In AZ you must be personally served if you have a photo radar speeding ticket. However the courts in Tempe accept bad service. Process servers in your area will often times leave the service on your doorstep or sign a declaration that you were served. If this occurs the court will issue a failure to appear on your behalf even if you did not receive notice. A failure to appear on a traffic matter can lead to the court sending notice to DMV which will then result in a suspension of your driver's license.
Oftentimes courts only choose to offer traffic school before trial. Ignoring the ticket will not make this go away.