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Electronics => Beginners => Topic started by: liyuqihxc on November 19, 2024, 01:13:43 pm

Title: what's the purpose of this microstrip track on a RF PA evaluation board?
Post by: liyuqihxc on November 19, 2024, 01:13:43 pm

I'm building a RF amplifier for CC1101 using PA2460.

There is an evaluation board layout in amplifier's datasheet.
https://www.princeton.com.tw/Portals/0/activeforums_Attach/PA2460.pdf (https://www.princeton.com.tw/Portals/0/activeforums_Attach/PA2460.pdf)

What I don't understand is the purpose of the following microstrip track (ML1), is it used as an inductor with C11 and C12 to form a pi filter? If so, can I replace it with an inductor?
[attachimg=2]
Here is the layout of the board
[attach=1]

Title: Re: what's the purpose of this microstrip track on a RF PA evaluation board?
Post by: CaptDon on November 19, 2024, 02:02:44 pm

Looks like a standard Pi impedance matching circuit. Not really a filter.

Title: Re: what's the purpose of this microstrip track on a RF PA evaluation board?
Post by: liyuqihxc on November 20, 2024, 09:27:36 am

thanks for the reply.
The reason I ask this question is that I want to know how to modify the design if I use a different board (like a 4-layer board). The evaluation board layout is on a 2-layer 1.2 mm FR4 board. Using components like inductors is clearly more flexible compared to a trace on the PCB.
The datasheet doesn't specify the frequency range for the reference layout, but the amplifier IC operates in the 130 MHz to 500 MHz band. The amplifier module I want to build operates at 433 MHz.

Title: Re: what's the purpose of this microstrip track on a RF PA evaluation board?
Post by: Neganur on November 20, 2024, 03:29:32 pm

impedance match to 50 ohm, the chip itself is not an mmic.