P.H. Liu

First Demonstration of Amplification at 1 THz Using 25-nm InP High Electron Mobility Transistor Process

We report the first ever terahertz monolithic integrated circuit amplifier based on 25-nm InP high electron mobility transistor (HEMT) process demonstrating amplification at 1 THz (1000 GHz) with 9-dB measured gain at 1 THz. This milestone was achieved with a 25-nm InP HEMT transistor, which exhibits 3.5-dB maximum available gain at 1 and 1.5 THz projected fMAX.

Low Noise Amplification at 0.67 THz Using 30 nm InP HEMTs

In this letter, low noise amplification at 0.67 THz is demonstrated for the first time. A packaged InP High Electron Mobility Transistor (HEMT) amplifier is reported to achieve a noise figure of 13 dB with an associated gain greater than 7 dB at 670 GHz using a high fMAX InP HEMT transistors in a 5 stage coplanar waveguide integrated circuit. A 10-stage version is also reported to reach a peak gain of 30 dB. These results indicate that InP HEMT integrated circuits can be useful at frequencies approaching a terahertz.

0.10 /spl mu/m graded InGaAs channel InP HEMT with 305 GHz f/sub T/ and 340 GHz f/sub max/

We report here 305 GHz f/sub T/, 340 GHz f/sub max/, and 1550 mS/mm extrinsic g/sub m/ from a 0.10 /spl mu/m In/sub x/Ga/sub 1-x/As/In/sub 0.62/Al/sub 0.48/As/InP HEMT with x graded from 0.60 to 0.80. This device has the highest f/sub T/ yet reported for a 0.10 /spl mu/m gate length and the highest combination of f/sub T/ and f/sub max/ reported for any three-terminal device. This performance is achieved by using a graded-channel design which simultaneously increases the effective indium composition of the channel while optimizing channel thickness.<<ETX>>

High-performance in W-band monolithic pseudomorphic InGaAs HEMT LNA's and design/analysis methodology

High-performance W-band monolithic one- and two-stage low noise amplifiers (LNAs) based on pseudomorphic InGaAs-GaAs HEMT devices have been developed. The one-stage amplifier has a measured noise figure of 5.1 dB with an associated gain of 7 dB from 92 to 95 GHz, and the two-stage amplifier has a measured small signal gain of 13.3 dB at 94 GHz and 17 dB at 89 GHz with a noise figure of 5.5 dB from 91 to 95 GHz. An eight-stage LNA built by cascading four of these monolithic two-stage LNA chips demonstrates 49 dB gain and 6.5 dB noise figure at 94 GHz. A rigorous analysis procedure was incorporated in the design, including accurate active device modeling and full-wave EM analysis of passive structures. The first pass success of these LNA chip designs indicates the importance of a rigorous design/analysis methodology in millimeter-wave monolithic IC development. >

Demonstration of a 0.48 THz Amplifier Module Using InP HEMT Transistors

In this letter, we present an amplifier module operating at a frequency of 0.48 THz. This represents almost a 50% increase in solid-state amplifier operating frequency compared to prior state of the art, and is the highest reported amplifier to date. The amplifier demonstrates a peak gain of 11.7 dB measured in a waveguide split-block housing. Sub 50-nm InP HEMT transistors with an estimated f MAX > 1 THz are used to achieve this level of performance. The five stage amplifier is realized in coplanar waveguide, and uses monolithically integrated dipole probes to couple the chip from the WR 2.2 waveguide.

High-power V-band pseudomorphic InGaAs HEMT

The authors present the DC and RF power performance of planar-doped channel InGaAs high-electron-mobility transistors (HEMTs). The planar-doped channel (PDC) pseudomorphic GaAs HEMT with 400 mu m of gate width exhibited an output power of 184 mW, corresponding to 460 mW/mm, with 4.6-dB saturation gain and 25% power-added efficiency at 55 GHz. Although higher power density is possible, the authors have designed the device to operate at less than 500 mW/mm for thermal and reliability reasons. Devices with unit gate finger widths ranging from 30 to 50 mu m were fabricated and characterized, with no performance degradation observed from using the longer gate fingers.<<ETX>>

Millimeter-wave, cryogenically-coolable amplifiers using AlInAs/GaInAs/InP HEMTs

The cryogenic performance of AlInAs/GaInAs/InP 0.1- mu m high-electron-mobility transistors (HEMTs) is reported. Collapse-free DC operation is observed down to the ambient temperature of 18 K. The application of these devices to Q- and E-band low-noise, cryogenically coolable amplifiers is demonstrated. The measured noise temperature of 15 K (noise figure of 0.2 dB) for a multistage 40-45-GHz amplifier with 33 dB of gain at the ambient of 18 K is in close agreement with the prediction of a simple noise model. A very low power consumption per stage of less than 1 mW is recorded. The noise temperature of the E-band cryogenic amplifier is less than 47 K at 70 GHz, demonstrating that the performance of HEMT receivers is now competitive with that of SIS (superconductor-insulator-superconductor) receivers in the 3-mm wavelength atmospheric window.<<ETX>>

Demonstration of a S-MMIC LNA with 16-dB Gain at 340-GHz

In this paper, an amplifier with a significant amount of gain is demonstrated at sub-millimeter wave frequencies (f > 300-GHz) for the first time. The three stage amplifier uses advanced InP HEMT transistors to realize 16-dB gain at 340-GHz and > 20 dB gain at 280-GHz. The amplifier demonstrates > 100 GHz of bandwidth with gain > 10 dB. This paper demonstrates that full WR-3 waveguide band (220-325 GHz) InP HEMT amplifiers are currently possible and that current device capabilities enable operation well into the sub-millimeter wave regime.

A 140-GHz monolithic low noise amplifier

This paper presents the development of a 140-GHz monolithic low noise amplifier (LNA) using 0.1-/spl mu/m pseudomorphic InAlAs-InGaAs-InP low noise HEMT technology. A two-stage single-ended 140-GHz monolithic LNA has been designed, fabricated and tested. It exhibits a measured small signal gain of 9 dB at 142 GHz, and more than 5-dB gain from 138-145 GHz. This is the highest frequency monolithic amplifier ever reported using three terminal devices. >

Demonstration of Sub-Millimeter Wave Fundamental Oscillators Using 35-nm InP HEMT Technology

In this letter, 254-, 314-, and 346-GHz fundamental oscillators are demonstrated. These are the highest frequency oscillators using three-terminal devices reported to date. The performance is enabled through a 35-nm InP HEMT process with maximum frequency of oscillation (fmax) of 600GHz. These first-pass designs use coplanar waveguide (CPW) technology and include on-chip resonator and output matching. The maximum available gain (MAG) of these devices has been measured to be ~9.6dB at 200GHz