Two PLL/VCO used for WCDMA RF circuit?
时间:04-04
整理:3721RD
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Hi all,
I have a question on FDD system such as WCDMA, in a given WCDMA RF circuit, are there two separate PLL/VCO parts which means one for Tx. and the other for Rx.?
I think it's true in FDD system such as WCDMA because FDD is full duplex system and the Tx. and Rx. circuits are working together all the time. Pls.kindly explain if there is something wrong in my mind, thank you very much!
I have a question on FDD system such as WCDMA, in a given WCDMA RF circuit, are there two separate PLL/VCO parts which means one for Tx. and the other for Rx.?
I think it's true in FDD system such as WCDMA because FDD is full duplex system and the Tx. and Rx. circuits are working together all the time. Pls.kindly explain if there is something wrong in my mind, thank you very much!
Yes, you are right.
Now in Qualcomm transceiver or CPU or Power ICs, there are sevral PLLs and VCOs for such uses.
You only need CLK input, and you can get IF from RF.
Generally speaking, Qualcomm adopts Zero-IF architecture.............