In comparison to their single-ended frequency filter counterparts, differential filters are generally capable to maintain sufficient SNR, are characterized by lower total harmonic distortion (THD), feature high common-mode signal
rejection (CMRR), and furthermore with reduced input noise .
The device includes a unique common-mode regulation loop to regulate the common-mode signal
across the tank.
Alternatively, simpler structures based on etched defected ground structures (DGS) can be used to suppress the common-mode signal
These filters should be able to produce the desired differential-mode frequency responses and reduce the common-mode signal
interference at the same time, which is essential in increasing the signal-to-noise-ratio (SNR) in the receiver and improving the efficiency of the dipole antenna in the transmitter.
The ECG signal consists of three main components: the actual (differential) ECG signal, the differential electrode offset, and the common-mode signal
The center node is used for accessing the residual common-mode signal
and the undesired common-mode signal
Vcm = (Vin+) - (Vin-)
LCL is measured by applying a common-mode signal
to the cable.
If the ratio of the common-mode signal
to the differential signal present on the differential transmission line pair and the values for the differential and common-mode impedances are known, the amount of common-mode noise that will propagate through the differential interconnect can be estimated.
However, because each channel must handle the entire signal amplitude, small amounts of noise on top of a large common-mode signal
will be difficult to display.
Second, balanced signal lines have that extra dimension of freedom: the common-mode signal
An ADC's common-mode rejection ratio (CMRR) specifies how well it will reject a common-mode signal
in the presence of the differential signal you want the ADC to measure.