2.4GHz Antenna Design? (For BT Speaker)

[ssashton]

You don't think this antenna design is worth using? Greater range would be good of course.

[ThomasDK]

[...]this was designed for, has a capacitor 5.6pF and inductor 1.8nH in the line which my CSR chip has a little SMD band pass filter. Are these doing the same thing?

No it's not the same, the L+C is for fine tuning the antenna impedance to 50 ohm at 2.4GHz. If you change the board geometry they need to be retuned. You will need a VNA or a Spectrum Analyzer with tracking generator to tune it.

Since you are intending to sell these, go for a pre-certified module with onboard antenna to make your life easier. You still need to pass EMC+RED (+FCC if you intend to sell in the US), but a certified module takes the Bluetooth specific part of the testing out of the equation.

[ssashton]

I found datasheet info on what those parts do - they are actually to bring the output of the chip to 50 ohm, rather than tuning the antenna impedance which is already designed to be 50 ohms. Apparently the output of the CD2430 chip used on the example PCB from TI has a differential high impedance output.

Full in here Page 27 CD2430