Other Parts Discussed in Thread: CC1190, WMBUS, CC1125
How is PA ramping enabled for use with FM packet transmissions? In RF studio, using the development kit with just the CC1120, it appears that only the PA_CFG2_RESERVED6 bit is changed when the PA ramping checkbox is selected. Selecting this on the development kit reduces the noise outside the occupied bandwidth found with packet transmission and peak detect on the spectrum analyser.
The first question is; should one ever use a reserved bit in a production item? The supplementary question is; why is it that the software engineer has found only one way to provide a continuous carrier, needed for some tests, and that is to set PA_CFG2_RESERVED6 to 1. He is sure that is the bit he uses, and that the CC1120 will only transmit a continuous carrier when the bit is set. How is it that RF Studio tells me this is the bit that is set to enable ramping?
The second is; how should ramping actually be enabled? The manual covers setting up the intermediate power levels and the ramp time as a proportion of symbol length, but not how to switch on the function.
The actual product uses the CC1120 with a CC1190, and the CC1120 is set to an output above which the power from the CC1190 does not increse significantly. Clearly there will be a different increase of carrier power as the ramp up approaches the compression point of the CC1190. Is there any recommended way to optimise this?
Thanks for any advice anyone can give
Andrew