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AD8367 matching for 434MHz

Question asked by VikW on Nov 5, 2013
Latest reply on Nov 5, 2013 by jdobler

Hello.

I'm using the AD8367 and the  AGC-Mode (MODE=0V) at 434MHz.
Unfortunately, I have problems with the matching at the input
(from 50Ohm to 200Ohm) and output (from 200Ohm to 50Ohm). The AD8367 always tends to oscillate and has losses.

I've read in this forum that you can use an 4:1 transformer (TC4-1) for matching at the input....that's what I'll try next. Nevertheless, at the moment I'm still using an LC-matching.

I've tried to extrapolate the values from Table 5 (datasheet - page 14 of 24 ; V_GAIN = 0,75V) to 434MHz.
Do you have more values from this table, especially for approximately 434MHz (XS_in, XP_in, XS_out and XP_out)?  =)

I have seen that in Figure 15 and 17 (datasheet - page 9 of 24) the Z_in and Z_out at V_GAIN = 0,5V can be estimated. The interesting thing is, that at 434MHz and V_GAIN = 0,5V the output has exactly 50Ohm. Now I have to choose an matching that fits best (V_GAIN = min to max = 0,05V to 0,95V).

Do you have a recommendetaion which components I should / could use for the matching (output and maybe input if the 4:1 transformer doesn't work better)?

Sincere regards,
Vik

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