Joshua Bergman

An ultra-low power InAs/AlSb HEMT Ka-band low-noise amplifier

The first antimonide-based compound semiconductor (ABCS) MMIC, a Ka-Band low-noise amplifier using 0.25-/spl mu/m gate length InAs/AlSb metamorphic HEMTs, has been fabricated and characterized on a 75 /spl mu/m GaAs substrate. The compact 1.1 mm/sup 2/ three-stage Ka-band LNA demonstrated an average of 2.1 dB noise-figure between 34-36 GHz with an associated gain of 22 dB. The measured dc power dissipation of the ABCS LNA was an ultra-low 1.5 mW per stage, or 4.5 mW total. This is less than one-tenth the dc power dissipation of a typical equivalent InGaAs/AlGaAs/GaAs HEMT LNA. Operation with degraded gain and noise figure at 1.1 mW total dc power dissipation is also verified. These results demonstrate the outstanding potential of ABCS HEMT technology for mobile and space-based millimeter-wave applications.

InAs/AlSb HEMT and Its Application to Ultra-Low-Power Wideband High-Gain Low-Noise Amplifiers

Two antimonide-based compound semiconductor (ABCS) microstrip monolithic microwave integrated circuits (MMICs), i.e., single- and three-stage ultra-low-power wideband 0.3-11-GHz low-noise amplifiers (LNAs) using 0.1-mum gate-length InAs/AlSb metamorphic high electron-mobility transistors (HEMTs), have been fabricated and characterized on a GaAs substrate. The single-stage wideband LNA demonstrated a typical associated gain of 16 dB (0.3-11 GHz) with less than a 1.7-dB noise figure (2-11 GHz) at 5-mW dc power dissipation, and the three-stage wideband LNA demonstrated a typical associated gain of 30 dB (0.3-11 GHz) with less than a 2.6-dB noise figure (2-11 GHz) at 7.5-mW dc power dissipation. We believe these wideband LNA MMICs demonstrate the lowest dc power consumption with the highest gain-bandwidth product of any MMIC to date. These results demonstrate the outstanding potential of ABCS HEMT technology for ultra-low-power wideband applications

An ultra-low power InAs/AlSb HEMT W-band low-noise amplifier

An antimonide-based compound semiconductor (ABCS) microstrip MMIC, a W-Band low-noise amplifier using 0.2-μm gate length InAs/AlSb metamorphic HEMTs, has been fabricated and characterized on a 50 μm GaAs substrate. The compact 1.2 mm 2 five-stage W-band LNA demonstrated a 3.9 dB noise-figure at 94 GHz with an associated gain of 20.5 dB. The measured dc power dissipation of the ABCS LNA was an ultra-low 1.2mW per stage, or 6.0 mW total which is less than one-tenth the dc power dissipation of a typical equivalent InGaAs/AlGaAs/GaAs HEMT LNA. Operation with degraded gain and noise figure at 3.5 mW total de power dissipation is also verified. These results demonstrate the outstanding potential of ABCS HEMT technology for mobile and space-based millimeter-wave applications.

High Performance Mixed Signal and RF Circuits Enabled by the Direct Monolithic Heterogeneous Integration of GaN HEMTs and Si CMOS on a Silicon Substrate

In this work we present recent results on the direct heterogeneous integration of GaN HEMTs and Si CMOS on a silicon substrate. GaN HEMTs whose DC and RF performance are comparable to GaN HEMTs on SiC substrates have been achieved. As a demonstration vehicle we designed and fabricated a GaN amplifier with pMOS gate bias control circuitry (a current mirror) and heterogeneous interconnects. This simple demonstration circuit is a building block for more advanced RF, mixed signal and power conditioning circuits, such as reconfigurable or linearized PAs with in-situ adaptive bias control, high power digital-to-analog converters (DACs), driver stages for on-wafer optoelectronics, and on-chip power distribution networks.

InAs/AlSb HFETs with f τ and f max above 150 GHz for low-power MMICs

Very low-power InAs/AlSb HFETs with excellent RF performance are reported. These metamorphic HFETs on GaAs substrates combine high microwave g/sub m/ of at least 1.1 S/mm with low parasitic resistances to offer simultaneous measured f/sub /spl tau// and f/sub max/ values of 160 GHz for both figures of merit. This performance is obtained at a drain bias voltage of only 0.35 V for an HFET with a 0.25-/spl mu/m gate length. The high current gain (f/sub /spl tau//) is attributable to the improved charge control due to scaling of the barrier thickness to 180 /spl Aring/. The maximum power gain (f/sub max/) depends on both g/sub m/ and the HFET output conductance, which is fundamentally limited by the low breakdown voltage gap of the InAs channel (E/sub g/ = 0.36 eV).

Low-voltage, high-performance InAs/AlSb HEMTs with power gain above 100 GHz at 100 mV drain bias

Ultra-low power circuits require transistors with usable RF gain at low bias voltages and currents. In the present paper, we report 100 nm gate-length InAs/AlSb HEMTs with f/sub /spl tau// and f/sub max/ both exceeding 100 GHz at a mere 100 mV of drain bias. The devices also show excellent peak value for f/sub /spl tau// of 235 GHz and, to the best of our knowledge, a record f/sub max/ of 235 GHz at a higher drain bias of 300 mV.

Ultra-Low-Power Wideband High Gain InAs/AlSb HEMT Low-Noise Amplifiers

Two antimonide-based compound semiconductor (ABCS) microstrip MMICs, single-stage and three-stage ultra-low-power wideband 0.01-11 GHz low-noise amplifiers using 0.1-mum gate length InAs/AlSb metamorphic HEMTs, have been fabricated and characterized on a GaAs substrate. From 0.3-11 GHz, the single-stage wideband LNA demonstrated a typical associated gain of 16 dB with less than 1.7 dB noise figure (2-11 GHz) at 5mW DC power dissipation, and the three-stage wideband LNA demonstrated a typical associated gain of 30 dB with less than 2.6 dB noise figure (2-11 GHz) at 7.5mW DC power dissipation. We believe these low noise amplifier MMICs demonstrate the lowest DC power consumption with the highest gain-bandwidth product of any MMIC to date. These results demonstrate the outstanding potential of ABCS HEMT technology for ultra-low-power wideband applications

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-mum 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

Ultra-Wideband Ultra-Low-DC-Power High Gain Differential-Input Low Noise Amplifier MMIC Using InAs/AlSb HEMT

This paper reports an ultra-wideband ultra-low-DC power high gain MMIC low noise amplifier (LNA) with differential RF input using 0.1-mum gate length InAs/AlSb metamorphic HEMTs, fabricated and characterized on a GaAs substrate. For testing purpose and for generating a differential RF input, a 3-12 GHz wideband on-chip MMIC balun is connected to the differential input. Even with the loss of the balun included, the differential amplifier demonstrated 4 dB typical noise figure with associated gain of 22 dB from 3-12 GHz at a low DC dissipation of 23 mW. Additionally, a single-ended LNA, which the differential LNA is based on, is also fabricated for evaluation. The single-ended LNA demonstrated 1.5 dB typical noise figure with associated gain of 25 dB from 1-16 GHz at a low DC dissipation of 16 mW

Design and characteristics of strained InAs/InAlAs composite-channel heterostructure field-effect transistors

We report composite-channel heterostructure field-effect transistors (HFETs) with an InAs channel and an In0.9Al0.1As subchannel. The HFETs are grown on antimonide buffer layers. Two composite-channel structures with different planar Te doping schemes are designed, fabricated, and characterized. High radio-frequency transconductances of above 0.9 S/mm and ∼55GHz current gain cutoff frequencies are achieved in devices with 500 nm gates. Planar Te doping in the buffer layers reduces the high kink-effect currents otherwise found in InAs/AlSb HFETs, an effect which can be attributed to either increased breakdown field in the In0.9Al0.1As subchannel or to suppression of hole blocking in the buffer. The present limitations to device performance and suggested approaches for their elimination are discussed.