this could sound a repeated answer but to me it seems to be not so trivial. Or at least, it is so due to my ignorance.
I need to use an RF6886 power amplifier to interface it with a 50 ohm antenna. Are present the schematics of my frequency range (400-450MHz) and it is stated that it works pretty good with these 50 ohm.
With the PCB stackup used, 4 layers PCB, the RF traces are surrounded by GND planes on the LAyer 1 and the Layer 2 is a complete GND plane. Other signals/GND are on remaining planes. With this structure, the 50 ohm is achieved by a net of width around 0.65 mm (or less, now it is not importante the exact value). Here comes the problem: the reference schematic (in here, page 10) reports the component used, but I feel unconfidend on the physical parameters of the nets before the antenna connector, therefore everything that connects the components of the matching network. Moreover, the output uses all of 6 pins of one side. But unifying them in a large net, means having a much lower impedance (just as every other combination of this output). I could simply use the reference layout, but I didn't find it yet.
How can I extrapolate the allowed net characteristics (Width), while the only thing known is the maximum VSWR? The length should not be a problem (I suppose), being more more less than the wavelength. Not to mention the input: it is a sort of CLC T-network, but I'm totally unaware of the input impedance of the chip, so there is the same issue. I'm entering to it with a net of 50 ohms, but it is the only assumption that seems valid. I'm sure I am missing something.
A possible answer, for the OUTPUT only: In page 9 of that datasheet talks about load impedances of the reference schematic: assuming that it is the load saw just at the output pins, so before the matching network, I can extrapolate a net dimensions. But how about all the intermedium connections of the output network? (so...as just mentioned before)
I hope to be clear. Thanks and sorry if it is too silly.
