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I'm looking for a board mount (IC) solution that will take the differential output of something like ONET1191 @10GHz and convert it to 50 or even 75 Ohm single ended.

I've looked through various suppliers for:

  • Baluns (and other transformer solutions)
  • Differential Amplifiers
  • Receivers/Transceivers

However, I can not seem to find any modules with a pass band around 10GHz. I see tons and tons of ~6GHz modules (makes sense because 1080p60).

Alternatively, I could simply pass it out through 100 Ohm twinax and into a discrete RF amp that takes differential input (those do exist, but they are expensive!!!). I am hoping to avoid this, due to cost reasons.

Just throwing this out into the wind to catch some useful suggestions, thanks!

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The typical solution is just to terminate one half of the differential output and deliver the other half to the single-ended transmission line. Your device provides up to 700 mV peak-peak output, which is as high as you're likely to see in a logic buffer at this data rate.

If you need a buffer amplifier to maybe prevent damage to the more-expensive TIA chip due to being connected to an off-board circuit, you could look at something like On Semi's NBSG16 12 Gb/s buffer.

If you need more than 700 mV swing, you could look at something designed as an electro-optic modulator driver, for example Picosecond Pulse Labs (now Textronix) 5865 amplifier. This can do up to 8 V peak-peak output at 12.5 Gb/s.

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  • \$\begingroup\$ The only thing that makes me pause before utilizing the dummy termination scheme is that I don't know how long the line to RF mixer might be. The RF mixer has a fixed dBm window for the input. Thanks for your suggestions. \$\endgroup\$ – Steve Novakov May 13 '14 at 20:30
  • \$\begingroup\$ @SteveNovakov, 700 mV peak-peak is a pretty big signal for digital at 10 Gb/s. Also, your part is a limiting TIA. Are you sure you want to send a digital signal into an rf mixer? \$\endgroup\$ – The Photon May 13 '14 at 20:32
  • \$\begingroup\$ You could send the signal differentially to the vicinity of the mixer, then use the NBSG16 as a buffer and dummy terminate there. \$\endgroup\$ – The Photon May 13 '14 at 20:33
  • \$\begingroup\$ Yeah, I'll have to think about this. It will have to be on 1 PCB though. I've inherited a lower-frequency design that I have to now improve for 10GHz. I don't know that I will keep that exact limiting buffer, it was just an example. I could, for example, just terminate the fiber coupling diode and then just deal with a single ended signal to start with. \$\endgroup\$ – Steve Novakov May 13 '14 at 20:36
  • \$\begingroup\$ @SteveNovakov, without knowing about what kind of signal you're measuring (digital or rf at least), and what your overall goal is, I don't think I can help you any more than this. Also, 10 GHz or 10 Gb/s? \$\endgroup\$ – The Photon May 13 '14 at 20:45

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