IWR1642BOOST: What happes after the processing model is changed from complex 2x to complex 1x in Radar Studio?

AR_baseband_appnote_v0p6.pdfHello Hitoshi,

The ADC, Digital Front End, are operated differently in real, complex2x, and complex1x .

There are two ADCs after the downconvert mixer, the Inphase is always used.  The Quadrature ADC is used also in complex modes.

The Digital Front End has several sections,  CIC decimate by 9, IQ correction, Stage 1 decimate by 2 stages, resampler, and the  stage 2 which contains the further decimation, and tuning (stage 2 is what is different for complex 1x and complex 2x).

I have included a description.   Related to Radar Studio, the Receiver FFT graph is different.

  Complex 1x we show the translated spectrum, 0 to Fs (complex rate).

  Complex 2x we show the shifted complex spectrum from -Fs/2 to Fs/2.

In detection applications for range and velocity, the Complex 1x is a good choice.

In cases where we need to detect range and velocity, and use negative frequency for interference detection.

Regards,

Joe Quintal