Integrated Circuits Based on 300 GHz fT Metamorphic HEMT Technology for Millimeter-Wave and Mixed-Signal Applications

Advanced circuits based on metamorphic HEMT (MHEMT)technologies on 4 ”GaAs substrates for both millimeter-wave,and mixed- signal applications are presented.Extrinsic cut-off frequencies of ft =293 GHz and fmax =337 GHz were achieved for a 70 nm gate length metamorphic HEMT echnology.The MMIC process obtains high yield on transistor and circuit level.Single-stage low-noise amplifiers demonstrate a small signal gain of 13 dB and a noise figure of 2.8 dB at 94 GHz.An amplifier MMIC developed for D-Band operation features a gain of 15 dB at 160 GHz.The achieved results are comparable to state- of-the-art InP-based HEMT technologies.In order to realize 80 Gbit/s digital circuits,a process with 100 nm gate length enhancement type HEMTs with a transit frequency of 200 GHz is used.Three metalization layers are available for interconnects.The parasitic capacitance of the interconnects is kept low by using BCB and plated air bridge technology.Based on this process,static and dynamic frequency dividers achieve a maximu toggle frequency of 70 GHz and 108 GHz,respectively

A 183 GHz metamorphic HEMT low-noise amplifier with 3.5 dB noise figure

This paper presents a 183 GHz low-noise amplifier (LNA), designed primarly for water vapor detection in atmosphere. The LNA requirements were defined by MetOp Second Generation (MetOp-SG) Microwave Sounder, Microwave Imager and Ice Cloud Imager instruments. MetOp-SG is the European contribution to operational meteorological observations from polar orbit. This LNA advances the current state-of-the-art for the InGaAs metamorphic high electron mobility transistor (mHEMT) technology. The five-stage common-source MMIC amplifier utilizes transistors with a gate length of 50 nm. On-wafer measurements show a noise figure of 3.5 dB at the operative frequency, about 1 dB lower than previously reported mHEMT LNAs, and a gain of 24±2 dB over the bandwidth 160-200 GHz. The input and output matching are -11 dB and -10 dB, respectively. Moreover, the DC power dissipation at the optimal bias for noise is as low as 24 mW

Frequency Multiplier and Mixer MMICs Based on a Metamorphic HEMT Technology Including Schottky Diodes

This paper reports on the monolithic integration of layout-optimized Schottky diodes realized in an established 50-nm gate-length metamorphic high-electron-mobility transistor technology for use in multifunctional nonlinear circuits. The suitability of the realized Schottky diodes is demonstrated by a broadband millimeter-wave I/Q-mixer (In-phase/Quadrature) and local oscillator (LO) chain comprising two power amplifiers and a frequency tripler, fabricated on monolithic microwave integrated circuits (MMICs). Both circuits are based on an anti-parallel Schottky diode topology. The subharmonically-pumped I/Q-mixer covers an RF (radio frequency) and IF (intermediate frequency) range of at least 75 GHz to 110 GHz and 0.5 GHz to 15 GHz, respectively. The single-sideband conversion loss is between 14 dB and 16 dB across most of the entire RF and IF bands. The core of the LO chain consists of a frequency tripler (multiplier by three) and features a bias-adjustable output power with almost constant conversion efficiency and a control range of more than 8 dB. The fully-integrated LO chain MMIC matches the needs of the presented I/Q-mixer and exhibits an average output power of 16.3 dBm with a covered frequency range of 38 GHz to 60 GHz. The unwanted harmonics are suppressed by at least −25.9 dBc below the third harmonic for the entire frequency range and better than −32.1 dBc for most part of the band. Thus, the mixer and tripler MMICs demonstrate state-of-the-art performance with regards to, e.g., covered bandwidth, output power, harmonic suppression, or 1 dB compression point

Low noise amplifiers for MetOp-SG

We present low-noise amplifiers (LNA) that have been developed in the framework of two pre-qualification ESA projects for frequencies between 54 and 229 GHz for the METOP-SG satellite program. The main goal of these satellites is water vapor detection in atmospheric science and weather forecasting which advances the current state of the art for the metamorphic high electron mobility transistor (mHEMT) technology. The MMIC amplifiers are based on the In0.52Al0.48As/In0.8Ga0.2As/In0.53Ga0.47As heterostructure and utilize transistors with a gate length of 50 nm. On-wafer measurements will be presented for all frequency bands as well as results of packaged LNAs

Lateraler und vertikaler elektrischer Transport in Halbleiterheterostruktur-Bauelementen mit 2D-Elektronengasen

Als Voraussetzung für den gezielten Entwurf von Halbleiterschichtsystemen und für die Auswertung experimenteller Ergebnisse wurde ein Computerprogramm zurBerechnung des Potentialverlaufes und der Ladungsverteilung in Halbleiterheterostrukturen entwickelt. Durch den Vergleich von Hall-Messungen an Si-$\delta$-dotierten AlGaAs/GaAs-Heterostrukturen mit selbstkonsistenten Rechnungen konnten für die Anwendung wichtige Parameter des AlGaAs/GaAs-Materialsystems bestimmt werden. Abhängig vom AlAs-Gehalt wurden für nahezu den gesamten Kompositionsbereich des AlGaAs die Bandkantensprünge und die energetischen Lage der DX-Zentren mit einer hohen Genauigkeit ermittelt. Neben dem lateralen Magnetotransport wurde der vertikale elektrische Transport anhand von Ladungs-Injektions-(CHINT) und Tunneltransistoren untersucht. Es wurde erstmals ein Verfahren zur ohmschen Kontaktierung zweidimensionaler Elektronengase (2DEGs) ohne Einlegierung der Kontakte in Kombination mit selektivem Ätzen entwickelt. Auf diese Weise steht nun eine Technologie zur Verfügung, ein 2DEG isoliert von tieferliegenden leitenden Schichten zu kontaktieren. Ausgehend von diesen nichtlegierten Kontakten wurden CHINTs hergestellt, in denen ein 2DEG als Elektronenemitter über eine Potentialbarriere verwendet wird. Es konnten bei Raumtemperatur hohe Steilheiten von bis zu 700mS/mm, wenn auch bei relativ geringen Stromverstärkungen, realisiert werden. Neben dem vertikalen Stromtransport aufgrund von Elektronenemission über eine Potentialbarriere wurde der Stromtransport aufgrund von Tunnelprozessen durch Barrieren hindurch untersucht. Als neuer Ansatz wurden Bauelemente basierend auf Tunnelprozessen zwischen 2DEGs mit Hilfe von nichtlegierten Kontakte hergestellt und untersucht. 2D-2D-Tunneldioden im InGaAs/InP-Materialsystem zeigten unterhalb 150K ausgeprägte Resonanzeffekte. Ein neuartiger 2D-2D-Tunneltransistor, bestehend aus einem 2DEG mit Source- und Drain-Kontakten sowie einem zweiten durch Tunnelprozesse angekoppelte 2DEG zeigtesehr interessante, multifunktionale Eigenschaften . Aus der vorliegenden Arbeit sind Patentanmeldungen hervorgegangen für nichtlegierte ohmsche Kontakte, für einen2D-2D-Tunneltransistor sowie eine im langwelligen Infrarot arbeitende Leucht- und Laserdiode, die zugleich als optischer Detektor verwendbar ist

D-band low-noise amplifier MMIC with 50 % bandwidth and 3.0 dB noise figure in 100 nm and 50 nm mHEMT technology

We present the development of a wideband lownoise amplifier MMIC in the D-band with a smart combination of coplanar transmission lines and active devices to minimize noise figure. The identical three-stage LNA has been realized in metamorphic HEMT technologies with 100 nm and 50 nm gate length. The 50 nm LNA MMIC achieves a linear gain of 30.8 dB together with a bandwidth of 67 GHz up to 164 GHz and a noise figure of 3.0 dB. The performance of 100 nm LNA is slightly worse

Investigation of compact power amplifier cells at THz frequencies using InGaAs mHEMT technology

In this paper a design approach for compact power amplifier cells at frequencies around and above 300 GHz is presented, using a 35nm InGaAs mHEMT technology. Up to 8-finger common-source (CS) and cascode devices are developed based on 2-finger multiport models without feeding structures. Two power amplifier MMICs are presented with more than 15 dB measured small-signal gain between 290 – 335 GHz. 6.8 – 8.6-dBm output power is reported for the frequency range of 280 – 320 GHz, which is state-of-the-art for InGaAs based mHEMT technologies at these frequencies. Due to the compact CS and cascode cells, the required width of the PA core is significantly reduced, achieving high output power levels per required chip width and enabling further parallelization

HEMT large-signal integral transform model including trapping and impact ionization

A new large-signal FET model is proposed which simultaneously covers trapping, impact ionization, breakdown and thermal effects in an effective analytical channel current formulation. Drain current and charge functions are described using an integral transform of conductances and capacitances. An InAlAs/InGaAs mHEMT extraction example demonstrates a good simultaneous prediction of DC, small-signal and large signal performance of the device in spite of different low frequency dispersion effects which may be related to trapping and impact ionization effects in the device