Gary A. Frazier

Zero bias resonant tunnel Schottky contact diode for wide-band direct detection

A Schottky-collector resonant tunnel diode detector has been fabricated and characterized at zero bias up to 400 GHz. General device structure and fabrication are discussed, and small-signal equivalent models are presented for different diode areas. Over the measured range of 200 to 400 GHz using a monolithic antenna structure, noise equivalent power values between 3-8 pW/Hz/sup 1/2/ are achieved. The current-voltage characteristics of the diode show weak temperature dependence over a measured range of 213-323 K.

Schottky barrier contact-based RF MEMS switch

This paper presents the design, fabrication and measurement results for a novel Schottky barrier contact-based RF MEMS switch. This Schottky barrier contact allows one to operate the RF MEMS switch in a traditional capacitive mode when it is reverse biased, but can also conduct current in a forward biased state. Forward biasing the switch recombines trapped charges, thus extending the lifetime of the switch. This work intimately combines MEMS processing with solid-state electronics to produce a truly unique RF device. To the authors knowledge, nothing similar to this work has ever been reported.

50 GHz resonant tunneling diode relaxation oscillator

InAlAs/AlAs based RTDs with a peak current density over 500 kA/cm/sup 2/ have been designed and fabricated. Relaxation oscillator circuits for 20 and 50 GHz were designed using these 0.6 /spl mu/m/sup 2/ RTDs. They consist of an RTD and a 5 /spl Omega/ resistor placed in a coplanar waveguide (CPW). The measured spectrum of the 20 GHz and 50 GHz oscillators showed only odd harmonics. The measured results of the relaxation oscillators show that they have very low phase noise (low jitter), below -110 dBc/Hz at 1 MHz offset in locked-mode, and can easily be phase locked. RTD based relaxation oscillation can be readily used as clocks in high-speed signal processing applications.

Schottky Contact RF MEMS Switch Characterization

This paper presents measured results for a novel Schottky barrier contact-based RF MEMS switch, specifically S-parameter and IP2 linearity measurements. The Schottky barrier contact allows one to operate the RF MEMS switch in a traditional capacitive mode when it is reverse biased, but can also conduct current in a forward biased state to discharge trapped charges. This configuration improves reliability, but increases insertion loss. This work intimately combines MEMS processing with solid-state electronics to produce a truly unique RF device. To the authors knowledge, nothing similar to this work has ever been reported.

Schottky Barrier Contact-Based RF MEMS Switch

This paper presents the design, fabrication, and measurement results for a novel Schottky barrier contact-based radio frequency (RF) microelectromechanical systems (MEMS) switch. This Schottky barrier contact allows one not only to operate the RF MEMS switch in a traditional capacitive mode when it is reverse biased but also conduct current in a forward biased state. Forward biasing the switch recombines trapped charges, thus extending the lifetime of the switch. This paper intimately combines MEMS processing with solid-state electronics to produce a truly unique RF device.