The high-performance n(+)-GaAs/p(+)-InGaP/n-GaAs high-barrier gate camel-like HFETs are successfully fabricated and demonstrated. The p(+)-InGaP layer is introduced to increase the barrier height and carrier confinement. Experimentally, good DC and AC device performances are obtained. For the studied 1 x 100 mum(2) device A (B), a gate-drain turn-on voltage of 1.6 (1.2) V, gate-drain breakdown voltage over 40 V with low leakage current of 400 (37) muA/mm, drain-source off-state breakdown voltage of 38 (39.7) V, maximum transconductance g(m,max) of 145 (147) mS/mm, unity current gain cut-off frequency f(T) of 17 (15) GHz, and maximum oscillation frequency f(max) of 33 (28) GHz are obtained, respectively, at room temperature. Moreover, the studied devices also show significantly wide and flat I-DS operation regimes of g(m), f(T) and f(max). (C) 2002 Elsevier Science Ltd. All rights reserved.