The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
We correlate dc maximal drain current IDSmax, pulsed output characteristics, rf small-signal and breakdown performance of normally-off InAlN/GaN HEMTs with varied gate-to-drain distance dGD. It is found that parasitic lag effects which are related to the possible surface states are not appearing at longer dGD. On the other hand compromise need to be found between the improved gate performance and...
This paper discusses 120nm AlSb/InAs HEMTs operating at ultra low drain. HEMT is fabricated with ohmic contact evaporation and Schottky T-gates realization. A deep mesa isolation is used to remove completely the buffer leading to air-bridge gate.
Metamorphic high electron mobility transistor (mHEMT) technologies with 50 and 35 nm gate length were developed for the fabrication of submillimeter-wave monolithic integrated circuits (S-MMICs) operating at 300 GHz and beyond. Heterostructures with very high electron sheet density of 6.1×1012 cm-2 and 9800 cm2/Vs electron mobility were grown on 4” GaAs substrates using a graded quaternary InAlGaAs...
The impacts of numbers of gate fingers on large signal of High Electron Mobility Transistor (HEMT) were studied in this paper. The analysis was carried out measurement using Maury Automated Tuner System (ATS) at frequency of 2.4 GHz and 5.8 GHz. The measurement results shows that the transistor that has higher number of gate fingers is less preferred for high P1dB compression and Power Added Efficiency...
The high power capabilities in combination with the low noise performance of gallium nitride (GaN) makes this technology an excellent choice for robust receivers. This paper presents the design and measured results of three different LNAs, which operate in C-, Ku-, and Ka-band. The designs are realized in 0.25 mum and 0.15 mum AlGaN/GaN microstrip technology. The measured noise figure is 1.2, 1.9...
This paper describes the design and realization of efficient GaN/AlGaN MMICs for X-band frequencies (8 - 12 GHz) in microstrip- transmission-line-technology on 3-inch s.i. SiC substrates. Four dual-stage MMICs are designed and realized based on different bandwidth requirements between 1 GHz and 3 GHz with output power levels of 15 - 20 W at X-band. After optimization of field-plate architectures and...
Conventional InAs/AlSb HEMTs suffer high gate leakage and incomplete pinch-off issues due to instable chemical property of the AlSb and GaSb materials though their excellent performance and circuit application have already been demonstrated. Based on the concerns, we proposed a two-step passivation process for minimizing the negative effect based on developed high-quality InAs/AlSb HEMT materials...
An InGaAs/InAlAs/InP HEMT has been fabricated with 0.15 mum EBL gate, double gate recess and improved Ohmic contact. While maintaining a peak transconductance (Gmp) in excess of 1000 mS/mm, an onstate burnout voltage exceeding 8 V and an operating drain voltage of 5 V have been achieved. A loadpull measurement at 40 GHz was conducted. An output power density of 471 mW/mm, a power-added efficiency...
In this paper, we present the development of an H-band (220 - 325 GHz) submillimeter-wave monolithic integrated circuit (S-MMIC) amplifier module for use in next generation active and passive high-resolution imaging systems operating around 300 GHz. Therefore, a variety of compact amplifier circuits has been realized by using an advanced 35 nm InAlAs/InGaAs based depletion-type metamorphic high electron...
A production ready pseudomorphic high electron mobility transistor (pHEMT) using i-line 0.25 mum optical gate lithography has been developed for both Ka- and Ku-band power applications. These 0.25 mum Ka- and Ku-version pHEMT devices demonstrate state-of-the-art power performance at 29 and 10 GHz, respectively. Excellent reliability has been achieved at channel temperature exceeding 275degC. Yield...
In this work, two enhancement-mode (E-mode) GaAs-based high electron mobility transistors (HEMTs), grown by molecular beam epitaxy (MBE) system, have been fabricated and investigated. We evaporated traditional platinum (Pt) and palladium (Pd) as Schottky contact metals to observe high-temperature performance. Following the 1 mum Pt/Ti/Au gate and Pd/Ti/Au gate metals deposition, the devices were thermally...
In this paper, we successfully demonstrated the D-band MMIC amplifiers based on 0.1 mum InGaAs/InAlAs/GaAs MHEMT which has two fingers of 30 mum gate width. The device exhibited a cut-off frequency (fT) of 189 GHz, and a maximum oscillation frequency (fmax) of 334 GHz. The D-band MMIC amplifier exhibited a good RF gains of 7.8 dB at a frequency of 110 GHz. Actually, the D-band MMIC amplifiers exhibited...
In this paper, the RF performance of dual material gate (DMG) AlGaN/GaN HEMT is investigated using ATLAS device simulator and presented as a high performance RF solution to microwave applications. Simulations result reveal improved RF characteristics of DMG AlGaN/GaN HEMT in comparison to Single Material Gate (SMG) AlGaN/GaN HEMT in terms of higher cut-off frequency, current gain and reduced parasitic...
In this paper a first iteration design, fabrication and test of a two-stage X-Band MMIC HPA in micro-strip AlGaN/GaN technology is reported. With 20 V drain voltage operating bias point, at 3 dB compression point, the HPA delivers a pulsed output power ranging from 21 to 28.5 W, an associated gain from 12.9 to 16.5 dB and an associated PAE from circa 30% to 40%, over the 8-10.5 GHz frequency bandwidth...
In this paper a first iteration design, fabrication and test of a two-stage X-Band MMIC HPA in micro-strip AlGaN/GaN technology is reported. With 20 V drain voltage operating bias point, at 3 dB compression point, the HPA delivers a pulsed output power ranging from 21 to 28.5 W, an associated gain from 12.9 to 16.5 dB and an associated PAE from circa 30% to 40%, over the 8-10.5 GHz frequency bandwidth...
In this paper, we present the development of advanced millimeter-wave and submillimeter-wave monolithic integrated circuits for use in active and passive high-resolution imaging systems operating beyond 200 GHz. A 210 GHz subharmonically pumped dual-gate field-effect transistor (FET) mixer has been successfully realized using our 100 nm InAlAs/InGaAs based depletion-type metamorphic high electron...
AlGaN/GaN HEMT using field plate and recessed gate for X-band application was developed on SiC substrate. Internal matching circuits were designed to achieve high gain at 8 GHz for the developed device with single chip and four chips combining, respectively. The internally matched 5.52 mm single chip AlGaN/GaN HEMT exhibited 36.5 W CW output power with a power added efficiency (PAE) of 40.1% and power...
GaN-based devices offer significant advantages for next generation military and commercial systems. Military systems benefit from high power densities of 4 to 7 W/mm depending on bias conditions along with efficiencies over 60% at frequencies through X-band, and commercial systems take advantage of excellent linearity as well. In this paper, we will review a number of commercial products that only...
W-band low-noise amplifier (LNA) has been successfully demonstrated with 50 nm metamorphic HEMT (MHEMT) technologies. 50 nm MHEMT showed a gm.max of 760 mS/mm, a fT of 216 GHz, and a fmax of 400 GHz in spite of indium content of 35 % in the channel. W-band LNA with three-stage showed the small signal gain of 9.4plusmn1.8 dB from 40 GHz to 110 GHz. These results are well suited for high frequency applications.
A metamorphic high electron mobility transistor (mHEMT) technology featuring 35 nm gate length has been developed. The optimized MBE grown layer sequence has a channel mobility and a channel electron density as high as 9800 cm2/Vs and 6.1times1012 cm-2, respectively. To enable a maximum extrinsic transconductance gm,max of 2500 mS/mm the source resistance has been reduced to 0.1 Omegamiddotmm. An...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.