Dennis Field / dvk-mx8m-bsb - History

Update the antennae footprints and feedline layout dimensions using the new stackup and relative permittivity given by the manufacturer, cut off the top corner of the speaker's pad #2 in order to make sure it does not hang off the top of the board

The GNSS CPW will likely be double checked by the manufacturer soon.

Complete the HDMI circuit routing (including the pull-down NFETs and the diff pairs going to them)

The diff pairs going to the NFETs are exactly matched to 0 with their phase/skew; 1V8P still needs to be brought to them.

Fence in the rest of the GNSS antenna area and fix the VBUS via array near the charge controller (now locked)

Routed signals I2C3_SDA, I2C3_SCL, IRQ_PROX, IRQ_IMU completey to the SOM.
To be fixed: Accidently moved vias near U301 (by dragging/shoving other signal).

Routing of CLK02 signal (among others) from ethernet PHY to SOM.
As this signal can carry a 25MHz square wave, a guard ring connected to GND was added.

Add stitching vias around the WiFi+BT antennae on the top-right section of the board, the vias form a fence-like structure and prevent interference in both directions

The rest of the path still needs to be stitched (around the GNSS antenna), and wrap around next to the earpiece speaker, which needed to be shifted slightly to the left. Once the proper via locations are determined between the speaker and the GNSS antenna area, the speaker can try to be placed as-close-as-possible to the horizontal-center of the board (at X=105mm).

Fit the new MHF4 footprint and antenna feedline together using the new footprint's dimensions

The MHF4 spec sheet gives dimensions for a 50Ohm CPW coming from it, however this feedline is actually a microstrip line and therefore it should follow our specific width requirements (using our relative permittivity and top-to-bottom spacing). The width of the feedline will need to be adjusted once the permittivity between the top and bottom layer with the inner layers being void is given/known (at ~3GHz).

Use MHF4 instead of U.FL connectors on the WiFi+BT antennae