IWR1443: Level meter application - technical questions

Hello,

1) the RF circulator is used to magnetically separate the Tx and Rx ports using a common antenna.  This is not how the FMCW transmit antenna, and separate receive antenna are connected to the FMCW radar integrated devices.  No, we do not have experience using a circulator for this.

2) the plating on the Rogers 4835 Lo Pro RF laminate immersion silver is used on the EVM.  Immersion gold, or Immersion tin are used for additional oxidation resistance.  The Rogers website has dicussions, along with board fabrication houses like Streamline Circuits.   On the Rogers website there are local Field Application engineers to discuss the application of the RF laminate, 4835 (EVM), 4830 (77Ghz automotive optimized), 3003 (test instruments - best performance).Since RF energy travels on the layer surface the plating affects the RF performance, along with the Coplanar waveguide, stripline, and surface layer grounding.

3) In the device datasheets, 4.3 pin Multiplexing, MCU_CLKOUT register EA60h is used to control pin N9 to output a specific signal.   You would also use the Technical Reference Manual  TRM   , in the discussion section for the APLL clock divider.  The APLL takes the 40Mhz crystal or external clock, and multiplies this to an internal clock rate.  Using the TRM chapter, you would determine the high rate clock.   Then to have a 40Mhz clock output, you would set the APLL divider for the desired clock rate.

4) Larger Phased Array systems, need to share a common RF Synthesizer ~19.25Ghz reference, this is called Cascade.  The AWR1243, xWR1443 have special applications for this.   The concept of large phased arrays needs to have RF Tx controls with different combined Tx operation.  The signals used are:

   FM_CW_SYNCIn(CLOCKIn) - 19.25Ghz external synthesizer input

   FM_CW_SYNCOut(CLOCKout) - master radar device 19.25Ghz synthesizer output

   SYNC_IN - Timing Generator start of frame external trigger

   SYNC_OUT - master radar device start of frame trigger output

   CLKP - an ac coupled 1.8v clock is sent to each radar device

   CLKM - resistor to GND

There are additional limitations for the number of simultaneous Tx outputs, and the power supply for the 1p3v_RF1, 1p3_RF2 for more than 2 Tx at a time.

5) please contact Vaibhav, we need to check if an NDA is needed to share the measurement setup diagram.  Typically for phase noise measurements you have

special software, OSC_CLKOUT - measures 40Mhz clock conditioner output

special software, MCU_CLKOUT - measure APLL divided clock output

in Satellite or Single Radar Sensor, you would use Continuous chirp mode, and an external Clock input, and have a measurement antenna, test equipment to measure the Tx output.   In Cascade use, there is both the FM_CW_SYNCOUT(CLOCKOUT) 19.25Ghz, and the Tx outputs, in Continuous chirp mode.

Please contact Vaibhav if characterization data is needed, this may require an NDA.

6) please contact Vaibhav, this requires a characterization test graph, it may require an NDA

The radar device datasheet on the RF characteristics, lists the published RF tested values.

Regards,

Joe Quintal

Hello,

1) related to circulators, we have not used them.   If the circulator had enough Tx to Rx isolation, I think the minimum is 15db, it would need to be tested.   You would have to modify or redesign an EVM with 1mm connectors.

3) in Table 3-3, section 3.2.4, and the example of the divider for the PMIC registers, you can divide down the APLL clock to get a power of 2 divider.   The PMIC does not require an external clock, you could use the PMIC clock for external clock.

Regards,

Joe Quintal