USB connector for ATUSB production

[Werner Almesberger]

David Kuehling wrote:
> 
> BTW why use a discrete connector component, when you can turn the PCB
> into a USB connector (without shield).  Recently lots of (cheap) gadgets
> use that approach.

Yeah, I've used this elsewhere as well:
http://downloads.qi-hardware.com/people/werner/tmp/usbpcbconn.jpg

This is a nice approach, but it has a few issues as well:

- you need either a 2.0 mm (non-standard) PCB or add some material
  to increase the thickness,

- reduced mechanical stability and reduced ground connectivity (*),

- last but not least, going from a 0.8 mm PCB to a 1.6 mm PCB
  would require a redesign of the antenna and the RF feed line,
  followed by the full RF testing ritual.

  By using 0.8 mm PCBs for atben and atusb, both have very similar
  characteristics on the RF side.

(*) According to http://focus.ti.com/lit/an/swra117d/swra117d.pdf
    the more ground, the merrier the antenna.

- Werner