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3 Attachment(s)
Just some silly links
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Nice links and information.
Is that your board, are you milling out the traces? I have not dealt with too much low frequency signals (< 30 MHz), but some of the questions I might have is in regards to trace impedance, and all border copper adding capacitance to the antenna line trace(s). From a quick look at some of the commercial boards, I noted that there is not much copper near the antenna signal line, and transmission line impedance is not a factor on the PCB, and will be tuned out. I could be wrong on this.
In my world, I deal more with differential pairs, and LVPECL interfaces. On my boards, differential pairs will maintain a transmission line impedance of 100 ohms (50 for LVPECL), and that the trace lengths are the same to one trace width. These are important especially at 100 MHz and up. Trace impedance control and consideration is always important on clock signals. I have seen ringing on lower frequency clock lines that will cause the attached phase lock loop output be at the wrong frequency - just because of impedance mismatch ringing.
If you look at the ATU-100 PCB, all the coils are in the center, and no ground copper nearby. Capacitors on one side, because the one side of the caps are at ground, which is probably running on the bottom side under the caps.
