Terahertz (THz) technology is one of emerging technologies that will change our life. A lot of attractive applications in security, medicine, biology, astronomy, and non-destructive materials testing have been demonstrated already. However, the realization of THz emitters and receivers is a challenge because the frequencies are too high for conventional electronics and the photon energies are too small for classical optics. As a result, THz radiation is resistant to the techniques commonly employed in these well established neighbouring bands.

https://www.degruyter.com/document/doi/10.2478/s11772-011-0033-3/pdf

Terahertz detectors and focal plane arrays

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.

/pdf/an-overview-of-solid-state-integrated-circuit-amplifiers-in-375xqeot7y.pdf

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

New and emerging terahertz technology applications make this a very exciting time for the scientists, engineers, and technologists in the field. New sensors and detectors have been the primary driving force behind the unprecedented progress in terahertz technology, but in the last decade extraordinary developments in terahertz sources have also occurred. Driven primarily by space based missions for Earth, planetary, and astrophysical science, frequency multiplied sources have dominated the field in recent years, at least in the 2-3 THz frequency range. More recently, over the past few years terahertz quantum cascade lasers (QCLs) have made tremendous strides, finding increasing applications in terahertz systems. Vacuum electronic devices and photonic sources are not far behind either. In this article, the various technologies for terahertz sources are reviewed, and future trends are discussed.

Technology, Capabilities, and Performance of Low Power Terahertz Sources

We report the results of a high-performance all-solid-state broad-band frequency multiplier chain at 1500 GHz, which uses four cascaded planar Schottky-barrier varactor doublers. The multipliers are driven by monolithic-microwave integrated-circuit-based high electron-mobility transistor power amplifiers around 95 GHz with 100-150 mW of pump power. The design incorporates balanced doublers utilizing novel substrateless and membrane device fabrication technologies, achieving low-loss broad-band multipliers working in the terahertz range. For a drive power of approximately 100 mW in the 88-99-GHz range, the doublers achieved room-temperature peak efficiencies of approximately 30% at the 190-GHz stage, 20% at 375 GHz, 9% at 750 GHz, and 4% at the 1500-GHz stage. When the chain was cooled to 120 K, approximately 40 /spl mu/W of peak output power was measured for 100 mW of input pump power.

http://www.jsward.com/publications/2004-05-MTT-Chattopadhyay.pdf

An all-solid-state broad-band frequency multiplier chain at 1500 GHz

The state-of-the art of terahertz heterodyne receivers are reviewed. Emphasis is placed on front-end components such as mixers and local oscillators. The back-end technology is described to a lesser extent. Recent developments, which are expected to have a major impact in the future, are also discussed.

Terahertz Heterodyne Receivers

A set of W-band power amplifier (PA) modules using monolithic microwave integrated circuits (MMICs) have been developed for the local oscillators of the far-infrared and sub-millimeter telescope (FIRST). The MMIC PA chips include three driver and three PAs, designed using microstrip lines, and another two smaller driver amplifiers using coplanar waveguides, covering the entire W-band. The highest frequency PA, which covers 100-113 GHz, has a peak power of greater than 250 mW (25 dBm) at 105 GHz, which is the best output power performance for a monolithic amplifier above 100 GHz to date. These monolithic PA chips are fabricated using 0.1-/spl mu/m AlGaAs/InGaAs/GaAs pseudomorphic T-gate power high electron-mobility transistors on a 2-mil GaAs substrate. The module assembly and testing, together with the system applications, is also addressed in this paper.

/pdf/power-amplifier-modules-covering-70-113-ghz-using-mmics-3gznighmwe.pdf

Power-amplifier modules covering 70-113 GHz using MMICs

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.

/pdf/mmic-power-amplifiers-as-local-oscillator-drivers-for-first-21osbwm1yx.pdf

MMIC power amplifiers as local oscillator drivers for FIRST

This paper describes a set of power amplifier (PA) modules containing InP high electron mobility transistor (HEMT) monolithic millimeter-wave integrated circuit (MMIC) chips. The chips were designed and optimized for local oscillator sources in the 90-130 GHz band for the Atacama large millimeter array telescope. The modules feature 20-45 mW of output power, to date the highest power from solid state HEMT MMIC modules above 110 GHz.

Medium power amplifiers covering 90-130 GHz for the ALMA telescope local oscillators

A number of monolithic W-band power amplifiers have been developed for local oscillators of the Far Infrared and Sub-millimeter Telescope.

Monolithic Power Amplifiers Covering 70-115 GHz

This paper focuses on InP-based, HEMT Monolithic Millimeter-wave Integrated Circuit (MMIC) power amplifiers for applications to heterodyne receivers, transmitters, and commmunications circuits.

Alejandro Peralta

Papers

Power-amplifier modules covering 70-113 GHz using MMICs

MMIC power amplifiers as local oscillator drivers for FIRST

Medium power amplifiers covering 90-130 GHz for the ALMA telescope local oscillators

Monolithic Power Amplifiers Covering 70-115 GHz

Advanced HEMT MMIC circuits for millimeter and submillimeter-wave power sources