as a type of noise that can corrupt the received signal.
Figure 7: Crosstalk can be caused by capacitive coupling of a voltage change or inductive coupling of a current change from the aggressor to the victim transmission line. (Image source: Amphenol)
Noise on a non-transmitting line can be received as a false signal. Noise can come from several sources, such as thermal noise, external radiation impinging on a transmission line, and noise from another line within the same device (crosstalk). Energy from these sources adds to the signals on a transmission line. Noise is characterized by the signal-to- noise ratio (SNR), which is the ratio of signal power to noise power on a transmission line. The higher the signal-to-noise ratio, the better the signal quality. Crosstalk Crosstalk is a subcategory of unwanted noise that appears on a transmission line due to interactions with electromagnetic (EM) fields originating from adjacent lines without direct contact. Crosstalk is caused by line-to- line capacitive or line-to-line inductive coupling between an aggressor (carrier) and a victim (receiver) line (Figure 7). Crosstalk is labeled according to where the victim experiences the coupled noise. Near-end crosstalk (NEXT) appears on the transmitter side of a transmission line or device under test (DUT),
Figure 8: Shown are examples of resonance effects due to transmission line stubs of several kinds with two different lengths on a 12 Gbps channel. (Image source: Amphenol)
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