The HBT technology is now mature and offers a great variety of RF products for telecom applications, specially power amplifiers for which a high level of linearity is requested. The reliability has been the limiting factor in the supplying of high power amplifiers and nowadays only medium HPA are available in catalogue. Also, regarding the huge quantities of papers published in the mid 90s relating the interest of this technology for high PAE / Power, very few of the competitors have been successful. In Europe, open foundry services are available through UMS for high power applications ranging up to Ku band. New advances in term of thermal management / electrical behaviour and topology have been pushed ahead tending towards the limit of high power density. An improved version is underway to set up a doubling of the output power by cell (2.5W in X- Band). To address the market of the base stations, very high power transistors have been designed. Also, the Collector-Up DHBT offer potential improvement in term o high power at high frequency (1W at 40 GHz).