Active two-terminal devices as local oscillators for low-noise receiver systems at submillimeter wave frequencies

Abstract

The power capabilities of three different two-terminal devices, GaAs IMPATT diodes, inP Gunn devices and GaAs TUNNETT diodes are evaluated. Two different selective etching technologies have been employed to fabricate devices on either a diamond heat sink or an integral heat sink. The reported RF power levels in fundamental mode are 20 mW at 120 GHz and 15 mW at 135 GHz for D-band GaAs IMPATT diodes, 21 mW at 120 GHz, 17 mW at 133 GHz and 8 mW at 155 GHz for D-band InP Gunn devices and up to 35 mW around 103 GHz for W-band GaAs TUNNETT diodes. Typical dc to RF conversion efficiencies range from 0.9% up to over 4.0%, In second harmonic mode power levels of 0.25 mW at 223 GHz were measured from TUNNETT diodes and 0.4 mW at 220 GHz from a Gunn device. Aktive Zweipol-Bauelemente als Lokaloszillatoren fiir rauscharme Empfiingersysteme im Frequenzgebiet der Submillimeterwellen Ubersicht: Die Leistungsf/ihigkeit dreier verschiedener Zweipolbauelemente, GaAs-IMPATT-Dioden, InP-Gunn-Bauelemente und GaAs-TUNNETT-Dioden, wird untersucht. Zwei unterschiedliche Herstellungsverfahren mit selektivem ~tzen wurden eingesetzt, um Bauelemente auf einer Diamant-bzw. integrierten Wfirmesenke herzustellen. Hochfrequenzausgangsleistungen yon 20roW bei 120 GHz und 15 mW bei 135 GHz wurden mit GaAs-IMPATT-Dioden ffir das D-Band erzielt, 21 mW bei 120 GHz, 17 mW bei 133 GHz und 8 mW bei 155 GHz mit InP-Gunn-Bauelementen fiir das D-Band und bis zu 35 mW um 103 GHz mit GaAs-TUN-NETT-Dioden ffir das W-Band. Typische Hochfrequenzwirkungsgrade lagen zwischen 0,9% und fiber 4%. Bei der ersten Oberwelle wurden mit TUNNETT-Dioden HF-Leistungen von 0,25 mW bei 223 GHz gemessen und 0,4 mW bei 220 GHz mit einem Gunn-Bauelement. gies. The experimental results on D-band InP Gunn devices agree well with simulations [3] and indicate that fundamental mode operation can be extended to the upper D-band. Since IMPATT diodes, TUNNETT diodes and Gunn devices are nonlinear devices, this paper also focuses on harmonic power extraction.

Development of GaAs Gunn Diodes and Their Applications to Frequency Modulated Continuous Wave Radar

“…Figure 2 shows a scanning electron microscope (SEM) photograph of the fabricated GaAs Gunn diodes. 7,8)…”

Improvement of Fabrication Technology for InP Gunn Devices Using Trench Method

“…The layers were, in order of growth, a 1.5 pim-thick n+ InP buffer layer doped at 1 x 1018 cm-3, the active layer of 1.8 pim of InP doped at 1.1 x 1016 cm-3. The diodes with nn+ structure exhibit much lower current density, higher output power, and superior frequency stability with temperature variation than the conventional n+nn+ structure [10]. The common fabrication procedure of the InP Gunn diode was shown in Fig.…”

“…Though this method facilitates handling of the thinned epi-wafer there are some problems such as formation of cracks in epi-layer during anode ohmic alloy process. To avoid the formation of cracks which are caused by the difference in the thermal expansion coefficients between the InP epi-layer and the Au-plated integral heat sink [10][11] the diamond heat sink can be used [12]. In thinning the wafer first, it is thinned prior to the front-side process.…”