RF signal ac coupling to an differential pair.
时间：04-08
整理：3721RD
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I am ac coupling an inverter output (the inverter output comes out as a square wave) into a differential pair. The differential pair is biased with a resistor and ideal voltage source (ordinary scheme)
When I test the inverter output alone without the differential pair connected, the pss gives me tones at the fundamental and the expected harmonics of a square wave.
However, when I ac couple it and measure the pss signal at the differential pair input, all the tones(fundamental and harmonics) are attenuated significantly. I'm using big RC's such as 100p and 1M, and believe the RC is high enough that it's not causing filtering.
What can be my problem?
Thank you.
When I test the inverter output alone without the differential pair connected, the pss gives me tones at the fundamental and the expected harmonics of a square wave.
However, when I ac couple it and measure the pss signal at the differential pair input, all the tones(fundamental and harmonics) are attenuated significantly. I'm using big RC's such as 100p and 1M, and believe the RC is high enough that it's not causing filtering.
What can be my problem?
Thank you.
When I read your post, I wonder if you ever thought about transmission line impedances or termination, because you
don't mention these parameters. It's also unclear how you connected the single ended inverter output to the differential
pair. Please clarify.