High performance ion-implanted low noise GaAs MESFET's

Low noise GaAs MESFET's fabricated by ion-implanting into AsCl3VPE buffer layers have demonstrated not only excellent dc and RF performance, but also a highly reproducible process. The average noise figure and associated gain of four device lots at 12 GHz are 1.6 dB and 10.0 dB, respectively. The standard deviation of noise figure and associated gain from device lot to lot are 0.03 dB and 0.19 dB, respectively. And the standard deviation of noise figure and associated gain from device to device for 35 devices over four lots are 0.13 dB and 0.47dB, respectively. The best device performance includes a 1.25 dB noise figure with 10.46 dB associated gain at 12 GHz for a 0.5 µm × 300 µm FET structure. These results demonstrate the excellent performance and process consistency of ion implanted MESFET's.     

Submicron Single-Gate and Dual-Gate GaAs MESFET's with Improved Low Noise and High Gain Performance

Microwave performance of single-gate and dual-gate GaAs MESFET's with submicron gate structure is described. Design consideration and device technologies are also discussed. The performance of these GaAs MESFET's exceeds previous performance with regard to lower noise and higher gain up to X band: 2.9-dB noise figure (NF) and 10.0-dB associated gain at 12 GHz for a 0.5-mu m single-gate MESFET, and 3.9-dB NF and 13.2-dB associated gain at the same frequency for a dual-gate MESFET with two 1-mu m gates.     

Improved noise performance of GaAs MESFET's with selectively ion-implanted n+source regions

Superior microwave performance of 0.5-µm-gate GaAs MESFET's has been attained by a structure with selectively ion-implanted n⁺source regions. The source series resistance is reduced and the noise figure of 2.1 dB is observed at 12 GHz.     

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     

Improved short-channel GaAs MESFET's by use of higher doping concentration

GaAs MESFET's with highly doped channels up to5 times 10^{18}cm^-3and with both micrometer and submicrometer gates were fabricated and evaluated. FET's with 1.2-µm gates show an extrinsic transconductance of more than 250 mS/mm, cutoff frequencies around 20 GHz, and a noise figure of 2 dB at 8 GHz with 9-dB associated gain. Breakdown voltage is higher than 6 V. FET's with 1.2- and 0.4-µm gates were simultaneously fabricated on the same wafer to investigate short-channel effects. The short-channel devices show a good saturation behavior and no shift in the threshold voltage compared to the long-channel devices thus demonstrating a pronounced alleviation of short-channel effects as experienced for1 times 10^{17}cm^-3doping levels. The influence of doping concentration on the performance of devices with micrometer and submicrometer gates upon doping concentration is investigated by detailed computer simulations. Good agreement between theoretical and experimental results is obtained. From these results improved technological approaches are pointed out.     

Ultra-low-noise indium-phosphide MMIC amplifiers for 85-115 GHz

This paper describes a high-performance indium-phosphide monolithic microwave integrated circuit (MMIC) amplifier, which has been developed for cooled application in ultra-low-noise imaging-array receivers. At 300 K, the four-stage amplifier exhibits more than 15-dB gain and better than 10-dB input and output return loss from 80 to 110 GHz. The room-temperature noise figure is typically 3.2 dB, measured between 90-98 GHz. When cooled to 15 K, the gain increases to more than 18 dB and the noise figure decreases to 0.5 dB. Only one design pass was required to obtain very good agreement between the predicted and measured characteristics of the circuit. The overall amplifier performance is comparable to the best ever reported for MMIC amplifiers in this frequency band     

60-GHz noise performance of ion-implanted InxGa1-xAs MESFET's

The authors report the 60-GHz noise performance of low-noise ion-implanted In_xGa_1-xAs MESFETs with 0.25 μm T-shaped gates and amplifiers using these devices. The device noise figure was 2.8 dB with an associated gain of 5.6 dB at 60 GHz. A hybrid two-state amplifier using these ion-implanted In_xGa_1-x As MESFETs achieved a noise figure of 4.6 dB with an associated gain of 10.1 dB at 60 GHz. When this amplifier was biased at 100% I _dss, it achieved 11.5-dB gain at 60 GHz. These results, achieved using low-cost ion-implantation techniques, are the best reported noise figures for ion-implanted MESFETs     

GaAs Monolithic MIC's for Direct Broadcast Satellite Receivers

A 12-GHz low-noise amplifier (LNA), a 1-GHz IF amplifier (IFA), and an 11-GHz dielectric resonator oscillator (DRO) have been developed for DBS home receiver applications by using GaAs monolithic microwave integrated circuit (MMIC) technology. Each MMIC chip contains FET's as active elements and self-biasing source resistors and bypass capacitors for a single power supply operation. It also contairns dc-block and RF-bypass capacitors. The three-stage LNA exhibits a 3.4-dB noise figure and a 19.5-dB gain over 11.7-12.2 GHz. The negative-feedback-type three-stage IFA shows a 3.9-dB noise figure and a 23-dB gain over 0.5-1.5 GHz. The DRO gives 10.mW output power at 10.67 GHz, with a frequency stability of 1.5 MHz over a temperature range from -40-80°C. A direct broadcast satellite (DBS) receiver incorporating these MMIC's exhibits an overafl noise figure of /spl les/ 4.0 dB for frequencies from 11.7-12.2 GHz.     

Linear microwave amplification with Gunn oscillators

Linear microwave amplifiers with continuous power outputs of 100 mW have been constructed utilizing the frequency-independent negative conductance observed externally in Gunn oscillators. This negative conductance is exhibited only in samples containing propagating dipole layers, in other words,n_{0} . Lmust be larger than 10¹²cm^-2for n-GaAs. The output power obtainable from this amplifier is substantially larger than that from a subcritically doped GaAs amplifier (n_{0} . L < 10^{12}cm^-2) becausen_{0} . Lcan be increased. Power output and efficiency are discussed in terms of n0andL. The upper-frequency limit for amplification is determined by the time the domain takes to readjust itself after a change of external voltage which leads to an upper limit for thef. Lproduct (about 10⁸cm/s). The essential feature of the amplifier circuit is to provide both a short circuit at the Gunn oscillation frequency and a broadband circuit at the signal frequency. An average gain of 3 dB was exhibited from 5.5 GHz to 6.5 GHz. Gain compression of 1 dB occurred at 60 mW output power with 9 dB gain, while the noise figure was about 19 dB.     

（英）D波段InP基高增益、低噪声放大芯片的设计与实现

利用90-nm InAlAs/InGaAs/InP HEMT工艺设计实现了两款D波段（110~170 GHz）单片微波集成电路放大器。两款放大器均采用共源结构,布线选取微带线。基于器件A设计的三级放大器A在片测试结果表明：最大小信号增益为11.2 dB@140 GHz,3 dB带宽为16 GHz,芯片面积2.6×1.2 mm2。基于器件B设计的两级放大器B在片测试结果表明：最大小信号增益为15.8 dB@139 GHz,3dB带宽12 GHz,在130~150 GHz频带范围内增益大于10 dB,芯片面积1.7×0.8 mm2,带内最小噪声为4.4 dB、相关增益15 dB@141 GHz,平均噪声系数约为5.2 dB。放大器B具有高的单级增益、相对高的增益面积比以及较好的噪声系数。该放大器芯片的设计实现对于构建D波段接收前端具有借鉴意义。     

Integrated Multilayered On-Chip Inductors for Compact CMOS RFICs and Their Use in a Miniature Distributed Low-Noise-Amplifier Design for Ultra-Wideband Applications

A novel multilayered vertically integrated inductor structure is developed for miniature CMOS RF integrated circuits, and its properties are investigated. The effect of mutual inductance both within and between adjacent multilayer inductors is also studied. A distributed low noise amplifier is designed by incorporating this novel inductor structure in a standard JAZZ 0.18-$mu$m RF/mixed signal CMOS process, demonstrating the significance of the proposed multilayered inductors in CMOS circuit miniaturization. The three-stage distributed amplifier occupies just 288$,times,$291 $mu$m or 0.08 mm $^{2}$ of die area, making it the smallest distributed amplifier reported to date. The circuit exhibits a relatively flat gain of 6 dB from 3.1 to 10.6 GHz with less than 0.5-dB ripple, with excellent input and output match of less than ${-}$ 12 and ${-}$25 dB, respectively. The noise figure is less than 5 dB to 14 GHz with only 2.7 dB across 8–10 GHz, while the power consumption is approximately 22 mW.      

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.     

GaAs Monolithic Low-Power Amplifiers with RC Parallel Feedback (Short Paper)

GaAs monolithic broad-band low-power-dissipated amplifiers with inductive/resistive load and RC parallel feedback circuits have been developed. An inductive load amplifier provides a gain of 8 dB, a 3-dB bandwidth of 2.5 GHz, and a noise figure of 2.7 dB at 1 GHz with less than + 1-V supply voltage and very low-power dissipation of 20 mW. A resistive load two-stage amplifier provides a gain of 15 dB and a 3-dB bandwidth of 2 GHz. Input and output reflection coefficients at 1 GHz are -13 dB and -21 dB, respectively.     

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.     

Performance characteristics of a 300-GHz radiometer and some atmospheric attenuation measurements

A 300-GHz Dicke-type superheterodyne radiometer receiver was used for measurements of atmospheric attenuation of electromagnetic waves over an open path at frequencies near 300 GHz. The average measured values of horizontal attenuation at 304 GHz and 316 GHz, presumably due to atmospheric water vapor absorption, were, respectively, 3.35 dB/km and 5.55 dB/km per g/m³of water vapor density. Absorption variations at 304 GHz with respect to water vapor density were shown in the measured results. The variation of the effective zenith sky temperature with respect to atmospheric water vapor density was also determined. The minimum detectable temperature difference(Delta T)_{min}, was obtained by measuring the rms value of noise in the receiver output. The best value achieved was3.16degK. Based on this result, the receiver noise figure and the mixer conversion loss were determined indirectly. The results were 31.4 dB and 22.9 dB, respectively. A blackbody radiation source served to calibrate the radiometer.     

Development of Integrated Broad-Band CMOS Low-Noise Amplifiers

This paper presents a systematic design methodology for broad-band CMOS low-noise amplifiers (LNAs). The feedback technique is proposed to attain a better design tradeoff between gain and noise. The network synthesis is adopted for the implementation of broad-band matching networks. The sloped interstage matching is used for gain compensation. A fully integrated ultra-wide-band 0.18-mum CMOS LNA is developed following the design methodology. The measured noise figure is lower than 3.8 dB from 3 to 7.5 GHz, resulting in the excellent average noise figure of 3.48 dB. Operated on a 1.8-V supply, the LNA delivers 19.1-dB power gain and dissipates 32 mW of power. The gain-bandwidth product of the UWB LNA reaches 358 GHz, the record number for the 0.18-m CMOS broad-band amplifiers. The total chip size of the CMOS UWB LNA is 1.37 times 1.19 mm².     

A 40-GHz Low-Noise Amplifier With a Positive-Feedback Network in 0.18-$mu{hbox{m}}$ CMOS

A novel circuit topology for a CMOS millimeter-wave low-noise amplifier (LNA) is presented in this paper. By adopting a positive-feedback network at the common-gate transistor of the input cascode stage, the small-signal gain can be effectively boosted, facilitating circuit operations at the higher frequency bands. In addition, $LC$ ladders are utilized as the inter-stage matching for the cascaded amplifiers such that an enhanced bandwidth can be achieved. Using a standard 0.18-$mu{hbox{m}}$ CMOS process, the proposed LNA is implemented for demonstration. At the center frequency of 40 GHz, the fabricated circuit exhibits a gain of 15 dB and a noise figure of 7.5 dB, while the return losses are better than 10 dB within the 3-dB bandwidth of 4 GHz. Operated at a 1.8-V supply, the LNA consumes a dc power of 36 mW.      

X- and Ku-band amplifiers with GaAs Schottky-barriers field-effect transistors

During recent years significant progress has been made in GaAs technology and the GaAs Schottky-barrier field-effect transistor now shows outstanding microwave gain and noise properties. Two experimental microwave amplifiers demonstrate that the device is very well suited for broad-band applications and that large bandwidth in the X- and Ku-band can be obtained with simple circuits. The first of the two three-stage amplifiers realized was optimized with respect to noise and a noise figure of 3.8 dB was obtained at 8 GHz; the maximum gain is 17.5 dB at 8.3 GHz and the 3-dB bandwidth is 1.3 GHz. The second amplifier has a maximum gain of 11.5 dB at 11.5 GHz. The gain is greater than 8.5 dB in the range 9.5-14.3 GHz.     

30-GHz Low-Noise Performance of 100-nm-Gate-Recessed n-GaN/AlGaN/GaN HEMTs

We demonstrate a 100-nm-gate-recessed n-GaN/AlGaN/GaN high-electron mobility transistor (HEMT) with low-noise properties at 30 GHz. The recessed GaN HEMT exhibits a low ohmic-contact resistance of 0.28 $Omega cdot hbox{mm}$ and a low gate leakage current of 0.9 $muhbox{A/mm}$ when biased at $V_{rm GS} = -hbox{3} hbox{V}$ and $V_{rm DS} = hbox{10} hbox{V}$. At the same bias point, a minimum noise figure of 1.6 dB at 30 GHz and an associated gain of 5 dB were achieved. To the best of our knowledge, this is the best noise performance reported at 30 GHz for gate-recessed AlGaN/GaN HEMTs.      

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