In this letter, we report on the radio frequency (RF) characterization up to 110 GHz of probeable high-performance heterostructure barrier varactors fabricated from InP-based strained epilayers, By making use of a dual step-like barrier scheme, the voltage handling is as high as 12 V whereas the capacitance ratio at 85 GHz achieves 5:1 for a zero-bias capacitance of 1 fF/mu m(2) without deviation in the frequency band investigated. Good agreement between calculated and measured scattering parameters is found on the basis of electromagnetic simulation of diode embedding.