A high maximum frequency of oscillation (f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> ) 910 GHz was achieved at InAlAs/InGaAs highelectron mobility transistors (HEMTs) with a relatively long gate length (L xmlns:xlink="http://www.w3.org/1999/xlink">G</sub> 75 nm by adopting an asymmetric recess and double-side-doped structure. The f improved significantly extending the drain-side xmlns:xlink="http://www.w3.org/1999/xlink">RD</sub>...

This letter reports on an InAlGaN/GaN high-electron-mobility transistor (HEMT) employing a SiC/diamond-bonded heat spreader with record high output power density of 22.3 W/mm. A quaternary In-added InAlGaN barrier enabled both the large current over 1 A/mm and breakdown voltage 257 V. The drain bias was increased as 100 V for S-band load-pull measurement, leading to operation. Furthermore, thermal resistance reduced by 60%, from 18.8 7.2°C/W, SiC/diamond spreader. dissipation effect clearly...

This paper describes the implementation of 60 and 77GHz PAs in standard 90nm CMOS technology. An accurate transistor model is developed that enables designing circuits operating at frequencies up to 80GHz. The are designed with a unique matching topology for reducing RF signal loss networks.

We demonstrated a W-band high-power-density MMIC power amplifier with 80 nm InAlGaN/GaN HEMTs. The consists of two-stage cascade units, each which has two transistors the same gate periphery for high gain and low-loss matching circuit. achieved maximum output 1.15 W PAE 12.3 % at 86 GHz under CW operation. Its density reached 3.6 W/mm, representing highest performance GaN HEMT amplifier.

The study reports the findings on a quaternary InAlGaN/GaN high electron mobility transistor (HEMT) employing thermal chemical vapor deposition (TCVD) silicon nitride (SiN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> ) passivation with record output power density of 31.0 W/mm in X-band. We compared two different SiN methods, namely, TCVD deposition, and plasma-enhanced CVD (PECVD) for HEMTs investigated effects device performance....

Abstract An AlGaN/GaN high-electron-mobility transistor (HEMT) on a free-standing GaN substrate achieved impressive power-added and drain efficiencies of 85.2% 89.0%, respectively, at 2.45 GHz. We improved the channel quality by reducing C concentration eliminated buffer leakage path removing residual Si substrate-epitaxial layer interface. These improvements, combined with reduction in dislocation density elimination nucleation using substrate, contributed to enhanced efficiency. To best...

GaN-based high-electron-mobility transistors (HEMTs) fabricated on SiC substrates were successfully bonded to single-crystal diamond heat spreader by a surface activated bonding method with thin titanium (Ti) cover layer. A Ti layer the improved strength of SiC/diamond interface since formation an amorphous was suppressed. This process applied high-output power InAlGaN/GaN HEMTs spreaders. The structure reduced thermal resistance devices and enabled their high-power operation.

Abstract This paper demonstrates highly efficient GaN high-electron-mobility transistors (HEMTs) on substrates with reduced interface contamination. By applying a hydrofluoric acid-based pre-growth treatment to substrate, the Si impurity concentration at between substrate and epitaxial layer can successfully be reduced. RF performance was enhanced by owing suppression of Si-induced parasitic loss. As result, HEMTs exhibited an excellent power-added efficiency 82.8% 2.45 GHz. To best our...

This paper reports on an AlGaN/GaN high-electron-mobility transistor (HEMT) free-standing AlN substrates with a record-high output power density of 24.4 W/mm at the X-band. A high-drain current operation 1.4 A/mm was realized by employing high-density 2-dimensional electron gas channel and regrown Ohmic contacts. Furthermore, high-voltage 110 V achieved owing to high-breakdown SiNx layer grown low-pressure/high-temperature chemical vapor deposition. Three-stage AlGaN buffer layers improved...

This paper proposes a new topology for broadband low-noise-amplifier (LNA). A common-gate (CG) amplifier with matching inductor composes unit cell, and the cells are cascaded to increase gain. As both input output impedances of cell matched 50 Ω wide frequency range, it is possible gain while maintaining bandwidth. Thus, high-gain performance can be obtained using this topology. The other features its small size, low power consumption, current reuse presents design methodology multistage CG...

This paper describes a 0.18 /spl mu/m CMOS distributed amplifier with optimized source degeneration which achieves 4 dB gain and 39 GHz bandwidth within 1 variation.

A <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">W</i> -band millimeter-wave transmitter and receiver that are based on impulse radio (IR) architecture were developed. The IR-based apparatuses have an optical-fiber input/output interface board supports multi protocol signals (OC-192 10 GbE) implements a forward error correction (FEC), enabling 10-Gb/s data transmission both in space fiber seamlessly. Analyzing model with simple on/off...

A maximum frequency of oscillation (fmax) 1.3 THz was achieved using an extended drain-side recess structure InAlAs/InGaAs high-electron-mobility transistors (HEMTs), although the gate length relatively long at 75 nm. The high fmax improved by reducing drain output conductance (gd). use asymmetric and double-side doping above below a channel region were effective in gd. Further improvements transconductance (gm) gd distance between source electrodes.

We have developed a distributed amplifier for LiNbO/sub 3/ modulator driver using double-doped AlGaAs-InGaAs-AlGaAs pseudomorphic high electron mobility transistors (p-HEMTs). By stabilization and negative resistance control technique with source inductance grounded coplanar waveguided lines, we obtained gain of 15 dB, bandwidth 54 GHz, 6-V/sub PP/ output. These results indicate that our circuit is leading candidate use as in 40-Gb/s fiber-optic communication systems.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFormation of Soluble Polyethylene by Hydrogenation Alkali-Metal-Doped PolyacetyleneHideki Shirakawa, Masaru Sato, Akito Hamano, So-ichiro Kawakami, Kazuo Soga, and Sakuji IkedaCite this: Macromolecules 1980, 13, 2, 457–459Publication Date (Print):March 1, 1980Publication History Published online1 May 2002Published inissue 1 March 1980https://pubs.acs.org/doi/10.1021/ma60074a052https://doi.org/10.1021/ma60074a052research-articleACS...

At mm-wave frequency, the layout of CMOS transistors has a larger effect on device performance than ever before in low frequency. In this work, distance between gate and drain contact (D <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">gd</sub> ) been enlarged to obtain better maximum available gain (MAG). A 0.6 dB MAG improvement is realized when D changes from 60 nm 200 nm. By using asymmetric-layout transistor, four-stage common-source noise...

The minimum noise figure (NF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">min</sub> ) at 94 GHz was improved effectively by employing a cavity structure in the interconnection process, even though wide gate head used InP-based high-electron-mobility transistors (HEMTs). is effective improving NF since resistance reduced, while increased parasitic capacitance passivated affects figure. Then, eliminated successfully around region. We measured...

Low-temperature deposition has been required for preparing SiNx films of high density, refractive index, and low hydrogen content various applications. We examine the characteristics deposited at temperature by reactive sputtering plasma-enhanced CVD under different conditions. The results reveal that we can give an outline preparation conditions provide properties pretreatment Si target improves sputter-deposited reducing amount oxygen incorporation.

This paper describes a new preamplifier IC with 0,15-/spl mu/m gate InP-based high electron mobility transistors (HEMTs) for high-speed fiber optic communication system. The consists of lumped-element transimpedance amplifier (TIA) the input stage and highly stabilized distributed cascode-configured unit cells gain stage. A gain-peaking technique was employed to enhance bandwidth flatness preamplifier. peaking profile compensates lack TIA. As result, we achieved flat 52 dB/spl Omega/ 49 GHz.

A fully-integrated K-band differential power amplifier was designed in 65 nm CMOS. The comprised of the 2-stage cascode configuration has matching networks based on transformer. To match impedances, turn ratios each transformer were to be 1:1 for input stage, 2:1 inter and 1:1.5 output respectively. saturation more than 20 dBm obtained band between 16 GHz 25 GHz. peak value 23.8 dBm, added efficiency (PAE) 25.1 % at 19 chip occupied area including DC RF pads is 1.2 × 0.8 mm.

Gallium nitride high electron mobility transistors (GaN HEMTs) were developed for millimeter-wave power amplifier applications. The device with a gate length of 80 nm and an InAlN barrier layer exhibited drain current more than 1.2 A/mm breakdown voltage 73 V. A cut-off frequency fT 113 GHz maximum oscillation fmax 230 achieved. output density reached 1 W/mm linear gain 6.4 dB at load-pull measurements 90 GHz. And we extracted equivalent circuit model parameters the InAlN/GaN HEMT showed...

The authors present a 3-V dual-modulus (/64/65, /128/129) prescaler that operates up to 1.0 GHz with 3-mW (V/sub CC/ at 2.58 V) power consumption. Under the normal supply voltage of 3 V, maximum operating frequency and dissipation are 1.18 5 mW, respectively. This has been achieved by accurate circuit simulation use 0.2- mu m bipolar technology.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Abstract Summary: Alternating copolymers between substituted 1,3,5‐triazine (substituent = alkyl or amine) and thiophene bithiophene are synthesized. The copolymer of amino‐1,3,5‐triazine with is soluble in organic solvents, transparent most parts the visible region, photoluminescent. receives electrochemical n ‐doping an E pc −2.08 V vs Ag + /Ag shows a time‐of‐flight electron drift mobility 2.0 × 10 −4 cm 2 · −1 s , which larger than that widely used Al(8‐quinolinolato) 3 . Structure...

This paper describes 94-GHz band low-noise and high-gain amplifier MMICs using InP HEMTs, which have been developed for passive millimeter-wave (PMMW) imaging. To achieve a high gain with low noise performance, we propose new stabilizing technique the amplifier. The measured figure was 3.2 dB 33 dB. In addition, PMMW imager this We also demonstrated an example of image acquired by imager.