Multi Coil Quadrature Demodulation Signal Chains for Proximity Measurement
Multi coil quadrature demodulation isolates amplitude and phase in inductive proximity chains, resolving sub-micron targets while rejecting thermal noise.
Trace Balance
Symmetric Routing
The matching of physical dimensions and trace lengths between a pair of conductor lines on a printed circuit board preserves signal symmetry. This trace balance is essential for differential signaling, where equal and opposite voltages carry high-speed digital data or low-amplitude analog sensor signals. Any asymmetry in the traces converts common-mode noise into differential noise, distorting the signal and generating unwanted electromagnetic interference.
It maintains the electrical equilibrium of the signal path.
Crosstalk Protection
Symmetric traces ensure that external noise from neighboring power rails or switching lines affects both lines equally. Because the receiving amplifier measures only the difference between the two signals, this noise is rejected. This balance allows high-speed communication lines to run through crowded boards without picking up interference.
Differential Impedance
Variations in trace width or separation distance alter the characteristic impedance of the pair along its length. These impedance discontinuities cause signal reflections that degrade data integrity and cause transmission errors. Precision PCB fabrication methods are used to control trace geometry and spacing.
Validation Measurement
Designers verify the trace symmetry using time-domain reflectometry or network analyzers to measure the differential return loss. These instruments inject a fast pulse and monitor the reflected waves to locate any electrical imbalances. This measurement confirms the board’s high-frequency performance.