AVCHD is High Definition, a DVD is Standard Definition
For true AVCHD quality on a disc, you need BluRay (which Premiere Elements will do, if you have a BluRay burner)
There IS a way to put "about" 20 minutes of HiDef on a BluRay, but it will NOT play in a DVD player, the disc will only play in a BluRay player
AVCHD to DVD http://forums.adobe.com/thread/862611
Elements and AVCHD http://forums.adobe.com/thread/947846
The Tutorial Links Page http://forums.adobe.com/thread/1275830 may also help
Plus
Premiere Elements FAQ List (2 pages of FAQ as of September 2013) http://forums.adobe.com/community/premiere_elements/premiere_elements_faq?view=all
Premiere Elements TIPS List (6 pages of Tips as of September 2013) http://forums.adobe.com/community/premiere_elements/premiere_elements_tips?view=all