Tool/software:
Hello TI experts,
I am currently investigating the working principle of FMCW-TDM radar for speed and angle measurement using the TI IWR6843AOP.
I am currently unsure how it is even possible to compare the IQ phase (for lattre speed and angle measurement) over multiple chirps without a coherent output RF signal phase.
1. My assumption: For a single chip radar, the local oscillator phase (not the phase shifter phase) at the start of a chirp (after the idle time) is not the same angle over different chirps.
-> So no coherent output RF signal when comparing successive chirps.
2. My questions: Is a coherent output RF signal required at all over sequential chirps like in a pulse radar for e.g. coherent FFT Speed calculation?
My current assumption is that it is not required because the mixer in the receiver outputs the differential phase of the LO-Signal and received signal.
Thereby always outputs the absolute distance (phase) which can be used across multiple chirps and TDM Tx Antennas.
Is this correct?
Related to: IWR1443: How to Ensure the Phase Coherence of the Sampling Time Gate? - Sensors forum - Sensors - TI E2E support forums
Regards, Finn
