William L. Jones

A family of 2-20 GHz broadband low noise AlGaAs HEMT MMIC amplifiers

The authors describe the technology development leading to a family of high-electron-mobility transistor (HEMT) monolithic low-noise amplifiers (LNAs), and present modeled and measured performance data on LNAs covering the 2-20 GHz frequency band. These amplifiers achieve noise figures comparable to their counterpart in hybrid HEMT technology. The amplifiers are configured in a cascadable design, with simultaneous low input and output VSWR, and flat gain response. Performance results include measured and modeled data for a 2-7 GHz LNA with 2.5-dB noise figure, a 2-20-GHz distributed amplifier with 9.5-dB flat gain and 3.5-dB noise figure, and a 5-11-GHz and >3.5 balanced LNA with 10-dB gain and <2.5-dB noise figure (6-11 GHz). A preliminary temperature step-stress reliability evaluation on the discrete-process HEMT device is also presented.<<ETX>>

A 6-21-GHz monolithic HEMT 2*3 matrix distributed amplifier

The results of the first monolithic matrix distributed amplifier fabricated using pseudomorphic high-electron-mobility transistor (HEMT) technology are reported. The HEMT matrix amplifier obtains a combination of high gain, wide bandwidth, and reasonable IP3 and noise figure. The best gain response is 20 dB from 6 to 21 GHz. The noise figure is 5.5 dB and the third-order intercept point is 21 dBm. In comparison to GaAs HBT and MESFET technologies, the HEMT matrix distributed amplifier shows the best promise for wideband millimeter-wave applications. >

A monolithic DC temperature compensation bias scheme for multistage HEMT integrated circuits

This work benchmarks the first demonstration of a multistage monolithic HEMT IC design which incorporates a DC temperature compensated current-mirror bias scheme. This is believed to be the first demonstrated monolithic HEMT bias scheme of its kind. The active bias approach has been applied to a 2-18 GHz five-section low noise HEMT distributed amplifier which achieves a nominal gain of 12.5 dB and a noise figure <2.5 dB across a 2-18 GHz band, The regulated current-mirror scheme achieves better than 0.2% current regulation over a 0-125/spl deg/C temperature range, The RF gain response was also measured over the same temperature range and showed less than 0.75 dB gain degradation. This results in a -0.006 dB//spl deg/C temperature coefficient which is strictly due to HEMT device G/sub m/ variation with temperature. The regulated current-mirror circuit can be employed as a stand-alone V/sub gs/-voltage reference circuit which fan be monolithically applied to the gate bias terminal of existing HEMT ICs for providing temperature compensated performance, This monolithic bias approach provides a practical solution to DC bias regulation and temperature compensation for HEMT MMICs which can improve the performance, reliability, and cost of integrated microwave assemblies (IMAs) used in space-flight military applications.

Monolithic V-band frequency converter chip set development using 0.2 /spl mu/m AlGaAs/InGaAs/GaAs pseudomorphic HEMT technology

Monolithic approaches of the development to V-band frequency converters have the advantages of lighter weight and lower cost over conventional hybrid approaches for high volume insertions into satellite communication systems. This paper presents the design, fabrication, and performance of a monolithic V-band frequency converter chip set using 0.2 /spl mu/m AlGaAs/InGaAs/GaAs pseudomorphic HEMT technology. This chip set consists of three monolithic macrocells and a microcell: an upconverter, a downconverter, and a frequency multiplier for LO signal. A monolithic balanced amplifier microcell is also used to form the LO chain. Individual components, including amplifiers, mixer, and frequency doublers are also described. The superb measured results obtained from this chip set show great promise of the MMIC insertions for the system applications, and represent state-of-the-art performance of MMIC at this frequency. >

Cryogenic characteristics of wide-band pseudomorphic HEMT MMIC low-noise amplifiers

Two wideband (8-18-GHz) single-stage MMIC (monolithic microwave integrated circuit) low-noise amplifiers (LNAs) using 0.2- mu m T-gate InGaAs pseudomorphic HEMT (high-electron-mobility transistor) technology, designed and fabricated for room temperature operation, were evaluated and compared at cryogenic temperatures below 20 K. One is a balanced design using 3-dB Lange couplers, and the other is a feedback design using a series RLC parallel feedback network. The gain flatness over the 8-18-GHz frequency band was maintained for both amplifiers at room and cyrogenic temperatures, indicating that the topology for wideband designs is insensitive to temperature of operation. As the physical temperature decreased from 297 K to below 20 K, the balanced LNA exhibited an average gain increase of 2 dB and as much as an eightfold reduction of noise temperature to 20 K, while the feedback LNA exhibited an average gain increase of less than 1 dB and an average foufold reduction of noise temperature to 50 K. The negative feedback network of the feedback LNA resulted in less gain increase and less noise temperature reduction at cryogenic temperatures. >

Monolithic regulated self-biased HEMT MMIC's

This work benchmarks the first demonstration of a monolithic HEMT IC design which incorporates active regulated self-bias. The HEMT current regulator design consists of integrating an op-amp in a feedback configuration with the LNA to achieve gain, noise figure, and DC bias performance which is tolerant to threshold variations due to the HEMT process. The HEMT LNA bias current can be maintained to within /spl plusmn/3% variation over a process threshold variation (V,,) of /spl plusmn/0.5 V. The bias circuitry regulates the bias current to within 1.5% over a 100/spl deg/C temperature range. The amplifier has a nominal gain of 10 dB and a noise figure of 2.5 dB over a 1-10 GHz bandwidth. Across several wafers with a threshold voltage spread of 0.5 V, the regulated LNA maintains repeatable gain and noise figure which varies by less than 1 and 0.75 dB, respectively. The monolithic regulated self-bias technique can be integrated with other HEMT MMICs in order to improve the performance and reliability, as well as to reduce the cost and weight of Integrated Microwave Assemblies (IMAs). >

A cryogenically-cooled wide-band HEMT MMIC low-noise amplifier

A balanced single-stage wideband HEMT MMIC low-noise amplifier (LNA) was designed, fabricated, cooled to a temperature of 19 K, and evaluated from 8-18 GHz. The MMIC LNA performed without damage at all test temperatures. The amplifier gain flatness over the 8-18-GHz frequency band was maintained at both room and cryogenic temperature, indicating that the broadband design topology is relatively insensitive to operation temperature. Gain increased an average of 2 dB, while the noise temperature exhibited as much as an eightfold reduction from 160 K to 20 K at 19 K operation temperature. This is the first result on performance of a cryogenically cooled HEMT MMIC LNA. >

A monolithic HEMT regulated self-biased LNA

This work benchmarks the first demonstration of a monolithic HEMT LNA design which incorporates active regulated self-bias. The HEMT LNA bias current can be maintained to within /spl plusmn/3% variation over a process threshold variation (Vgs) of /spl plusmn/0.5 Volt. The bias circuitry regulates the bias current to within 1.5% over a 100/spl deg/C temperature range. The amplifier has a nominal gain of 10 dB and a noise figure of 2.5 dB over a 1-10 GHz bandwidth. Across several wafers with a threshold voltage spread of 0.5 Volts, the active bias-regulated LNA maintains repeatable gain and noise figure which varies by less than 1 dB and 0.75 dB respectively. This monolithic regulated self-biased LNA demonstration sheds new light on the producibility and reliability of HEMT MMICs and their applications.<<ETX>>

A 9-16 GHz monolithic HEMT low noise amplifier with embedded limiters

A novel 9-16 GHz monolithic HEMT low noise amplifier with on-chip limiters has been designed, fabricated, and measured. This paper presents the design topology, the new fabrication technology, and the on-wafer measurements of this circuit. The limiter consists of one PIN diode and one Schottky diode. The low noise amplifier itself is a single stage balanced amplifier with one limiter embedded in each single-ended amplifier.<<ETX>>A novel 9-16 GHz monolithic HEMT low noise amplifier with on-chip limiters has been designed, fabricated, and measured. This paper presents the design topology, the new fabrication technology, and the on-wafer measurements of this circuit. The limiter consists of one PIN diode and one Schottky diode. The low noise amplifier itself is a single stage balanced amplifier with one limiter embedded in each single-ended amplifier.<<ETX>>

A K-band HEMT low noise receive MMIC for phased array applications

A state-of-the-art InGaAs HEMT (high electron mobility transistor) receive MMIC (microwave monolithic integrated circuit) consisting of a low-noise amplifier and a novel 3-bit phase shifter has been fabricated and evaluated for receive phased-array development at 20 GHz. The low-noise amplifier employs series and shunt feedback to provide high gain and low noise performance while the 3-bit phase shifter utilizes a novel switched-allpass approach to minimize circuit size. The monolithic receive chip has demonstrated noise figures of less than 2.75 dB and gains between 11.8 and 14.1 dB for the 8 phase-shift states across the 20.2-21.2 GHz frequency range.<<ETX>>