Hi Mike,
We did a little step forward. Now DW1000 don’t lose the PLL but our clock is not yet as you suggest above, we are working on it. We are following your indications step by step, and we performed the trigger delayed test. The result is this:
What do you think about it? Our measure show about 300 ps of jitter. We are working to reduce it and to reduce the signal amplitude @ 1.8 V.
With the actual configuration we are trying to do some more measures for validating accuracy. Our setup is very simply: a tag is placed in front of an anchor at fixed distance and orientation, both placed at heigth of 30 cm from ground. Varying the distance (from 1 m to 2.5 m) and/or orientation we noticed that the anchor moves from LOS to NLOS and vice versa in a not clear manner (the NLOS threshold is the same as described in section 4.7 of the user manual). Obviouslly no obstacle are placed between anchor and tag. Moreover, at fixed distance and variable orientation we noticed that the time of flight changes with a variation up to 50 decawave ticks. All measures are very repeateble: placing the tag in the same orientation we get the same results as before (std dev about 8 decawave tick). For us, it’s too much to be explained with the antenna delay changing with orientation considering that we use an omnidirectional antenna.
Thanks,
Gianni