Other Parts Discussed in Thread: CC1310
Hello!
Some time ago i asked for RF layout review for cc1310+cc1190 solution. Now i finally get my device and I'm trying to test maximum RF transmission distance.
I am sending simple packets from my device and receiving them with cc1310 launchpad in SmartRF Studio. Transmission is based on RfPacketTx example with the addition of amplifier control.
1. For 30 meters (through 2 floors) between receiver and transmitter:
Low Gain Mode (PA_EN high, HGM/LNA_EN low):
13:08:01.350 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -73
13:08:02.190 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -75
13:08:03.015 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -74
13:08:03.841 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -75
13:08:06.165 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -74
13:08:07.005 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -74
13:08:07.829 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -74
13:08:08.655 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -74
13:08:09.482 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -73
13:08:10.311 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -74
13:08:11.141 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -75
13:08:11.975 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -75
13:08:12.799 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -74
13:08:13.630 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -74
High Gain Mode (PA_EN/HGM high, LNA_EN low). I expected better RSSI level, but it remains same:
13:15:12.888 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -75
13:15:13.717 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -74
13:15:14.543 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -74
13:15:16.869 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -75
13:15:17.709 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -75
13:15:18.537 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -74
13:15:19.363 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -75
13:15:20.191 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -74
13:15:21.017 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -75
13:15:21.843 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -76
13:15:22.683 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -76
13:15:23.499 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -76
13:15:24.339 | 0d | 59959 | 39 33 31 32 34 35 33 34 31 34 2a | -76
2. The maximum distance at which packets are transmitted without errors also turned out to be the same (about 300 meters) for High and Low Gain modes.
I checked, that voltage level on PA_EN and HGM pins actually equals 3.3 volts.
The only difference between my design and CC1310-1190 launchpad is that i am using helical antenna.
I can’t understand why turning on the amplifier does not affect signal strength.
