Roger Tsai

A W-band InAs/AlSb low-noise/low-power amplifier

The first W-band antimonide based compound semiconductor low-noise amplifier has been demonstrated. The compact 1.4-mm/sup 2/ three-stage co-planar waveguide amplifier with 0.1-/spl mu/m InAs/AlSb high electron mobility transistor devices is fabricated on a 100-/spl mu/m GaAs substrate. Minimum noise-figure of 5.4dB with an associated gain of 11.1 dB is demonstrated at a total chip dissipation of 1.8 mW at 94 GHz. Biased for higher gain, 16/spl plusmn/1 dB is measured over a 77-103 GHz frequency band.

A 2 Watt, Sub-dB Noise Figure GaN MMIC LNA-PA Amplifier with Multi-octave Bandwidth from 0.2-8 GHz

This paper reports on a 0.2-8 GHz high dynamic range GaN MMIC LNA-PA which achieves sub-dB noise figure and a PldB of 2 watts. The GaN MMIC utilizes a 0.2 mum AlGaN/GaN-SiC HEMT technology with an fT ~75 GHz. At high power bias (15 V/400 mA), the MMIC amplifier achieves sub-dB NF ~0.7-0.9 dB over a 2-8 GHz band. At low bias(12 V, 200 mA), the amplifier achieves ~0.5dB over the same band. This is believe to be the lowest NF reported for a multi-octave MMIC amplifier in the S-and C-band frequency range. In addition, the amplifier obtains ultra high linearity with an OIP3 of 43.2-46.5 dBm and P1 dB of 32.8-33.2 dBm (2 watts) over a 2-6 GHz bandwidth. The PAE at P1 dB is ~28.6-31%. The Psat is 34.2 dBm with 39% PAE @ 2 GHz. To our knowledge, this is the first report of a multi-octave MMIC amplifier with sub-dB NF and a pout >2 Watt.

An indium phosphide MMIC amplifier for 180-205 GHz

This paper describes a high-performance indium phosphide (InP) monolithic microwave integrated circuit (MMIC) amplifier, which has been developed for application in radioastronomy and imaging-array receivers. Implemented using coplanar waveguide, the six-stage amplifier exhibits 15 db gain, 10 dB input and output return loss, and low noise figure over the 180-205 GHz frequency range. Only one design pass was needed to obtain excellent agreement between the predicted and measured characteristics of the circuit, a unique achievement in this frequency band. The circuit is also the first 180-205 GHz amplifier designed for and successfully fabricated using TRWs standard 0.1-/spl mu/m InP HEMT process.

A 1–25 GHz GaN HEMT MMIC Low-Noise Amplifier

This letter presents an ultra-wideband low noise amplifier (LNA) using gallium-nitride (GaN) high-electron mobility transistors (HEMT) technology. A -3 dB bandwidth of 1-25 GHz with 13 dB peak power gain is achieved using a modified resistive-feedback topology. To obtain such a wide bandwidth, several bandwidth enhancement techniques are utilized. An inductor connected to the source of the input transistor ensures good input matching (|S11| <; -9 dB) across the entire bandwidth. The shunt feedback loop and the inductive source degeneration minimize all the required inductor values. This GaN HEMT LNA is believed to have the widest bandwidth among all GaN HEMT monolithic microwave integrated circuit (MMIC) LNAs reported to date. With 3.3 dB minimum noise figure (F), 33.5 dBm maximum output-referred third-order intercept point (OIP3), 20 dBm maximum output-referred 1 dB compression point (Output P1 dB), this MMIC amplifier is comparable in performance to distributed amplifiers (DAs) but with significantly lower power consumption and smaller area.

1-Watt Conventional and Cascoded GaN-SiC Darlington MMIC Amplifiers to 18 GHz

A 0.2 mum T-gate GaN-SiC HEMT technology with fT-70 GHz are used to achieve GaN Darlington MMIC Amplifiers with bandwidths up to 18 GHz. Both conventional Darlington and Cascoded-Darlington feedback designs were fabricated and measured. The Darlington Cascode obtains 14.7 dB gain and a bandwidth of 0.05-12.3 GHz. The conventional Darlington obtains 11 dB gain and a record 0.05-18.7 GHz multi-decade bandwidth for a GaN Darlington. These are the highest BWs reported for GaN Darlington MMIC amplifiers. In addition, P1dB ~1 Watt and > 40 dBm OIP3 was obtained beyond 4 GHz. To our knowledge, these results represent the widest bandwidths so far demonstrated for fully monolithic GaN Darlington MMICs.

AlGaN/GaN HEMTs - operation in the K-band and above

Reports on the power and microwave noise performance of AlGaN/GaN high electron-mobility transistors (HEMTs) at frequencies f>18 GHz (K- and Ka-bands). At 20 GHz, a record continuous-wave output power of 1.6 W has been achieved on an eight-finger 500-/spl mu/m total gate-periphery device. At 29 GHz, a 120-/spl mu/m gate-periphery device showed a pulsed output density of 1.6 W/mm with an associated gain of 6.7 dB and power-added efficiency of 26%. Minimum noise figure of 1.5 dB has been achieved on a 0.2 /spl mu/m /spl times/ 200 /spl mu/m device at 26 GHz. The data demonstrate the viability of AlGaN/GaN HEMTs for high-frequency power and low-noise amplifier applications.

A Low Power/Low Noise MMIC Amplifier for Phased-Array Applications using InAs/AlSb HEMT

In this paper, we present a two-stage low-power/low-noise MMIC amplifier. At 10-GHz, the amplifier demonstrates high gain (~18-dB) and moderate noise figure (<1.8-dB) at a total DC power consumption of only 1.38-mW. The ultra-low power MMIC amplifier utilizes InAs/AlSb metamorphic HEMT technology, which enables a low-power/low-noise operating point of 0.15-V and 40-mA/mm for each gain stage, considerably lower than either InP or GaAs low-power bias points. The compact design (1.6times2.6-mm2) is realized in coplanar waveguide architecture (CPW), including CPW spiral inductors

A Q-band low phase noise monolithic AlGaN/GaN HEMT VCO

A Q-band 40-GHz GaN monolithic microwave integrated circuit voltage controlled oscillator (VCO) based on AlGaN/GaN high electron mobility transistor technology has been demonstrated. The GaN VCO delivered an output power of +25dBm with phase noise of -92dBc/Hz at 100-KHz offset, and -120dBc/Hz at 1-MHz offset. To the best of our knowledge, this represents the state-of-the-art for GaN VCOs in terms of frequency, output power, and phase noise performance. This work demonstrates the potential for the use of GaN technology for high frequency, high power, and low phase noise frequency sources for military and commercial applications

High performance and high reliability InP HEMT low noise amplifiers for phased-array applications

This paper describes the development of a Q-band low noise amplifier unit using a 0.1 /spl mu/m InP HEMT MMICs that has been demonstrated with high RF performance and high reliability over a frequency band from 43.5 to 45.5 GHz at Northrop Grumman Space Technology (NGST). The InP HEMT LNAs with high RF performance and high reliability are crucial for the advanced phased-array applications. The module demonstrates superior performance with gain greater than 30.1 dB and noise figure less than 3.2 dB over the frequency band of 43.5 to 45.5 GHz. The InP HEMT technology has an activation energy of 1.9 eV and mean-time-to-failure of 10/sup 8/ hours at T/sub junction/ of 125/spl deg/C and these MMICs further demonstrate the readiness of NGSTs 0.1 /spl mu/m InP HEMT MMICs technology for the advanced phased-array applications.

A 110-GHz AlSb/InAs MMIC amplifier

We describe the first demonstration of a W-band amplifier using antimonide based compound semiconductor (ABCS) device technology. The three stage CPW MMIC uses two finger 0.1-/spl mu/m AlSb/InAs HEMT with a total periphery of 40 micron per device. Biased at a total MMIC dissipation of 3.7-m W the amplifier demonstrates 11/spl plusmn/ 1 dB gain over a 80-110 GHz bandwidth. When biased at total MMIC dissipation of 9.0 mW, the amplifier demonstrates 15/spl plusmn/ 1 dB gain over 80-100 GHz bandwidth.