Laptop computers usually have the WiFi antenna in the upper border of the screen/cover. When you dismantle one down to the last bit, you end up with about 60 cm of coax, a super small coax plug connector and a J-pole looking antenna for 2.4 GHz (I haven't torn down a laptop with 5 GHz yet). There might/should actually be two antennas for reception diversity (improves signal quality).
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| Laptop computer WiFi antenna, coax and connector. |
Since these antennas work at 2.4 GHz, I wanted to know if that coax is any better than our HAM radio cables. Not an easy task without markings on the cable, but starting from the connector name, probably U.FL, I found a ready-made cable with detailed specifications.
Well, the manufacturer declares 3.2 dB/metre at 2.4 GHz. As a comparison, the "tiny" RG-174 we use in HAM radio, looses "only" ~2.4 dB/metre at 2.4 GHz.
Conclusion: unless you need a WiFi antenna for some homemade module (like ESP8266/ESP32) or a very tiny coax, these things are not a keeper.
