This section shows a snapshot of detailed simulations comparing diagonal jog and diamond jog via structures.
The following figure shows a detailed example of a diagonal jog breakout vs a diamond jog breakout. Differences between the breakouts were compared in two GND via proximity environments, densely populated proximity GND vias and sparsely populated proximity GND vias. Ideally, you would use dense proximity GND vias. However, device pin out could dictate the use of sparse proximity GND vias.
Broadly, the simulation results show either an equivalent or a net gain in all metrics for the diamond jog breakout. Dense proximity GND vias are marginally better than the sparse proximity GND vias. Layer 2 GND keep outs must be circular to minimize trace-to-trace crosstalk between the signal traces on layer 1 and layer 3. In addition under this structure, the GND keep outs must be on the lower layers a shown in the following example.
As shown in the following figure, in both GND via proximity environments (dense and sparse) the insertion losses for the diamond jog breakout and diagonal jog breakout were within a 1 dB range.
As shown in the following figure, in both GND via proximity environments (dense and sparse) the return losses for the diamond jog breakout and diagonal jog breakout were within a 1 dB range.
As shown in the following figure, in both GND via proximity environments (dense and sparse) the differential time domain reflections (TDR) impedance for the diamond jog breakout and diagonal jog breakout were within a 3Ω range. A TDR measures the reflections along a conductor.
As shown in the following figure, in both GND via proximity environments (dense and sparse) the diamond jog breakout is better than the diagonal jog breakout.
