nrf52832: Carrier Frequency

[Lukas Krupp]

Hello,

when transmitting packets with nRF52832 is there any chance to keep the carrier frequency off until the first bit of the preamble is being sent?

(The product specification implies that the carrier frequency is not on before the first bit, if the shortcut between READY and START is enabled (First picture without, second one with shortcut):

Nevertheless, I was able to measure the carrier approximately 15 us before the first bit is transmitted.)

Thank you in advance.

[ovrebekk]

Hi Lukas

Sorry for the slow reply. 

There is no way to remove this carrier, no. 

The PLL has to lock onto the reference clock at full output power, or the frequency would shift when the PA was turned on. The reception would also suffer, as the RX gets more time to adjust it's input gain when the carrier precedes the preamble.

If it's any consolation the carrier turned on even earlier in the nRF51 series (about 30-40us).  

Best regards
Torbjørn