High Electron Mobility Transistor Amplifier Research Articles

Low-noise cryogenic microwave amplifier characterization with a calibrated noise source.

Parametric amplifiers have become a workhorse in superconducting quantum computing; however, research and development of these devices has been hampered by inconsistent and, sometimes, misleading noise performance characterization methodologies. The concepts behind noise characterization are deceptively simple, and there are many places where one can make mistakes, either in measurement or in interpretation and analysis. In this article, we cover the basics of noise performance characterization and the special problems it presents in parametric amplifiers with limited power handling capability. We illustrate the issues with three specific examples: a high-electron mobility transistor amplifier, a Josephson traveling-wave parametric amplifier, and a Josephson parametric amplifier. We emphasize the use of a 50-Ω shot noise tunnel junction (SNTJ) as a broadband noise source, demonstrating its utility for cryogenic amplifier amplifications. These practical examples highlight the role of loss as well as the additional parametric amplifier "idler" input mode.

Characterizing cryogenic amplifiers with a matched temperature-variable noise source.

We present a cryogenic microwave noise source with a characteristic impedance of 50 Ω, which can be installed in a coaxial line of a cryostat. The bath temperature of the noise source is continuously variable between 0.1 K and 5 K without causing significant back-action heating on the sample space. As a proof-of-concept experiment, we perform Y-factor measurements of an amplifier cascade that includes a traveling wave parametric amplifier and a commercial high electron mobility transistor amplifier. We observe system noise temperatures as low as 680-200 +20 mK at 5.7 GHz corresponding to 1.5-0.7 +0.1 excess photons. The system we present has immediate applications in the validation of solid-state qubit readout lines.

A GaN HEMT Amplifier Design for Phased Array Radars and 5G New Radios.

Power amplifiers applied in modern active electronically scanned array (AESA) radars and 5G radios should have similar features, especially in terms of phase distortion, which dramatically affects the spectral regrowth and, moreover, they are difficult to be compensated by predistortion algorithms. This paper presents a GaN-based power amplifier design with a reduced level of transmittance distortions, varying in time, without significantly worsening other key features such as output power, efficiency and gain. The test amplifier with GaN-on-Si high electron mobility transistors (HEMT) NPT2018 from MACOM provides more than 17 W of output power at the 62% PAE over a 1.0 GHz to 1.1 GHz frequency range. By applying a proposed design approach, it was possible to decrease phase changes on test pulses from 0.5° to 0.2° and amplitude variation from 0.8 dB to 0.2 dB during the pulse width of 40 µs and 40% duty cycle.

Lynx x-ray microcalorimeter.

Lynx is an x-ray telescope, one of four large satellite mission concepts currently being studied by NASA to be a flagship mission. One of Lynx’s three instruments is an imaging spectrometer called the Lynx x-ray microcalorimeter (LXM), an x-ray microcalorimeter behind an x-ray optic with an angular resolution of 0.5 arc sec and ∼2 m2 of area at 1 keV. The LXM will provide unparalleled diagnostics of distant extended structures and, in particular, will allow the detailed study of the role of cosmic feedback in the evolution of the Universe. We discuss the baseline design of LXM and some parallel approaches for some of the key technologies. The baseline sensor technology uses transition-edge sensors, but we also consider an alternative approach using metallic magnetic calorimeters. We discuss the requirements for the instrument, the pixel layout, and the baseline readout design, which uses microwave superconducting quantum interference devices and high-electron mobility transistor amplifiers and the cryogenic cooling requirements and strategy for meeting these requirements. For each of these technologies, we discuss the current technology readiness level and our strategy for advancing them to be ready for flight. We also describe the current system design, including the block diagram, and our estimate for the mass, power, and data rate of the instrument.

Integrated high electron mobility transistors in GaAs/AlGaAs heterostructures for amplification at sub-Kelvin temperatures

We demonstrate the use of custom high electron mobility transistors (HEMTs) fabricated in GaAs/AlGaAs heterostructures to amplify current from quantum dot devices. The amplifier circuit is located adjacent to the quantum dot device, at sub-Kelvin temperatures, in order to reduce the impact of cable capacitance and environmental noise. Using this circuit, we show a current gain of 380 for 0.56 μW of power dissipation, with a bandwidth of 2.7 MHz and current noise referred to the input of 24 fA/Hz1/2 for frequencies of 0.1–1 MHz. The power consumption required for similar gain is reduced by more than a factor of 20 compared to a previous demonstration using a commercial off-the-shelf HEMT. We also demonstrate integration of a HEMT amplifier circuit on-chip with a quantum dot device, which has the potential to reduce parasitics and should allow for more complex circuits with reduced footprints.

Low‐phase noise 8.22 GHz GaN HEMT oscillator using a feedback multi‐path transformer

AbstractThis article designs a low‐phase noise 8.22 GHz GaN high electron‐mobility transistor (HEMT) oscillator in the WIN 0.25 μm GaN HEMT process. The oscillator uses a HEMT amplifier with a transformer as the feedback network. The transformer uses a 3‐path secondary inductor and a single‐path primary inductor. The GaN oscillator consumes the power 4.328 mW and generates a signal at 8.22 GHz with an output power −11.35 dBm. At 1 MHz frequency offset from the carrier at 8.22 GHz the phase noise is −120.82 dBc/Hz, the figure of merit of the proposed oscillator is −192.76 dBc/Hz. The oscillator chip occupies an area of 2 × 1 mm2.

100-GHz Radio and Power Over Fiber Transmission Through Multicore Fiber Using Optical-to-Radio Converter

We designed and fabricated a 100-GHz range integrated photoreceiver with zero-bias operational uni-traveling-carrier photodiode and pseudomorphic high electron mobility transistor amplifier, which performed the roles of photonic power generation and 100-GHz RF signal generation. Using the integrated photoreceiver, high data rate radio- and power-over-fiber transmission through multicore fiber communication was demonstrated. Subsequently, a bit error rate of $1\times 10^{- 3}$ could be achieved with 12 Gb/s, orthogonal frequency division multiplexing, 16 quadrature amplitude modulation, and an intermediate frequency of 92 GHz. The crosstalk issue in radio- and power-over-fiber transmission through multicore fiber was discussed.

100-GHz Fiber-Fed Optical-to-Radio Converter for Radio- and Power-Over-Fiber Transmission

We have developed a 100-GHz fiber-fed optical-to-radio converter for radio- and power-over-fiber transmission. A zero-bias operational high-speed photodetector (3-dB bandwidth >100 GHz) could be applied for the optical-to-radio converter, taking significant advantage of no-bias feed 100-GHz operation. We have successfully demonstrated simultaneous radio and power generation from one device through a bias-T circuit. A 100-GHz pseudomorphic high electron mobility transistor amplifier allowed a hybrid integrated photoreceiver to enhance the O/E conversion gain. Using the generated electric power, a gate bias in the 100-GHz amplifier was driven. The performance of each device and the integrated photoreceiver is described. High data rate photonic wireless transmission based on photonic power supply without external electric power supply is demonstrated.

The SuperCDMS SNOLAB Detector Tower

The SuperCDMS collaboration is moving forward with the design and construction of SuperCDMS SNOLAB, where the initial deployment will include $$\sim $$ 30 kg of Ge and $$\sim $$ 5 kg of Si detectors. Here, we will discuss the associated cryogenic cold hardware required for the detector readout. The phonon signals will be read out with superconducting quantum interference device arrays and the ionization signals will use high electron mobility transistor amplifiers operating at 4 K. A number of design challenges exist regarding the required wiring complex impedance, noise pickup, vibration, and thermal isolation. Our progress to date will be presented.

Microcontact-Enhanced Thermoelectric Cooling of Ultrahigh Heat Flux Hotspots

The dissipated power of insulated gate bipolar transistor and high electron mobility transistor amplifiers is typically nonuniform, resulting in areas of elevated temperature, or hotspots, which can have very large heat fluxes, on the order of 1000 W/cm2. While various bulk cooling systems are being researched to remove large amounts of heat, they uniformly reduce the chip temperature, leaving the temperature nonuniformity. Therefore, advanced hotspot cooling techniques, which provide localized cooling, are also required to unlock the full potential of cutting edge power devices. Thermoelectric coolers have previously been demonstrated as an effective method of producing on-demand cooling for the removal of localized hotspots. However, the heat flux of the hotspots that can be cooled is limited by the maximum cooling flux of thermoelectric devices. This paper demonstrates the thermal and reliability performance of a microcontact-enhanced thermoelectric cooling configuration, which uses a contact structure etched directly out of the electronic substrate to concentrate the cooling produced by a commercially available thermoelectric module. The 22 K of cooling, resulting in a hotspot temperature rise of <6 K for a heat flux of 2.5 kW/cm2, was experimentally demonstrated using a Laird HV37 thin-film thermoelectric module with a maximum device level cooling flux of 66 W/cm2. A numerical model was created, and it is predicted that when the chip and microcontact geometry is optimized, hotspots with heat fluxes in excess of 3 kW/cm2 can be cooled by nearly 40 K, reducing the hotspot temperature rise to 0 K.

Z45: A new 45-GHz band dual-polarization HEMT receiver for the NRO 45-m radio telescope

Abstract We developed a dual-linear-polarization HEMT (High Electron Mobility Transistor) amplifier receiver system of the 45-GHz band (hereafter Z45), and installed it in the Nobeyama 45-m radio telescope. The receiver system is designed to conduct polarization observations by taking the cross-correlation of two linearly polarized components, from which we process full Stokes spectroscopy. We aim to measure the magnetic field strength through the Zeeman effect of the emission line of CCS (JN = 43–32) toward pre-protostellar cores. A linear-polarization receiver system has a smaller contribution of instrumental polarization components to the Stokes V spectra than that of the circular polarization system, so that it is easier to obtain the Stokes V spectra. The receiver has an RF frequency of 42–46 GHz and an intermediate frequency (IF) band of 4–8 GHz. The typical noise temperature is about 50 K, and the system noise temperature ranges from 100 to 150 K over the frequency of 42–46 GHz. The receiver system is connected to two spectrometers, SAM45 and PolariS. SAM45 is a highly flexible FX-type digital spectrometer with a finest frequency resolution of 3.81 kHz. PolariS is a newly developed digital spectrometer with a finest frequency resolution of 60 Hz, and which has a capability to process the full-Stokes spectroscopy. The half-power beam width (HPBW) was measured to be 37″ at 43 GHz. The main beam efficiency of the Gaussian main beam was derived to be 0.72 at 43 GHz. The SiO maser observations show that the beam pattern is reasonably round at about 10% of the peak intensity and the side-lobe level was less than 3% of the peak intensity. Finally, we present some examples of astronomical observations using Z45.

High fidelity readout of a transmon qubit using a superconducting low-inductance undulatory galvanometer microwave amplifier

We report high-fidelity, quantum non-demolition, single-shot readout of a superconducting transmon qubit using a dc-biased superconducting low-inductance undulatory galvanometer (SLUG) amplifier. The SLUG improves the system signal-to-noise ratio by in a window compared with a bare high electron mobility transistor amplifier. An optimal cavity drive pulse is chosen using a genetic search algorithm, leading to a maximum combined readout and preparation fidelity of with a measurement time of . Using post-selection to remove preparation errors caused by heating, we realize a combined preparation and readout fidelity of .

Microwave SQUID Multiplexer for the Readout of Metallic Magnetic Calorimeters

We have realized a frequency-domain multiplexing technique for the readout of large metallic magnetic calorimeter detector arrays. It is based on non-hysteretic single-junction SQUIDs and allows for a simultaneous readout of hundreds or thousands of detectors by using a single cryogenic high electron mobility transistor amplifier and two coaxial cables that are routed from room-temperature to the detector array. We discuss the working principle of the multiplexer and present details about our prototype multiplexer design. We show that fabricated devices are fully operational and that characteristic SQUID parameters such as the input sensitivity of the SQUID or the resonance frequency of the readout circuit can be predicted with confidence. Our best device so far has shown a magnetic flux white noise level of 1.4 m\({\Phi _0}/\sqrt{Hz}\) which can in future be reduced by an optimization of the fabrication processes as well as an improved microwave readout system.

Submicrosecond-timescale readout of carbon nanotube mechanical motion

We report fast readout of the motion of a carbon nanotube mechanical resonator. A close-proximity high electron mobility transistor amplifier is used to increase the bandwidth of the measurement of nanotube displacements from the kHz to the MHz regime. Using an electrical detection scheme with the nanotube acting as a mixer, we detect the amplitude of its mechanical motion at room temperature with an intermediate frequency of 6 MHz and a timeconstant of 780 ns, both up to five orders of magnitude faster than achieved before. The transient response of the mechanical motion indicates a ring-down time faster than our enhanced time resolution, placing an upper bound on the contribution of energy relaxation processes to the room temperature mechanical quality factor.

Compact Photonic Package for High-Power E-Band (60–90 GHz) Photoreceiver Modules

In this work, we present a novel photonic package for high-power photoreceiver modules operating within the E-band (60–90 GHz). The developed Kovar package features a compact size of only 6×3.5×2 cm3 and comprises an optical single-mode fiber (SMF) input, DC bias supply connections and a WR-12 output for coupling out of the radio frequency (RF) signal. As integration platform, a RF laminate submount with implemented planar bias-T based upon grounded coplanar waveguide (GCPW) transmission line circuitry is used for efficient mmW propagation, concluding in a GCPW-to-WR-12-transition. Finite element method (FEM) simulations have been carried out to analyze the frequency range of interest. Besides applied adhesive and wire bonding approaches for assembly inside the package, the RF submount exhibits sections for hybrid integration of single components, e.g. of a high-frequency waveguide photodiode. Optionally, up to two high-electron-mobility-transistor (HEMT) power amplifiers can be integrated within the GCPW circuitry. In addition, the RF laminate is mounted on a brass platform. For uniform thermal expansion within the module, a Peltier element is integrated. Concerning the saturation output power of given HEMT amplifiers, e.g. in the order of +17.5 dBm, corresponding power levels are achievable for packaged devices. For instance, an output RF power of only −19.5 dBm within the 71–76 GHz band is required from the photodiode in conjunction with two cascaded HEMT amplifiers, which results in a total gain of ~37 dB. A small series of the introduced device has been already fabricated. First experimental achievements with in-house fabricated modules will be presented.

Mesoscopic resistor as a self-calibrating quantum noise source

We present a method for the measurement of the noise of microwave amplifiers operating at the single photon level. It is based on the shot noise produced by a nanowire resistor in the hot electron regime. This noise source is simply controlled by a dc current and offers the advantage of being self-calibrating. After testing the noise source with a cryogenic high electron mobility transistor amplifier, we demonstrate its usefulness by calibrating a Josephson parametric amplifier operating near the quantum limit.

A G-band cryogenic MMIC heterodyne receiver module for astronomical applications

We report cryogenic noise temperature and gain measurements of a prototype heterodyne receiver module designed to operate in the atmospheric window centered on 150 GHz. The module utilizes monolithic microwave integrated circuit (MMIC) InP high electron mobility transistor (HEMT) amplifiers, a second harmonic mixer, and bandpass filters. Swept local oscillator (LO) measurements show an average gain of 22 dB and an average noise temperature of 87 K over a 40 GHz band from 140 to 180 GHz when the module is cooled to 22 K. A spot noise temperature of 58 K was measured at 166 GHz and is a record for cryogenic noise from HEMT amplifiers at this frequency. Intermediate frequency (IF) sweep measurements show a 20 GHz IF band with less than 94 K receiver noise temperature for a fixed LO of 83 GHz. The compact housing features a split-block design that facilitates quick assembly and a condensed arrangement of the MMIC components and bias circuitry. DC feedthroughs and nano-miniature connectors also contribute to the compact design, so that the dimensions of the moduleare approximately 2.5 cm per side.

QUIET Coherent Polarimeter Modules

The Q/U Imaging ExperimenT (QUIET) consists of a pair of radiometer arrays designed to measure the B-mode polarization of the Cosmic Microwave Background (CMB) at 44 GHz (Q-band) and 95 GHz (W-band) with 19 and 90 modules at each frequency. The architecture of both arrays is based on miniaturized coherent polarimeters using High Electron Mobility Transistor (HEMT) chips for amplification; QUIET is the largest coherent microwave array ever fielded. We describe the detector technology used in Phase I of QUIET and our efforts to improve both the W-band module design and the fundamental performance of the HEMT amplifiers. These technology developments have wide application in the field of radio astronomy.

A Ku band internally matched high power GaN HEMT amplifier with over 30% of PAE

We report a high power Ku band internally matched power amplifier (IMPA) with high power added efficiency (PAE) using 0.3 μm AlGaN/GaN high electron mobility transistors (HEMTs) on 6H-SiC substrate. The internal matching circuit is designed to achieve high power output for the developed devices with a gate width of 4 mm. To improve the bandwidth of the amplifier, a T type pre-matching network is used at the input and output circuits, respectively. After optimization by a three-dimensional electromagnetic (3D-EM) simulator, the amplifier demonstrates a maximum output power of 42.5 dBm (17.8 W), PAE of 30% to 36.4% and linear gain of 7 to 9.3 dB over 13.8–14.3 GHz under a 10% duty cycle pulse condition when operated at Vds = 30 V and Vgs = −4 V. At such a power level and PAE, the amplifier exhibits a power density of 4.45 W/mm.

An Overview of Solid-State Integrated Circuit Amplifiers in the Submillimeter-Wave and THz Regime

We present an overview of solid-state integrated circuit amplifiers approaching terahertz frequencies based on the latest device technologies which have emerged in the past several years. Highlights include the best reported data from heterojunction bipolar transistor (HBT) circuits, high electron mobility transistor (HEMT) circuits, and metamorphic HEMT (mHEMT) amplifier circuits. We discuss packaging techniques for the various technologies in waveguide modules and describe the best reported noise figures measured in these technologies. A consequence of THz transistors, namely ultra-low-noise at cryogenic temperatures, will be explored and results presented. We also present a short review of power amplifier technologies for the THz regime. Finally, we discuss emerging materials for THz amplifiers into the next decade.