TriQuint Semiconductor

About: TriQuint Semiconductor is a based out in . It is known for research contribution in the topics: Amplifier & Monolithic microwave integrated circuit. The organization has 637 authors who have published 673 publications receiving 10318 citations.

HF, VHF, and UHF systems and technology

Abstract: A wide variety of unique systems and components inhabits the HF, VHF, and UHF bands. Many communication systems (ionospheric, meteor-burst, and troposcatter) provide beyond-line-of-sight coverage and operate independently of external infrastructure. Broadcasting and over-the-horizon radar also operate in these bands. Magnetic-resonance imaging uses HF/VHF signals to see the interior of a human body, and RF heating is used in a variety of medical and industrial applications. Receivers typically employ a mix of analog and digital-signal-processing techniques. Systems for these frequencies make use of RF-power MOSFETs, p-i-n diodes, and ferrite-loaded transmission-line transformers.

High-Efficiency Harmonically Terminated Diode and Transistor Rectifiers

Abstract: This paper presents a theoretical analysis of harmonically terminated high-efficiency power rectifiers and experimental validation on a class-C single Schottky-diode rectifier and a class- F-1 GaN transistor rectifier. The theory is based on a Fourier analysis of current and voltage waveforms, which arise across the rectifying element when different harmonic terminations are presented at its terminals. An analogy to harmonically terminated power amplifier (PA) theory is discussed. From the analysis, one can obtain an optimal value for the dc load given the RF circuit design. An upper limit on rectifier efficiency is derived for each case as a function of the device on-resistance. Measured results from fundamental frequency source-pull measurement of a Schottky diode rectifier with short-circuit terminations at the second and third harmonics are presented. A maximal device rectification efficiency of 72.8% at 2.45 GHz matches the theoretical prediction. A 2.14-GHz GaN HEMT rectifier is designed based on a class-F-1 PA. The gate of the transistor is terminated in an optimal impedance for self-synchronous rectification. Measurements of conversion efficiency and output dc voltage for varying gate RF impedance, dc load, and gate bias are shown with varying input RF power at the drain. The rectifier demonstrates an efficiency of 85% for a 10-W input RF power at the transistor drain with a dc voltage of 30 V across a 98-Ω resistor.

Power combiner using tri-plane antennas

Abstract: A power combining apparatus includes a waveguide structure and a plurality of antenna elements arranged in the waveguide structure, wherein each of the antenna elements comprises a center planar antenna layer, two outer planar antenna layers arranged on opposite sides of the center planar antenna layer, a non-conductive layer between the center planar antenna layer and one of the outer planar antenna layers, and another non-conductive layer between the center planar antenna and the other one of the outer planar antenna layers. The power combining apparatus includes a waveguide structure having an input, an output, and a plurality of antenna elements arranged in the waveguide structure, wherein each antenna element is configured to transform an electric field direction of an electromagnetic field by substantially 90 degrees rotation about a longitudinal axis of the waveguide structure, wherein a bandwidth of the antenna is less than, equal to, or greater than a decade of frequency range.

An improved GaAs MESFET model for SPICE

Abstract: A SPICE model for modeling GaAs MESFET devices more accurately is discussed. In particular, small-signal parameters are accurately modeled over a wide range of bias conditions. These results were achieved by modifying the model equations of H. Statz et al. (see IEEE Trans. Electron. Devices, vol.3, no.2, p.160-9, 1987) to better represent the variation of I/sub ds/ as a function of the applied voltage. The model applies over a large range of pinch-off voltages, allows size scaling of devices, and is suited for modeling R/sub ds/ changes with frequency. The Statz equations are used to represent diode characteristics and capacitive components of the model. >

TEM Observation of Crack- and Pit-Shaped Defects in Electrically Degraded GaN HEMTs

Abstract: AlGaN/GaN high-electron mobility transistors stressed under dc bias at various channel temperatures were studied using transmission electron microscopy for evidence of physical damage. Stressed devices consistently developed crack- and pit-shaped defects in the AlGaN/GaN crystal material under the drain-side edge of the gate, whereas side-by-side as-processed unstressed devices did not show these features. Furthermore, the amount of physical damage was found to correlate to the amount of electrical degradation as measured by the change in IDmax from before and after stress. The formation of these defects is consistent with the theory of damage from the inverse piezoelectric effect.