CC1120 automatically change Bands from 169 to 950-MHz

[nxt_]

kindly i want to know is it available to change the communication bands for the CC1120 while it is in operation?

what i need to do in hardware to grantee that i can sweep from 169 to 950 MHZ?

thanks in advance

 

[FvM]

You need completely different matching networks and different antennas. Probably the best way to do it is to use two CC1120.

 

[nxt_]

Thanks for answer. but i am already using cc1120 what i am asking for is there is anyway to automatically set the bandwidth through the SPI with respect of the hardware. do i have to design a band pass filter after the antenna?.
thanks

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kindly could you please clarify why i would use 2 cc1120 to sweep the entire range?

 

[FvM]

What's your antenna solution to support both bands?

You need at least a RX balun and TX harmonic filtering. The TI suggested LC balun doesn't work for wideband, you may use a transformer. The TX filter and matching network must be switched between both bands, possibly togther with the antenna port.

My assumption is that separate transceiver can be the overall simpler solution, at least if you have two antenna ports.

 

[eriksen]

I would not recommend two transceivers for this as this would make the cost skyrocket. Instead use cc1120 and an antenna switch. Separate balun/matching network for the two frequencies.

However you use the term sweep. Do you mean that you want to sweep the whole area between 169mhz and 950mhz?

 

[vfone]

The price of CC120 is about $6, and an antenna switch is less than 50 cent.

There are baluns that works from 5MHz to 1GHz:
https://www.digikey.com/product-detail/en/C2139NLT/553-1672-1-ND/2498996

 

[FvM]

Yes, transformer balun and switched matching/filter network is a possible solution.

I didn't previouly pay attention to the "sweep" point. If you want to operate the transmitter at different bands than 170 and 915 MHz, you need to switch between more than two filters to comply with regulations.