Characterisation and analytical modelling of GaN HEMT-based varactor diodes

• Published in: Electronics letters Vol. 51; no. 23; pp. 1930 - 1932
• Main Authors: Hamdoun, A, Roy, L, Himdi, M, Lafond, O
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 05.11.2015; IET
• Subjects: Capacitance; Computer Science; Devices; Electronics; Engineering Sciences; equivalent circuits; Exact solutions; gallium compounds; Gallium nitrides; GaN; HEMT based varactor diodes; high electron mobility transistors; III‐V semiconductors; Mathematical analysis; Mathematical models; microwave diodes; microwave field effect transistors; Networking and Internet Architecture; physical equivalent circuit; Semiconductor devices; Semiconductor technology; size 0.15 mum; size 0.5 mum; small signal measurements; Varactor diodes; varactors; wide band gap semiconductors; microwave diodes; gallium compounds; small signal measurements; high electron mobility transistors; physical equivalent circuit; microwave field effect transistors; size 0.15 mum; equivalent circuits; GaN; varactors; size 0.5 mum; wide band gap semiconductors; HEMT based varactor diodes; III-V semiconductors
• ISSN: 0013-5194; 1350-911X; 1350-911X
• DOI: 10.1049/el.2015.2362

Varactor diodes fabricated in 0.5 and 0.15 µm GaN HEMT (high-electron-mobility transistor) processes are modelled. The devices were characterised via DC and RF small-signal measurements up to 20 GHz, and fitted to a simple physical equivalent circuit. Approximate analytical expressions containing empirical coefficients are introduced for the voltage dependency of capacitance and series resistance. The analytical solutions agree remarkably well with the experimentally extracted C–V curves and can be used as a general model to represent the nonlinear behaviour of GaN-based varactors devices.