Quasi-optical HEMT and MESFET self-oscillating mixers

Planar quasi-optical receivers that compactly integrate a coupled slot antenna and a HEMT or MESFET balanced self-oscillating mixer and on the same substrate for applications in microwave and millimeter-wave receiver arrays are discussed. Both the HEMT and the MESFET circuit are designed and demonstrated at X-band. The HEMT circuit exhibits an isotropic conversion gain of 4.5 dB and a noise figure of 6.5 dB. The isotropic conversion gain of the HEMT circuit is 7.5 dB higher than the mixer diode circuit previously reported     

110-120-GHz monolithic low-noise amplifiers

The authors discuss the development of 110-120-GHz monolithic low-noise amplifiers (LNAs) using 0.1-mm pseudomorphic AlGaAs/InGaAs/GaAs low-noise HEMT technology. Two 2-stage LNAs have been designed, fabricated, and tested. The first amplifier demonstrates a gain of 12 dB at 112 to 115 GHz with a noise figure of 6.3 dB when biased for high gain, and a noise figure of 5.5 dB is achieved with an associated gain of 10 dB at 113 GHz when biased for low-noise figure. The other amplifier has a measured small-signal gain of 19.6 dB at 110 GHz with a noise figure of 3.9 dB. A noise figure of 3.4 dB with 15.6-dB associated gain was obtained at 113 GHz. The authors state that the small-signal gain and noise figure performance for the second LNA are the best results ever achieved for a two-stage HEMT amplifier at this frequency band     

Low-noise HEMT using MOCVD

Low-noise HEMT AlGaAs/GaAs heterostructure devices have been developed using metal organic chemical vapor deposition (MOCVD). The HEMT's with 0.5-µm-long and 200-µm-wide gates have shown a minimum noise figure of 0.83 dB with an associated gain of 12.5 dB at 12 GHz at room temperature. Measurements have confirmed calculations on the effect of the number of gate bonding pads On the noise figure for different gate Widths. Substantial noise figure improvement was observed Under low-temperature operation, especially compared to conventional GaAs MESFET's. A two-stage amplifier designed for DBS reception using the HEMT in the first stage has displayed a noise figure under 2.0 dB from 11.7 to 12.2 GHz.     

12GHz单片组合低噪声GaAs MESFET放大器

本文叙述了12GHz单片组合的低噪声GaAs MESFET放大器的设计和制造.每级单片放大器包含一个有源元件FET、一个隔直电容和两个射频旁路电容.在11.7～12.2GHz范围内,单级放大器增益6.0dB,噪声系数3～3.5dB,三级放大器增益16～18dB,噪声系数≤4.0dB.     

Very high gain millimeter-wave InAlAs/InGaAs/GaAs metamorphicHEMT's

We report the first demonstration of W-band metamorphic HEMTs/LNA MMICs using an AlGaAsSb lattice strain relief buffer layer on a GaAs substrate. 0.1×50 μm low-noise devices have shown typical extrinsic transconductance of 850 mS/mm with high maximum drain current of 700 mA/mm and gate-drain breakdown voltage of 4.5 V. Small-signal S-parameter measurements performed on the 0.1-μm devices exhibited an excellent f_T of 225 GHz and maximum stable gain (MSG) of 12.9 dB at 60 GHz and 10.4 dB at 110 GHz. The three-stage W-band LNA MMIC exhibits 4.2 dB noise figure with 18 dB gain at 82 GHz and 4.8 dB noise figure with 14 dB gain at 89 GHz, The gain and noise performance of the metamorphic HEMT technology is very close to that of the InP-based HEMT     

Super-low-noise performance of direct-ion-implanted 0.25-μm-gateGaAs MESFET's

The authors report on advanced ion implantation GaAs MESFET technology using a 0.25-μm `T' gate for super-low-noise microwave and millimeter-wave IC applications. The 0.25×200-μm-gate GaAs MESFETs achieved 0.56-dB noise figure with 13.1-dB associated gain at 50% I_DSS and 0.6 dB noise figure with 16.5-dB associated gain at 100% I_DSS at a measured frequency of 10 GHz. The measured noise figure is comparable to the best noise performance of AlGaAs/GaAs HEMTs and AlGaAs/InGaAs/GaAs pseudomorphic HEMTs     

Parametric analysis for a millimeter wave low noise high electron mobility transistor

This paper presents parametric analysis for low noise High Electron Mobility Transistor (HEMT) devices suitable for mm-wave radar, satellite communication, and radiometric applications. Preliminary computations reveal that pseudomorphic HEMT devices using InGaAs/GaAs heterojunction structures offer significant improvements in power added efficiency, noise figure, gain, reliability, and input power requirements compared to standard HEMT's. A Pseudomorphic HEMT device is capable of providing a room temperature noise fiqure of 3.5dB and small signal gain of 3dB at 95 GHz, approximately.     

A new low-noise FET structure

A novel monolithic FET topology has demonstrated improved minimum noise figure when compared with a conventional pi-gate FET. The structure, referred to as the spider FET, has allowed noise figures to be achieved in monolithic LNA applications that are 0.3 dB lower than in the standard 0.5-μm GaAs MESFET ion-implantation process. The improved spider FET performance is achieved by reducing the gate feed resistance and minimizing the parasitic gate-to-source capacitance in the region of the gate feed. The spider FET shows promise in 0.25-μm MESFET and HEMT (high electron mobility transistor) applications, as well as in power FET applications     

Performance of GaAs MESFET's at Low Temperatures (Short Papers)

The noise- and s-parameters of a GaAs MESFET with 1-mu m gate Iength are characterized versus temperature. At room temperature, the noise figure measured at 12 GHz is 3.5 dB. At 90 K, the noise figure decreases to 0.8 dB (T/sub e/ = 60 K). The associated gain is 8 dB. The design of a cooled amplifier for the 11.7-12.2-GHz communication band is discussed. At 60 K, the three-stage amplifier exhibits 1.6-dB noise figure (T/sub e/ = 130 K) and 31-dB gain.     

Performance of Dual-Gate GaAs MESFET's as Gain-Controlled Low-Noise Amplifiers and High-Speed Modulators

This paper describes the microwave performance of GaAs FET's with two 1-mu m Schottky-barrier gates (dual-gate MESFET). At 10 GHz the MESFET, with an inductive second-gate termination, exhibits an 18-dB gain with --26-dB reverse isolation. Variation of the second-gate potential yields a 44-dB gain-modulation range. The minimum noise figure is 4.0 dB with 12-dB associated gain at 10 GHz. Pulse modulation of an RF carrier with a 65-ps fall ad a 100-ps rise time is demonstrated. The dual-gate MESFET with high gain and low noise figure is especially suited for receiver amplifiers with automatic gain control (AGC) as an option. The MESFET is equally attractive for subnanosecond pulsed-amplitude modulation (PAM), phase-shift-keyed (PSK), and frequency-shift-keyed (FSK) carrier modulation.     

Design and performance of compact low noise GaAs MESFET amplifiers for UHF operation

The design considerations and experimental results of compact low noise GaAs MESFET Amplifiers for UHF operation are described in this paper. The miniaturized and optimized circuits are obtained by means of special matching network and CAD technique. Both a two-stage unit at 700 MHz and a three-stage unit at 1000 MHz are fabricated on a 50×60 mm² alumina substrate, and power gain of 29 dB and 30 dB, noise figure of 0.8 and 1.2 dB and bandwidth of 40 MHz (3 dB) and 100 MHz (1 dB) are obtained respectively. The satellite direct broadcasting TV receiver fabricated with a 700 MHz GaAs MESFET amplifier has clear pictures and good sound.     

Low-power W-band CPWG InAs/AlSb HEMT low-noise amplifier

We present the development of a low-power W-band low-noise amplifier (LNA) designed in a 200-nm InAs/AlSb high electron mobility transistor (HEMT) technology fabricated on a 50-/spl mu/m GaAs substrate. A single-stage coplanar waveguide with ground (CPWG) LNA is described. The LNA exhibits a noise figure of 2.5 dB and an associated gain of 5.6 dB at 90 GHz while consuming 2.0 mW of total dc power. This is, to the best of our knowledge, the lowest reported noise figure for an InAs/AlSb HEMT LNA at 90 GHz. Biased for maximum gain, the single-stage amplifier presents 6.7-dB gain and an output 1-dB gain compression point (P1dB) of -6.7dBm at 90 GHz. The amplifier provides broad-band gain, greater than 5dB over the entire W-band.     

18GHz最小噪声系数1.7dB GaAs MESFET

本文叙述了18GHz低噪声GaAs MESFET的设计和制作。讨论了影响器件性能和成品率的材料、工艺因素。在18GHz下器件的最小噪声系数为1.7dB,相关增益为7.0dB。     

10 GHz bandwidth 20 dB gain low-noise direct-coupled amplifier ICs using Au/WSiN GaAs MESFET

A low-noise direct-coupled amplifier IC with a bandwidth of 10 GHz was developed using a 0.4 mu m gate-length Au/WSiN GaAs MESFET technology. The amplifier achieved a high gain of 20 dB and a minimum noise figure of 3.2 dB with a power consumption of 365 mW.<>     

Millimeter-wave low-noise and high-power metamorphic HEMTamplifiers and devices on GaAs substrates

This paper reports on state of-the-art HEMT devices and circuit results utilizing 32% and 60% indium content InGaAs channel metamorphic technology on GaAs substrates. The 60% In metamorphic HEMT (MHEMT) has achieved an excellent 0.61-dB minimum noise figure with 11.8 dB of associated gain at 26 GHz. Using this MHEMT technology, two and three-stage Ka-band low-noise amplifiers (LNAs) have demonstrated <1.4-dB noise figure with 16 dB of gain and <1.7 with 26 dB of gain, respectively. The 32% In MHEMT device has overcome the <3.5-V drain bias limitation of other MHEMT power devices, showing a power density of 650 mW/mm at 35 GHz, with V_ds=6 V     

A 6-GHz Four-Stage GaAs MESFET Power Amplifier (Short Papers)

A 6-GHz GaAs MESFET power amplifier with 1-W output power, 26dB gain, and 8-dB noise figure is described. It is a fully integrated four-stage amplifier with an efficiency of 22 percent. The third-order intermodulation product is 31.5 dB below the carrier at an output power of 1 W.     

Direct ion-implanted 0.12 μm GaAs MESFET with ft of121 GHz and fmax of 160 GHz

An 0.12 μm gate length direct ion-implanted GaAs MESFET exhibiting excellent DC and microwave characteristics has been developed. By using a shallow implant schedule to form a highly-doped channel and an AsH₃ overpressure annealing system to optimize the shallow dopant profile, the GaAs MESFET performance was further improved. Peak transconductance of 500 mS/mm was obtained at I_ds =380 mA/mm. A noise figure of 0.9 dB with associated gain of 8.9 dB were achieved at 18 GHz. The current gain cutoff frequency f_max of 160 GHz indicates the suitability of this 0.12 μm T-gate device for millimeter-wave IC applications     

20-GHz Band Monolithic GaAs FET Low-Noise Amplifier

A 20-GHs band monolithic GaAs FET low-noise amplifier has been developed. Design and fabrication were performed by obtaining the transmission properties of the microstrip lines on a semi-insulating GaAs substrate. The developed monolithic amplifier consists of a submicron gate GaAs MESFET and the input and output distributed matching circuits on a semi-insulating GaAs substrate measuring 2.75 mm x 1.45 mm. A noise figure of 6.2dB and an associated gain of 7.5 dB were obtained at 21 GHz without any additional tuning adjustments.     

GaAs dual-gate MESFET's

Performance of GaAs dual-gate MESFET, including high-frequency noise behavior, was analyzed on the basis of Statz's model. Under the design considerations developed from the analysis, fabrication and characterization of a prototype device were carried out. The present analysis was confirmed to reproduce satisfactorily the performance observed. Minimum noise figure and associated gain observed in the device with two 1-µm gates were; 1.2 dB and 16.7 dB at 4 GHz, 2.2 dB and 16.3 dB at 8 GHz, and 3.2 dB and 12.6 dB at 12 GHz, respectively. More than 35-dB gain controllability was also obtained at 8 GHz.     

A monolithically integrated HEMT-HBT low noise high linearityvariable gain amplifier

We report on a 1-6 GHz HEMT-HBT three-stage variable gain amplifier (VGA), which is realized using selective molecular beam epitaxy (MBE). The VGA integrates an HEMT low noise amplifier with an HBT analog current-steer variable gain cell and output driver stage to achieve a combination of low noise figure, wide gain control, and high linearity. The HEMT-HBT VGA MMIC obtains a maximum gain of 21 dB with a gain control range >30 dB, a minimum noise figure of 4.3 dB, and an input IP3 (IIP3) greater than -4 dBm over 25 dB of gain central range. By integrating an HEMT instead of on HBT preamplifier stage, the VGA noise figure is improved by as much as 2 dB compared to an all-HBT single-technology design. The HEMT-HBT MMIC demonstrates the functional utility and RF performance advantage of monolithically integrating both HEMT and HBT devices on a single substrate