Coming by airplane
Frankfurt/Main is the most convenient airport. Express trains (ICE/IC) depart about 200m away from Terminal 1 (follow signs “Fernbahnhof/Long-distance Station”). From there take a train to Karlsruhe Hauptbahnhof (Main Station). One way takes around 1 hour and costs around 40 EUR. Cheaper connections depart from the basement of the airport (follow signs "Regionalbahnhof/Regional Station", travel time around 2 hours, about 30 EUR). Check timetables and fares for all trains on www.bahn.de/en ».
Actual information: There is currently construction work on the railway line. Therefore, there are often rail replacement buses on the first part of the route. 

Ettlingen is 8 km away from Karlsruhe Station and can be reached by tram line "S1 Ettlingen", tram stop "Ettlingen Stadt", around 4 EUR, or by taxi (approx. 30 EUR) within 15 minutes. You can book a ticket valid from Frankfurt Airport to "Ettlingen Stadt", so it's not necessary to buy a separate tram-ticket in Karlsruhe. 

Coming by train
Get off at Karlsruhe Hauptbahnhof, (Main Station). Ettlingen is 8 km away from Karlsruhe station and can be reached within 15 minutes either by taxi (approx. 30 EUR) or tram (line "S1 Ettlingen", tram stop "Ettlingen Stadt", around 4 EUR). 

train schedule: www.bahn.de/en »
tram schedule: www.kvv.de »

Coming by car
take motorway A5 or A8 and leave the motorway A5 at the exit No. 47, "Ettlingen".