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

In this paper, background describing THz monolithic integrated circuits using InP HEMT is presented. This three-terminal transistor technology has been used to realize amplifiers, mixers, and multipliers operating at 670 GHz. Transistor and processing technology, packaging technology, and circuit results at 670 GHz are described. The paper concludes with initial results from a 670-GHz InP HEMT receiver and trends for InP HEMT components.

THz Monolithic Integrated Circuits Using InP High Electron Mobility Transistors

Single-layer, wideband, and low-loss corporate-feed networks for slot antenna arrays are described. The antenna is built using ridge gap waveguide technology, formed between two parallel metal plates without the requirements of electrical contact between these plates. The corporate-feed network is realized by a texture of pins and a guiding ridge in the bottom plate, and the radiating slots are placed in the smooth top plate. The paper describes two test antennas: a 4 $\,\times\,$ 1 linear slot array and a 2 $\,\times\,$ 2 planar slot array. Both have been fabricated and tested at Ku- band. The linear array shows more than 20% bandwidth and the 2 $\,\times\,$ 2 array shows a bandwidth of 21% for 10-dB return loss. There are good agreements between measured and simulated patterns for both antennas. Measured gain for the planar array is found to be at least 12.2 dBi over 12–15 GHz band.

/pdf/wide-band-slot-antenna-arrays-with-single-layer-corporate-405rdmmfz6.pdf

Wide-Band Slot Antenna Arrays With Single-Layer Corporate-Feed Network in Ridge Gap Waveguide Technology

An analytical model and supporting measured data are presented for a preamplified W-band radiometer with a zero-bias detector appropriate for commercial millimeter-wave imaging cameras. Basic radiometer parameters, including RF bandwidth, are computed directly from simple low-frequency measurements and compare well with those obtained from RF measurements. A detailed analytical model shows how radiometer performance depends on internal component parameters, such as low-noise amplifier gain, noise factor, reflection coefficient, detector responsivity, etc. The measurements suggest that performance is sufficient for operation without a Dicke switch or mechanical chopping. A measured noise equivalent temperature difference of 0.45 K was obtained, assuming a single sensor is scanned across a focal plane, forming 32 pixels with 3.125-ms integration time per pixel. This sensitivity is considered sufficient by commercial manufacturers to obtain quality images in low-contrast (e.g., indoor) environments.

Passive Millimeter-Wave Imaging Module With Preamplified Zero-Bias Detection

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

Design data in the form of dimension tables is presented for probe transitions for microstrip substrates with 4 dielectric constants (2.2, 6.0, 10.1, and 13) in two orientations relative to the waveguide (broadside and longitudinal). These dimensions have been optimized for full waveguide bandwidth with >20 dB return loss using an electromagnetic CAD procedure. The dimensions can be applied to any size waveguide with a 2:1 width/height aspect ratio. Experimental verification for two of the designs applied to a W-band waveguide is presented.

Yoke-Choy Leong

Papers

Full band waveguide-to-microstrip probe transitions