H200 DAOFENG Rubber high gain SMA-J ,2.4G WiFi antenna, AH2G.107

Further reading

• Impedance Matching and the Smith Chart: A Practical Guide for IoT Antenna Tuning — Matching moves the antenna's impedance to the 50 ohm centre of the Smith chart so power actually leaves the transmitter. In practice it is a loop: measure S11 with a VNA in the final enclosure, adjust the pi-network parts, re-measure — and expect the enclosure to be part of the
• VSWR, Return Loss and S11: What the Numbers Mean for an IoT Antenna — VSWR, return loss and S11 are three views of one defect — reflected power. VSWR 2.0 costs only 0.51 dB of mismatch loss, so the number that really matters is whether the antenna stays matched across the band in your enclosure, not whether it hits
• Wi-Fi Channel and Frequency Table: 2.4 GHz, 5 GHz, 6 GHz and Wi-Fi 7 — Centre frequencies and rules for every band Wi-Fi uses: 2.4 GHz channels 1-13 (only 1/6/11 are non-overlapping at 20 MHz), 5 GHz U-NII sub-bands with DFS, 6 GHz (Wi-Fi 6E) at 5925-7125 MHz, and Wi-Fi 7's 320 MHz
• External vs Internal Antenna: How to Choose for an IoT Device — Internal antennas win on cost, size and ruggedness; external antennas win on efficiency, bandwidth and placement freedom. The decision usually turns on three questions: is the enclosure metal, how much ground plane do you have, and can the device be oriented