Title :
Gate controlled 2-DEG varactor for VCO applications in microwave circuits
Author :
Anwar, Amro ; Nabet, Bahram ; Culp, James
Author_Institution :
Dept. of Electr. & Comput. Eng., Drexel Univ., Philadelphia, PA, USA
Abstract :
A novel gate-controlled Schottky diode varactor is introduced. The three terminal varactor is a modulation doped heterostructure of AlGaAs-GaAs with two Schottky contacts, similar to a metal-semiconductor-metal (MSM) diode. Schottky metal contacts are made to a two dimensional electron gas (2-DEG). The third, gate, contact is formed from highly doped n+ GaAs material to allow an open optical window that can be used for optical gating and mixing. Structure capacitance is less than 1 pF and a change of more than 30 percent from the zero bias capacitance is observed with the applied gate voltage. The interdigital structure dimensions can be scaled to cover a wide range of operation in the microwave and millimeter wave regimes
Keywords :
III-V semiconductors; Schottky diodes; aluminium compounds; gallium arsenide; microwave diodes; microwave oscillators; microwave photonics; optical control; two-dimensional electron gas; varactors; voltage-controlled oscillators; 1 pF; AlGaAs-GaAs; AlGaAs/GaAs structure; Schottky diode varactor; Schottky metal contacts; VCO applications; gate controlled 2DEG varactor; highly doped n+ GaAs material contact; interdigital structure; microwave circuits; modulation doped heterostructure; open optical window; optical gating; optical mixing; three terminal varactor; two dimensional electron gas; Capacitance; Electron optics; Epitaxial layers; Gallium arsenide; Optical materials; Optical mixing; Schottky barriers; Schottky diodes; Varactors; Voltage-controlled oscillators;
Conference_Titel :
Microwave and Optoelectronics Conference, 1999. SBMO/IEEE MTT-S, APS and LEOS - IMOC '99. International
Conference_Location :
Rio de Janeiro
Print_ISBN :
0-7803-5807-4
DOI :
10.1109/IMOC.1999.866249
