Broadband sub-millimeter wave technology has received significant attention for potential applications in security, medical, and military imaging. Despite theoretical advantages of reduced size, weight, and power compared to current millimeter wave systems, sub-millimeter wave systems have been hampered by a fundamental lack of amplification with sufficient gain and noise figure properties. We report a broadband pixel operating from 300 to 340 GHz, biased off a single 2 V power supply. Over this frequency range, the amplifiers provide > 40 dB gain and <8 dB noise figure, representing the current state-of-art performance capabilities. This pixel is enabled by revolutionary enhancements to indium phosphide (InP) high electron mobility transistor technology, based on a sub-50 nm gate and indium arsenide composite channel with a projected maximum oscillation frequency fmax>1.0 THz. The first sub-millimeter wave-based images using active amplification are demonstrated as part of the Joint Improvised Explosive Device Defeat Organization Longe Range Personnel Imager Program. This development and demonstration may bring to life future sub-millimeter-wave and THz applications such as solutions to brownout problems, ultra-high bandwidth satellite communication cross-links, and future planetary exploration missions.
Broadband sub-millimeter wave technology has received significant attention for potential applications in security,
medical, and military imaging. Despite theoretical advantages of reduced size, weight, and power compared to current
millimeter-wave systems, sub-millimeter-wave systems are hampered by a fundamental lack of amplification with
sufficient gain and noise figure properties. We report on the development of a sub-millimeter wave amplifier module as
part of a broadband pixel operating from 300-350 GHz, biased off of a single 2V power supply. Over this frequency
range, > 38 dB gain and < 8.3 dB noise figure are obtained and represent the current state-of-art performance
capabilities. The prototype pixel chain consists of two WR3 waveguide amplifier blocks, and a horn antenna and diode
detector. The low noise amplifier Sub-Millimeter-wave Monolithic Integrated Circuit (SMMIC) was originally
developed under the DARPA SWIFT and THz Electronics programs and is based on sub 50 nm Indium Arsenide
Composite Channel (IACC) transistor technology with a projected maximum oscillation frequency fmax > 1.0 THz. This
development and demonstration may bring to life future sub-millimeter-wave and THz applications such as solutions to
brown-out problems, ultra-high bandwidth satellite communication cross-links, and future planetary exploration
The Heterodyne Instrument for Far Infrared (HIFI) on ESA's Herschel Space Observatory is comprised of five SIS receiver channels covering 480-1250 GHz and two HEB receiver channels covering 1410-1910 GHz. Two fixed tuned local oscillator sub-bands are derived from a common synthesizer to provide the front-end frequency coverage for each channel. The local oscillator unti will be passively cooled while the focal plane unit is cooled by superfluid helium and cold helium vapors. HIFI employs W-band GaAs amplifiers, InP HEMT low noise IF amplifiers, fixed tuned broadband planar diode multipliers, and novel material systems in the SIS mixtures. The National Aeronautics and Space Administration's Jet Propulsion Laboratory is managing the development of the highest frequency (1119-1250 GHz) SIS mixers, the highest frequency (1650-1910 GHz) HEB mixers, local oscillators for the three highest frequency receivers as well as W-band power amplifiers, varactor diode devices for all high frequency multipliers and InP HEMT components for all the receiver channels intermediate frequency amplifiers. The NASA developed components represent a significant advancement in the available performance. The current state of the art for each of these devices is presented along with a programmatic view of the development effort.
This paper describes the design and development of a state-of-the-art dual-channel 183 GHz InP based Monolithic Microwave Integrated Circuit (MMIC) radiometer. This is the world's first reported monolithic radiometer that operates at 183 GHz enabling high precision micro-miniature sensing of atmospheric chemistry components in this band. The radiometer features the following key components: a plug-in front end low noise amplifier module utilizing a broadband InP MMIC that sets the system noise figure, a low loss waveguide diplexer module, waveguide-to-microstrip transitions fabricated on Z-cut quartz, a mechanical design that can be easily modified to be hermetic, dual-channel output allowing double sideband detection, and a combination of HEMT and HBT InP and GaAs MMIC active components.
The Heterodyne Instrument for the Far-Infrared and Sub- millimeter Telescope requires local oscillators well into the terahertz frequency range. The mechanism to realize the local oscillators will involve synthesizers, active multiplier chains (AMC's) with output frequencies from 71 - 112.5 GHz, power amplifiers to amplify the AMC signals, and chains of Schottky diode multipliers to achieve terahertz frequencies. We will present the latest state-of-the-art results on 70 - 115 GHz Monolithic Millimeter-wave Integrated Circuit power amplifier technology.
TRW has recently developed InP low noise amplifiers operating at 140 GHz. Similar to the evolution of 94 GHz GaAs technology, this lays the foundation for the development of a 140 GHz MMIC receiver for use in a next generation passive millimeter-wave video camera capable of generating a real time display of the imaged scene. The advantages of going to 140 GHz, and the use of InP technology, will be discussed.
We report on the performance of power amplifiers as local oscillator drivers for millimeter and submillimeter-wave receivers. A MMIC power amplifier based on 0.1 micron GaAs HEMT technology on 50 micron thick substrate has been packaged in a waveguide block and characterized. Output power in excess of 100 mW is demonstrated over 88 - 94 GHz with more power easily achievable. The noise properties of the MMIC amplifier in multiplied local oscillator chains are characterized in a low noise superconductor-insulator-superconductor mixer based heterodyne receiver. A 386 GHz SIS mixer was used to characterize noise temperature in a laboratory environment. A more sensitive measurement of noise contribution from the amplifier was performed on a 278 GHz mixer/receiver at the Caltech Submillimeter-Wave Observatory, during astronomical observations. It is concluded that the MMIC amplifier does not add additional significant noise to the radiometer system.
We report an RF optical InP-based PIN-HEMT photoreceiver operating across a measured 36-46 GHz frequency band fabricated on the same wafer using selective area regrowth with molecular beam epitaxy. The photoreceiver design consists of a 20 micron circular InGaAs/InP photodiode integrated with a wide band 0.15 micron gate length InGaAs/InAlAs/InP low noise amplifier optimized for 44 GHz operation. The heterodyne technique of beating the frequency of two lasers was used to generate an RF modulated light signal at 1.3 micron wavelength. The output of the photoreceiver was measured on a spectrum analyzer and was found to be -24 to -27 dBm across a 36-46 GHz band.
We have developed an ultra-low noise 94 GHz MMIC amplifier using InGaAs/InAlAs/InP transistor technology. The MMIC designs incorporate a single transistor stage with input and output matching networks as well as gate and drain bias networks. Two MMICs have been incorporated into a single housing providing 10 dB of gain. At room temperature, the integrated amplifier has a measured noise of 365 K at 94 GHz. Cryogenic measurements have been performed using a direct detection total power radiometer with all amplification provided by MMIC amplifiers. The noise figure for the entire radiometer has been measured to be 78 K. The noise figure for the cryogenic InP MMIC 2-stage amplifier unit has been measured to be 51 K with a low power consumption of 0.84 mW per stage. The stability of the radiometer with a 4 GHz bandwidth, is characterized by a power spectrum with a '1/f knee' frequency of 45 Hz.
Recent improvements in material structure, device layout, fabrication process, and device matching have resulted in simultaneous improvements in power output, power gain, and power-added efficiency from large size GaAs-based pseudomorphic AlGaAs/hiGaAs HEMTs at millimeter-wave frequencies. Consequently efficient watt level building blocks are now available to build solid state power amplifiers capable of 1 to 20 watt power output for next generation military and civilian systems. This paper describes a state-of-the-art 0.15 pm power HEMT technology suitable for applications in this frequency range. Examples of MIC and MMIC power amplifier circuits are given to illustrate the achievable power performance. Preliminary study of the power HEMT reliability is also discussed.