Broadband Zero-Bias RF Field-Effect Rectifiers Based on AlGaN/GaN Nanowires

Abstract

Microwave zero-bias rectifiers are fast devices capable of rectifying RF signals without applied bias, which have applications ranging from RF power detection to THz imaging systems. Here we present gated nanowire field-effect rectifiers (NW-FERs) fabricated with a process compatible with other RF devices on a standard AlGaN-GaN High Electron Mobility Transistor (HEMT) platform as a new potential RF zero-bias diode. Signal rectification relies on the electrostatic modulation of the gated-NW carrier concentration, which is optimized by a judicious NW width design. NW-FERs presented a large curvature (30.1 V −1), close to the theoretical limit (38.7 V −1) for ideal Schottky diodes, and an excellent trade-off between a flat frequency response, up to a few tens of GHz, and a large responsivity (3000 V/W). The compatible fabrication process and the very good results provide a promising high-performance zerobias diode architecture that could be integrated on AlGaN/GaN microwave monolithic integrated circuits (MMICs).

Trap-related frequency dispersion of zero-bias microwave responsivity at low temperature in GaN-based self-switching diodes

“…Concerning GaN-based SSDs, even if not showing an evident rectifying behaviour as showed by narrow InGaAs or GaAs SSDs [18,21,22], they have demonstrated their validity as RF detectors, exhibiting a responsivity up to 100 V W −1 at 0.30 THz [24] and 2 V W −1 (in free-space) at 0.69 THz [25]. Indeed, recently, more complex structures have been studied, such as Gated-SSDs (GSSDs), which are SSDs with a Schottky gate [26], or gated nanowire field-effect rectifiers (NW-FERs) [27], with responsivities of 600 V W −1 and 3000 V W −1 , respectively.…”

Extremely high frequency Schottky diodes based on single GaN nanowires

“…According to equation (2) we defined the cutoff frequencies that were found to be in the EHF band. The best result was 165.8 GHz, which is higher than corresponding value for planar GaN based structures [17]. Further increase of the working frequency can be achieved by improvements of the inhomogeneously doped NWs, allowing reduce of R s and C j values.…”

“…In turn, Schottky-contacted NWs are in the focus of intensive research aimed at developing high sensitive and fast responsible bio/gas/chemical/photo/strain sensors for Internet-of-Things [16]. There is a row of investigations dedicated to Schottky barrier diodes based on GaN NWs [17][18][19][20][21][22], but despite the significant potential of GaN NWs from both material and device properties perspectives, frequency possibilities of NW-based Schottky diodes are still requiring more study.…”

High Sensitivity Envelope Detector Assisted by Microwave Photonics

“…A Highperformance HEMT-based ED can achieve a sensitivity of around 12,000 V/W for the microwave W band (Changfei et al, 2015). Low barrier Schottky diode can be found at 3,000 V/W for few tens of GHz (Santoruvo et al, 2020).…”