Heterostructure Barrier Varactors for High Efficiency Frequency Multipliers
Doktorsavhandling, 2000

This thesis describes the Heterostructure Barrier Varactor (HBV) and its application in frequency multipliers. Different HBV materials, fabrication processes, and device models are presented. The aim of this work is to improve the efficiency of HBV frequency multipliers. Efficiency limitations of symmetric varactor frequency multipliers are investigated. Simple varactor models with capacitance-voltage characteristics of varying shapes have been analyzed. Calculations show that the conversion efficiency is improved for a C(V)-shape with large non-linearity at zero-volt bias. For quintuplers, the optimal embedding impedance at the third harmonic is an inductance in reso-nance with the varactor capacitance. Results are presented from frequency tripler measurements with planar GaAs/AlGaAs HBVs. Simulations and cooled measurements show that self-heating yields excessive conduction current that decreases the efficiency. A new design of planar HBVs has been tested with improved thermal conductance and reduced series resistance. A maximum output power of 4 mW was generated at 246 GHz with an efficiency of 4.8%. A new fabrication process is presented in which HBVs are fabricated on a copper substrate. This process offers reduced parasitic losses and improved thermal conductivity and is carried out without degrading the electrical characteristics. In a frequency tripler experiment, a maximum output power of 7.1 mW was generated at 221 GHz with a flange-to-flange efficiency of 7.9%. A quasi-optical HBV tripler is presented. 11.5 mW was generated at 141 GHz with a maximum efficiency of 8%. A non-linear transmission line frequency tripler, consisting of a finline loaded with 15 HBVs, is presented. A maximum output power of 10 mW was generated at 130.5 GHz with an efficiency of 7%, and the 3 dB bandwidth was measured to 10%. A simple design method for the calculation of optimum embedding impedances, maximum efficiency, and pump power for HBV triplers is presented.

frequency multiplier

Heterostructure Barrier Varactor (HBV)

millimeter wave

submillimeter wave

power source

HC 1, Hörsalsvägen 14
Opponent: Dr. Robert M. Weikle II, University of Virginia, Charlottesville, USA

Författare

Lars Dillner

Institutionen för mikroelektronik

Frequency Multiplier Measurements on Heterostructure Barrier Varactors on a Copper Substrate

IEEE Electron Device Letters,; Vol. 21(2000)p. 206-208

Artikel i vetenskaplig tidskrift

Improved Diode Geometry for Planar Heterostructure Barrier Varactors

Tenth International Symposium on Space Terahertz Technology,; (1999)p. 485-491

Paper i proceeding

Heterostructure-Barrier-Varactor Design

IEEE Transactions on Microwave Theory and Techniques,; Vol. 48(2000)p. 677-682

Artikel i vetenskaplig tidskrift

Analysis of Symmetric Varactor Frequency Multipliers

Microwave and Optical Technology Letters,; Vol. 15(1997)p. 26-29

Artikel i vetenskaplig tidskrift

Effects of Self-Heating on Planar Heterostructure Barrier Varactor Diodes

IEEE Transactions on Electron Devices,; Vol. 45(1998)p. 2298-2303

Artikel i vetenskaplig tidskrift

A 141-GHz Quasi-Optical HBV Diode Frequency Tripler

Tenth International Symposium on Space Terahertz Technology,; (1999)p. 492-500

Paper i proceeding

A Distributed Heterostructure Barrier Varactor Frequency Tripler

IEEE Microwave and Guided Wave Letters,; Vol. 10(2000)p. 24-26

Artikel i vetenskaplig tidskrift

Heterostructure Barrier Varactors on Copper Substrate

Electronics Letters,; Vol. 35(1999)p. 339-341

Artikel i vetenskaplig tidskrift

Ämneskategorier

Elektroteknik och elektronik

ISBN

91-7197-902-6

Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 1589

Technical report - School of Electrical and Computer Engineering, Chalmers University of Technology, Göteborg, Sweden: 387

HC 1, Hörsalsvägen 14

Opponent: Dr. Robert M. Weikle II, University of Virginia, Charlottesville, USA