Oct 10, 2018
11:27 AM
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Oct 10, 2018
11:27 AM
I was unable to modulate BGT transmitter in a true FMCW mode, a continuous triangular/sawtooth wave. I've looked at the output of PLL and it produces a single up chirp, then it turns off and 250 ms later it does another up chirp. I commented out BGT_DUTY_CYCLE in config.h, as Infineon engineer suggested but I'm still getting just a single ramp. How can I modify the code to put device in FMCW mode?
3 Replies
Oct 11, 2018
01:00 AM
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Oct 11, 2018
01:00 AM
Which pin did you use to look at the PLL output?
Aren't the 250 ms due to the FRAME_PERIOD_ms (also in config.h)?
Aren't the 250 ms due to the FRAME_PERIOD_ms (also in config.h)?
Oct 11, 2018
07:55 AM
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Oct 11, 2018
07:55 AM
radaruser wrote:
Which pin did you use to look at the PLL output?
Aren't the 250 ms due to the FRAME_PERIOD_ms (also in config.h)?
I looked at pins 4, 5 of BGT24MTR11, which is an output of PLL passed through loop filter.
I tried changing FRAME_PERIOD_ms to 50 from 250 and it was set to 50 ms but still this is too slow, I want that to be 0 ms between ramps, or as close to that value as possible. However, the more I learn about BGT IC, the more it appears it's incapable of running FMCW due to heat.
Oct 12, 2018
12:29 AM
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Oct 12, 2018
12:29 AM
Well I agree that a frame period of 50 ms is still too high compared to a chirp duration of 1,5 ms (or max 3 ms)...
Maybe anyone else has an idea?
Did you get the information about heat incapability from the BGTs datasheet?
Maybe anyone else has an idea?
Did you get the information about heat incapability from the BGTs datasheet?