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Posts: 4
Registered: ‎08-05-2015

SI4463: Antenna Diversity for TX

Hello,

 

I'm setting up our software requirements for SI4463-Tranceivers with Antenna Diversity.

 

For RX things are clear - i think (Setting up MODEM_ANT_DIV_MODE, MODEM_ANT_DIV_CONTROL and GPIO_PIN_CFG).

 

But i thought, it would be a good solution to use the same Antenna for TX, witch RX Divesity-Algorithm evaluated best for RX under considuration, that the rf path in air is bidirectional ;-)

 

But ANT_DIV = RX_AUTO = "Non-RX state: ANTENNA_1_SW=1 and ANTENNA_2_SW = 0"

 

Is there a way to achive that "Non-RX state: ANTENNA_X_SW = leaved as in RX state" ??

 

Thanks

Benjamin 

Posts: 72
Registered: ‎02-18-2014

Re: SI4463: Antenna Diversity for TX

Hi Benjamin,

 

We have made some changes around here on the latest revision. On RevC2A/A2A there are new enumerations for MODEM_ANT_DIV_CONTROL property including ‘AUTO -> Non-RX state: ANTENNA_1_SW and ANTENNA_2_SW = Selected Antenna’, which is what you are looking for. For TX it will pick the antenna that was previously selected by the RX diversity algorithm.

 

Regards,

Attila

Silicon Labs

Posts: 4
Registered: ‎08-05-2015

Re: SI4463: Antenna Diversity for TX

Ok - but i'm not familar with your harware/Software Revision Concept.

 

We are using Parts printed with "44631B/Bxxx".

Are you speaking from Parts with "44632A/Cxxx" and "44632A/Axxx"

Can we do software-Updates? Or change chips to higher Revisions?

What about SW and HW up- and downwards compatibility?

especially SI4463(B) to SI4463-C

 

Regards

Benjamin

Posts: 72
Registered: ‎02-18-2014

Re: SI4463: Antenna Diversity for TX

Benjamin,

 

Your part is a B1B revision if labelled as 4463B on the top marking. The old revision of chips are Si4460/61/63/64 B1B, and the new revisions are Si4460/61/63 C2A, and Si4467/68 A2A. There have been some internal HW changes from B1B to C2A/A2A, therefore it is not possible to upgrade the chip to a higher revision by software. To confirm the chip revision you can use PART_INFO/FUNC_INFO commands; there is a knowledge base article about it (look for ‘Identify part number and chip FW’).

 

Note that there is an application note, AN897, to provide assistance for transitioning from B1B to C2A/A2A.

 

The C2A/A2A devices should be backward compatible with the previous product family.

 

Regards,

Attila

Silicon Labs

Posts: 72
Registered: ‎02-18-2014

Re: SI4463: Antenna Diversity for TX

Also, there is a knowledge base article called  'EZRadioPRO backward compatibility' that you may find useful.

 

Regards,

Attila

Silicon labs

Posts: 4
Registered: ‎08-05-2015

Re: SI4463: Antenna Diversity for TX

Going back to my inital queststion:

 

Datasheet REV1.2 of SI4463 says:

" The antenna with the strongest received signal is then used for the remainder of
that RX packet. The same antenna will also be used for the next corresponding TX packet." Chapter 8.5 page 45.

 

So this is only true for RevC2A/A2A?

 

Regards

Benjamin

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Posts: 4
Registered: ‎08-05-2015

Re: SI4463: Antenna Diversity for TX

additionally: The Datasheet refers to Devices Si4463-Bxx-FM only.

So this statement in the datasheet is wrong?