Frequency multiplier measurements on heterostructure barrier varactors on a copper substrate

We hare fabricated heterostructure barrier varactors (HBV) on a copper subs trate, which offers reduced spreading resistance, and improved thermal cond uctivity compared to an LnP substrate. The devices are fabricated without d egrading the electrical characteristics. The three-barrier HBV material gro wn by MOVPE has a leakage current of only 0.1 mu A/mu m(2) at 19 (V) under bar, The maximum capacitance is 0.54 fF/mu m(2). In It frequency tripler ex periment a maximum output power of 7.1 mW was generated at 221 GHz with a f lange-to-flange efficiency of 7.9%.