CC1111 Stated Frequency Range Error?

Are you using one of our EM boards?  If so, the filter network on the RF signals going to the antenna do not operate down to the minimum frequency of the part.  You will need to change these component values in order to see any signals from the antenna at these frequencies.

Jim Noxon

Hi Jim; thanks for the reply. I am using something very similar to the data sheet reference design for 868/915 MHz to match a 50 Ohm connector. But this is not the explanation. There is a very abrupt change in RSSI output near 835 MHz. If I input a swept signal from 780 - 930 MHz at -40 dBm into the RF connector, I see essentially noise floor in the RSSI up until near 830 MHz. Then I very briefly see something noise-like. Then suddenly at near 835 MHz on up through 928 MHz I see a strong -40 dBm RSSI (within +/- 1 dB).  Matching circuit error would not produce such an abrupt change.

I seem to remember a similar isue to this once before.  I'll have to do some digging and get back to you.

Jim Noxon

Are you sure the PLL is in lock and that you are operating at the right frequency? Easy test is to program TX at 835 MHz and check if you get a carrier at that frequency.

Make sure you set FSCAL2 = 0x2A and TEST0 = 0x0B when operating at 835 MHz.