Tunnel injection transit-time diodes (TUNNETT) were fabricated with molecular layer epitaxy (MLE) and a 390 x 440 mu m patch antenna was coupled with the GaAs TUNNETT diode for cavity less sub-terahertz (THz) oscillators The obtained sub terahertz continuous wave (CW) was 177-197 GHz with a detected power of -35 3 dBm at 197 GHz under a bias current of 550 mA (C) 2010 Elsevier Ltd All rights reserved