TRF7970A as the NFC reader

Umesh,

Are you putting the phone into card emulation mode?  The response that you see with the Galaxy S3 could be when the phone goes through its polling loop.  There is a time in the polling loop that it will go into passive target mode for ISO14443A in which case it would respond to the REQA/WUPA sent by the TRF7970A. 

In Android 4.4, a host based card emulation feature is enabled.  

https://developer.android.com/guide/topics/connectivity/nfc/hce.html  

Thanks Eddie. How do I put a phone into card emulation mode?

You need to write an Android application.  See the link I posted above.  Also, here is an example that Google put out.

http://developer.android.com/samples/CardEmulation/index.html

Thank you, I will give a try. Appreciate your help.

additionally - 

with my S4, i can see that even in screen lock mode the handset is switching between Type A and Type B and that the UID or PUPI is randomly generated, which means that we are able to activate and select the emulated tag with no problem, but now what is needed is Layer 4 communications to complete getting something back in that higher layer.

The DLP Design TRF7970A BoosterPack code is what i have been using. I have created two additions (hce.c and hce.h) to that project which I am still working on which include that HCE Application Select IDs that are given as examples in the Android SDK.

the point is i am not 100% sure that an Android app is really needed, since i was able to get that far with the handset, by doing nothing special.

We will post those up (hopefully in the coming week or so) so everyone can get access.

Thanks Josh. It will definitely help us and we probably can narrow it down.