LoRa 868/915MHz,DIP, Spring antenna, AH1G.312B

Further reading

• Antenna Gain Explained: dBi vs dBd, and Why Higher Is Not Always Better — Antenna gain is directionality, not amplification. dBi = dBd + 2.15, and every 3 dB of extra gain halves the coverage angle — which is why a 3 dBi omni usually beats a 9 dBi omni on a device whose orientation you cannot
• Sub-GHz ISM and SRD Frequency Bands by Region: 433 / 868 / 915 / 470 MHz — A region-by-region table of the license-free sub-GHz bands used by LoRa, ISM and SRD devices: 433 MHz (ITU Region 1 only), 868 MHz (Europe), 902-928 MHz (US), 470-510 MHz (China), 920 MHz (Japan), plus the LoRaWAN regional channel
• LoRa Antenna Frequency: 433 MHz vs 868 MHz vs 915 MHz vs 470 MHz — The choice is regulatory first and technical second: 868 MHz for Europe, 915 MHz for North America and Australia, 470 MHz for China, 433 MHz where ITU Region 1 permits it. Propagation differences inside 433-928 MHz are small compared with duty cycle and EIRP
• Antenna Efficiency, Radiation Pattern and Near Field: The Numbers That Decide Range — Efficiency, not gain, sets how far a link reaches. Total efficiency folds in mismatch loss, the radiation pattern shows where the power actually goes, and the 2D²/λ far-field boundary decides whether your range test measured anything