Frequency multiplier measurements on heterostructure barrier varactors on a copper substrate

Influence of polarization charges in Al0.4Ga0.6N/GaN barrier varactors

“…This is still a low leakage current at bias voltages well beyond the breakdown voltages of traditional HBVs on AlGaAs/GaAs or InGaAs/InAlAs/InP material systems. 10,12 The experimentally observed breakdown voltage of about 50 V ͑for the negative bias͒ is comparable to the rough estimate of 58 V, obtained by from Ref. 18 for an abrupt p -n junction approximation.…”

“…Consequently, higher cutoff frequencies can be obtained. 12 In this letter, HBVs have been fabricated on metal-organic chemicalvapor-deposition ͑MOCVD͒-grown Al 0.4 Ga 0.6 N/GaN heterostructures and characterized. In particular, the measured capacitance-voltage curves are asymmetric and depart from the classical ones on the basis of other materials, which show a maximum at zero bias.…”

An electro-thermal HBV model

“…where a InP , T 0 and V 0 are material constants [11]. A temperature-dependent expression for the series resistance,…”

High Efficiency HBV Multipliers

“…HBV triplers (x3) have been shown to provide almost 100 mW around 100 GHz [3] and also recently a state-of-the-art efficiency of more than 21% at an output frequency of 102 GHz has been achieved [4]. At short millimetre wavelengths, corresponding to a frequency of 250 GHz, 10 mW and at least 10% efficiency have been demonstrated [5][6][7]. According to detailed analysis, there is room for a five fold improvement in terms of output power in the millimetre wavelength range [8,9].…”