CC1101 transmit unmodulated signals

CC1101 can send unmodulated signals. If you use SmartRF Studio and go to the "continuous TX" and tick the box for "unmodulated" the CC1101 will be set up to send unmodulated signals. The registers you need to set in your software will be highlighted when you tick the box.

If the "unmodulated" continuous wave mode is used, are any external inputs required? 

Or is sending the STX command strobe in this mode suffice to "turn on" the signal?

choosing the unmodulated signal is sufficient to "turn on " the signal, you will not need external inputs then. For moudlated signal without external inputs, choose modulated signal and random data.

hello, I have a question , after ticking the "unmodulated", the unmodulated signals are the unmodulated carrier signals  or the date basic signal? thanks! 

Unmodulated signal is sending a CW at the programmed frequency.

Thanks, is it  a pure sine wave? if the chip is CC2530, can it also send the unmodulated carrier waves?

A CW is a pure sine. All our radio chips are able to send a CW. Use SmartRF Studio to find out which registers that needs to be set.