can add a SMA connector an choose a antenna like the one we have in our demo kit. For small size PCBs like the Radiocrafts USB dongle you can go for chip antenna. Antennas at 868 MHz is available from many vendors since it is a ISM lisence fre frequency similar to 2.4 GHz.
Last Update: October 5, 2017