By Topic

Terahertz Science and Technology, IEEE Transactions on

Issue 1 • Date Jan. 2014

Filter Results

Displaying Results 1 - 25 of 25
  • Table of contents

    Page(s): C1 - C4
    Save to Project icon | Request Permissions | PDF file iconPDF (164 KB)  
    Freely Available from IEEE
  • IEEE Transactions on Terahertz Science and Technology publication information

    Page(s): C2
    Save to Project icon | Request Permissions | PDF file iconPDF (145 KB)  
    Freely Available from IEEE
  • Editorial

    Page(s): 1 - 4
    Save to Project icon | Request Permissions | PDF file iconPDF (1489 KB)  
    Freely Available from IEEE
  • Terahertz Pioneers: A Series of Interviews with Significant Contributors to Terahertz Science and Technology

    Page(s): 5
    Save to Project icon | Request Permissions | PDF file iconPDF (107 KB)  
    Freely Available from IEEE
  • Terahertz Pioneer: Shenggang Liu “China's Father of Vacuum and Microwave Electronics”

    Page(s): 6 - 11
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (228 KB) |  | HTML iconHTML  

    Presents an interview with Shenggang Liu, a pioneer in terahertz science. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Field Exposure and Dosimetry in the THz Frequency Range

    Page(s): 12 - 25
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2431 KB) |  | HTML iconHTML  

    With a growing number of applications utilizing THz radiation appearing on the market the question of health protection against non-ionizing electromagnetic fields arises in this frequency range, as at lower frequencies before. To date, about 50 independent empirical studies on living organisms, model systems and cells have been performed to clarify bio-electromagnetic interaction in the THz frequency range. Many of these studies find behavioral effects or effects on the cellular level, even at non-thermal exposure levels, while others do not report effects other than thermally induced damage. We discuss the general challenges in performing reliable field exposure experiments in the THz frequency range and describe a methodology that was adopted in a large campaign searching for genotoxic effects of THz radiation in vitro. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Demonstration of The Leaky Lens Antenna at Submillimeter Wavelengths

    Page(s): 26 - 32
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1711 KB) |  | HTML iconHTML  

    This paper presents the first demonstration of the applicability of the leaky lens antenna concept at THz frequencies. The antenna is integrated with a Kinetic Inductance Detector, so that the two of them function as an ultra sensitive detector over a bandwidth ranging from 0.15 to 1.5 THz. The system has been manufactured and characterized in terms radiation pattern properties and frequency response. We find that the measurements agree very well with the calculations. This demonstrates the manufacturability of the Leaky Lens for use at THz frequency, opening the possibilities for novel broad-band detection concepts. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Measurement of Silicon Micromachined Waveguide Components at 500–750 GHz

    Page(s): 33 - 38
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1112 KB) |  | HTML iconHTML  

    This paper presents techniques used to assemble and measure micromachined submillimeter-wave waveguide circuits operating from 500 to 750 GHz. A novel micromechanical compression pin is developed to improve wafer-to-wafer alignment to less than 1 μm. Connection between the silicon waveguide and the VNA is aligned through a silicon boss that inserts into the custom waveguide flange. Waveguide loss is characterized for both E- and H-plane split waveguides and is found to be similar to standard metal waveguides. Finally, measurement of a 3 dB hybrid coupler operating from 500 to 600 GHz is presented. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Repeatability and Mismatch of Waveguide Flanges in the 500–750 GHz Band

    Page(s): 39 - 48
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2398 KB) |  | HTML iconHTML  

    This paper presents a study characterizing the connection repeatability and reflection coefficient of submillimeter waveguide flanges in the 500-750 GHz band (WR-1.5 or WM-380). The connection repeatability of four types of flange was measured using one-port measurements and a “load-reference” technique with a vertically mounted system to mitigate gravitational bias. To measure the error-corrected complex reflection coefficients of pairs of waveguide flanges, a calibration procedure insensitive to flange misalignment was used. This SDD(RO) calibration method employs four standards: a flush short, two delay shorts with different but unspecified offsets, and a radiating open-ended waveguide. The uncertainty associated with this calibration method is investigated and it is used to estimate the reflection coefficient resulting from flange misalignment. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Broadband, Micromachined Rectangular Waveguide to Cavity-Backed Coplanar Waveguide Transition Using Impedance-Taper Technique

    Page(s): 49 - 55
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1211 KB) |  | HTML iconHTML  

    This paper presents a broadband fully micromachined transition from rectangular waveguide to cavity-backed CPW line for submillimeter-wave (sub-MMW) and terahertz applications. A cavity-backed CPW line (CBCBW) is a planar transmission line that is designed and optimized for minimum loss while providing 50- Ω characteristic impedance. This line is shown to provide less than 0.12 dB/mm loss over the entire J-band (220-325 GHz). The transition from CBCPW to waveguide is realized in three steps to achieve a broadband response with a topology amenable to silicon micromachining. The first step is a tapered transition from the CBCPW line to a 50- Ω reduced-height waveguide. The next two steps utilize a novel in-plane impedance tapering technique to transition from the reduced-height waveguide to the on-wafer regular height waveguide. The full transition has less than 0.9 dB of insertion loss and more than 13 dB of return loss over the entire J-band (39% bandwidth). Silicon micromachining technology is used to fabricate prototypes of back-to-back CBCPW line-to-waveguide transitions. A novel waveguide-probe measurement setup is introduced and utilized to evaluate the performance of the transitions and the CBCPW lines. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Design and Characterization of H -Band (220–325 ~ GHz) Amplifiers in a 250-nm InP DHBT Technology

    Page(s): 56 - 64
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1443 KB) |  | HTML iconHTML  

    Design and characterization of InP DHBT amplifiers in common-emitter and common-base topologies are presented. Both one-stage and multistage circuits are demonstrated. For one of the amplifiers, a peak gain of 24 dB at 255 GHz is measured, which is among the highest reported gains for HBT amplifiers above 200 GHz, and more than 10 dB gain at 210-315 GHz. The noise figure of this amplifier is measured on-wafer at 240-295 GHz, and it demonstrates a minimum noise figure of 10.4 dB at 265 GHz, which is the lowest reported noise figure for HBT amplifiers above 200 GHz. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Non-Imaging Winston Cone Concentrators for Submillimeter-Wave, Overmoded Waveguide

    Page(s): 65 - 74
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1835 KB) |  | HTML iconHTML  

    We describe the design, simulation, and measured performance of concentrators designed to couple submillimeter wavelength radiation from free space into highly overmoded, rectangular, WR-10 waveguide. They consist of a combination of a Winston cone (also called a compound parabolic concentrator or CPC) with an adiabatic circular to rectangular transition. They are intended for use as adapters, between instruments using overmoded WR-10 waveguide as input or output and sources propagating through free space. Unlike conventional waveguide-coupled antennas, a geometric optics analysis is more appropriate than a mode-by-mode electromagnetic calculation of impedance and far-field pattern. Six separate designs were studied, with input diameters from 5 to 16 mm, and “throat” diameters (i.e., diameters at the circular interface between cone and transition sections) of 1 to 4 mm. Measurements at 394 μm wavelength (760 GHz) using a far-IR waveguide laser beam indicate efficiencies of 40%-55%. The angular response is primarily determined by the Winston cone, and is well predicted by geometric optics theory, i.e., approximately constant out to an angle determined by the ratio of input to throat diameters. The efficiencies are primarily determined by the transition section, and for all concentrators are consistent with an average reflectance of 94% from the gold-plated, electroformed, interior surfaces. For each individual concentrator, efficiency variations with polarization, angular orientation and beamsize are below the measurement uncertainty. View full abstract»

    Open Access
  • 0.34-THz Wireless Link Based on High-Order Modulation for Future Wireless Local Area Network Applications

    Page(s): 75 - 85
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2740 KB) |  | HTML iconHTML  

    This paper presents a 0.34-THz wireless link for future wireless local area networks (WLANs), which is based on high order 16-quadrature amplitude modulation (16QAM). The system adopts super heterodyne transceivers and parallel digital signal-processing techniques. The 0.34-THz transceiver consists of a 0.34-THz subharmonic mixer, a 0.34-THz waveguide H-ladder bandpass filter, and a 0.17-THz multiplier chain. Two 0.34-THz Cassegrain antennas with 48.4-dBi gain have been developed to extend the transmission distance. Based on a 32-way parallel signal processing, we have successfully realized the 3-Gb/s, 16QAM real-time modulator and demodulator. The measured data indicate that the lowest bit error rate of the 0.34-THz, 3-Gb/s data link is 1.784×10-10 over a 50.0-m line-of-sight channel. The maximum received energy per bit to noise power spectral density ratio ( Eb/N0) is 23.8 dB, while the output power of transmitter is -17.5 dBm and the noise temperature of receiver is 5227 K. In addition, this paper presents a 0.34-THz WLAN prototype based on IEEE 802.11b/g protocol. The WLAN prototype, which consists of an access point and two terminal nodes, achieves a transmission data rate of 6.536 Mb/s over 1.15 m by using rectangular horn antennas. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Global Distribution of Water Vapor and Cloud Cover—Sites for High-Performance THz Applications

    Page(s): 86 - 100
    Multimedia
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3472 KB) |  | HTML iconHTML  

    Absorption of terahertz radiation by atmospheric water vapor is a serious impediment for radio astronomy and for long-distance communications. Transmission in the THz regime is dependent almost exclusively on atmospheric precipitable water vapor (PWV). Though much of the Earth has PWV that is too high for good transmission above 200 GHz, there are a number of dry sites with very low attenuation. We performed a global analysis of PWV with high-resolution measurements from the Moderate Resolution Imaging Spectrometer (MODIS) on two NASA Earth Observing System (EOS) satellites over the year of 2011. We determined PWV and cloud cover distributions and then developed a model to find transmission and atmospheric radiance as well as necessary integration times in the various windows. We produced global maps over the common THz windows for astronomical and satellite communications scenarios. Notably, we show that, up through 1 THz, systems could be built in excellent sites of Chile, Greenland, and the Tibetan Plateau, while Antarctic performance is good to 1.6 THz. For a ground-to-space communication link up through 847 GHz, we found several sites in the Continental United States where mean atmospheric attenuation is less than 40 dB, which is not an insurmountable challenge for a link. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Global Modeling of Active Terahertz Plasmonic Devices

    Page(s): 101 - 109
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1563 KB) |  | HTML iconHTML  

    In this study, a full wave numerical technique is employed to characterize the propagation properties of 2-D plasmons along two-dimensional electron gas (2DEG) layers of biased hetero-structures at terahertz frequencies. This method is based on a coupled solution of Maxwell and hydrodynamic transport equations. In this manner, a complete description of carrier-wave interactions inside the 2DEG layer is obtained. Particularly, this simulator is employed to investigate the 2-D plasmon variations initiated by the application of an external bias along the hetero-structure. Substantial changes in the plasmon characteristics such as wavelength and decay length are reported. It is also revealed that two symmetrical plasmonic modes along the unbiased 2DEG layer split into new asymmetrical ones after applying the bias voltage. The simulation has been performed in different structures to examine the effects of various electron densities and the presence of periodic metallic gratings on the plasmon properties. Moreover, the 2-D plasmon reflections from boundaries terminated by ohmic contacts are separately studied. This research demonstrates the potentials of the 2-D conductors in the design of novel active terahertz plasmonic devices as modulators and amplifiers while proposing a new approach for their modeling. The results of this simulation are verified independently with an analytical model. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • State-of-the-Art Database of Terahertz Spectroscopy Based on Modern Web Technology

    Page(s): 110 - 115
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1147 KB) |  | HTML iconHTML  

    We present a review of a pioneering database on terahertz spectroscopy established by the National Institute of Information and Communication Technology and RIKEN. The database is universally available on the World Wide Web via the Internet since 2008 and was recently restructured on the basis of contemporary HTML5 technology. Flexibility and convenience to browse spectroscopic data are much improved. In the database, no less than 1500 spectroscopic data have been consolidated and provided for various materials under different conditions. Furthermore, a data upload system from general users has been prepared to enrich the database further. View full abstract»

    Open Access
  • Sinusoidally Modulated Graphene Leaky-Wave Antenna for Electronic Beamscanning at THz

    Page(s): 116 - 122
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1386 KB) |  | HTML iconHTML  

    This paper proposes the concept, analysis and design of a sinusoidally modulated graphene leaky-wave antenna with beam scanning capabilities at a fixed frequency. The antenna operates at terahertz frequencies and is composed of a graphene sheet transferred onto a back-metallized substrate and a set of polysilicon DC gating pads located beneath it. In order to create a leaky-mode, the graphene surface reactance is sinusoidally modulated via graphene's field effect by applying adequate DC bias voltages to the different gating pads. The pointing angle and leakage rate can be dynamically controlled by adjusting the applied voltages, providing versatile beamscanning capabilities. The proposed concept and achieved performance, computed using realistic material parameters, are extremely promising for beamscanning at THz frequencies, and could pave the way to graphene-based reconfigurable transceivers and sensors. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Special Guest Editorial THz Communications Bands: Enabling Commercial Use of Spectrum Above 95 GHz in USA: Comments Sought by FCC

    Page(s): 123 - 124
    Save to Project icon | Request Permissions | PDF file iconPDF (1789 KB)  
    Freely Available from IEEE
  • Comments on “THz Time-Domain Sensing: The Antenna Dispersion Problem and a Possible Solution”

    Page(s): 125 - 126
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (312 KB) |  | HTML iconHTML  

    Comments about the paper "THz Time-Domain Sensing: The Antenna Dispersion Problem and a Possible Solution" are written in the present manuscript, where is highlighted some important issues with the antenna analysis in the mentioned paper. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Authors' Reply

    Page(s): 127 - 128
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (253 KB)  

    We thank the author of [1] for providing us the occasion to explain more in detail the procedure we have adopted in the numerical simulations presented in [2]. Specifically in [1], it is claimed that “it is not possible to calculate accurately the far field radiated by an antenna laying in an interface air-dielectric radiating in a semi-infinite substrate using CST software”. This is a statement which contradicts our experience since we have found in many works that MS CST1 provides accurate results for such configurations. In order to perform simulations of antennas at the interface between two dielectrics, the antenna (dipole or slot) should be placed between an air and a dielectric box which are closed in open boundaries to recreate infinite media. CST discredits the whole volume to compute the fields in this volume. The fields and impedance on either the dipole or slot are then well simulated. Some discrepancies could be found if the thickness of the air box is small in terms of the wavelength and the antenna radiates significant power into the air medium, which is not the case for the antennas studied in [2]. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • 39th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)

    Page(s): 129
    Save to Project icon | Request Permissions | PDF file iconPDF (1062 KB)  
    Freely Available from IEEE
  • 2014 IEEE Compound Semiconductor IC Symposium (CSICS)

    Page(s): 130
    Save to Project icon | Request Permissions | PDF file iconPDF (926 KB)  
    Freely Available from IEEE
  • Open Access

    Page(s): 131
    Save to Project icon | Request Permissions | PDF file iconPDF (1156 KB)  
    Freely Available from IEEE
  • IEEE Transactions on Terahertz Science and Technology Information for Authors

    Page(s): 132
    Save to Project icon | Request Permissions | PDF file iconPDF (109 KB)  
    Freely Available from IEEE
  • IEEE Transactions on Terahertz Science and Technology Editorial Board

    Page(s): C3
    Save to Project icon | Request Permissions | PDF file iconPDF (83 KB)  
    Freely Available from IEEE

Aims & Scope

IEEE Transactions on Terahertz Science and Technology is specifically aimed at the frequency range between 300 GHz and 10 THz – "Expanding the use of the Electromagnetic Spectrum.''

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Peter H. Siegel
California Institute of Technology
Jet Propulsion Laboratory