A 218‐GHz second‐harmonic multiquantum well GaAs‐based planar Gunn diodes

Abstract

We present a multiquantum‐well channel GaAs‐based planar Gunn diode. By introducing extra channels, the output RF power has been significantly improved compared to single‐channel GaAs‐based planar Gunn diodes. For a 1.14 μm length and 60 μm wide device, the highest power achieved was approximately −4 dBm operating in fundamental mode at 109 GHz, and −26.6 dBm at its second harmonic at 218 GHz. The DC‐to‐RF conversion efficiency was ∼0.3% for the fundamental mode of oscillation. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:686–688, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27393

Planar gunn diode characterisation and resonator elements to realise oscillator circuits

“…The planar construction of the Gunn diode is shown as a schematic in Figure-1 and was developed by the Universities of Glasgow and Aberdeen [1][2][3][4], The device material layers were grown by mo lecular beam epitaxy (M BE) and fro m top to bottom in Figure 1 consist of a highly doped GaAs layer (15n m), the active channel region consisting of 50n m of un-doped GaAs between 20n m layers of double δ-doped Al 0.23 Ga 0.77 As, 50n m GaAs buffer layer g rown directly to a 620 µm thick semi-insulating GaAs substrate. The metal anode and cathode ohmic contact regions were defined by electron beam lithography using polymethylmethacrylate (PMMA) resist and formed using Pd/ Ge/Au/Pt/Au deposited by e-beam evaporation and annealed at 400ºC.…”

“…The device structure was compatible with waveguide or coaxial circuits but difficult to integrate into a p lanar circuit technology, for example microstrip and coplanar waveguide (CPW). In recent years a planar diode has been developed [1][2][3][4][5], in which the anode and cathode contacts are on the top surface of the semiconductor making it d irectly co mpatible with coplanar waveguide technology. This has enabled for the first time Gunn diode technology to be explored in p lanar form, for examp le Monolithic Microwave Integrated Circuits (MMICs).…”

An AlGaAs/GaAs‐based planar Gunn diode oscillator with a fundamental frequency operation of 120 GHz

“…The construction of the planar Gunn diode is shown as a schematic in Figure and was developed by the Universities of Glasgow and Aberdeen . The device material layers were grown by molecular beam epitaxy and from top to bottom in Figure consists of a highly doped (≥3.5 × 10 18 cm −3 ) GaAs layer (15 nm); the active channel region consisting of 50 nm of undoped GaAs between 20 nm layers of double δ‐doped Al 0.23 Ga 0.77 As and 500 nm GaAs buffer layer grown directly to a 620‐μm‐thick semi‐insulating GaAs substrate.…”

Cofabrication of Planar Gunn Diode and HEMT on InP Substrate

“…The addition of extra doping layers [8] and the introduction of strained In 0.23 Ga 0.77 As for the formation of the channel layer [9] led to the significant improvement of the power characteristics. The maximum generated power was boosted to −4 dBm in an alternating In 0.23 Ga 0.77 As/GaAs layer structure with seven channel layers [10]. However, the current density of the multichannel devices was increased by approximately five times in comparison with the singlechannel devices, indicating that not all the channels contribute to the oscillation.…”