IWR1443: IWR vs AWR

Hi there, 

I have just found out about the AWR and IWR sensors in a week or so and I am doing some comparison between AWR1443, AWR1642, IWR1642 and IWR1442. 

However. I cannot understand what is the deference in these sensors such that the price differs of approximately $100 between AWR and IWR sensors. 

Are there any production plans for any of these sensors?

Thanks,

Joseph