182 research outputs found

    Chapter UWB Cognitive Radios

    Get PDF
    Management & management technique

    Disc Jockey jako twórca zależny – problem miksowania utworów w świetle przepisów ustawy z dnia 4 lutego 1994 r. o prawie autorskim i prawach pokrewnych

    Get PDF
    One of the fundamental issues regulated by the act on copyright law is the content of the rights vested in the author and related to his or her creation. The stipulations of the copyright law protect the author against an infringement of a personal bond relating him or her to the creation (personal copyrights) and provide him or her with economic benefits provided by the creation being exploited in various realms (copyright property law). The present paper addresses the problem of a disc jockey’s public presentation of music compositions and the protection of personal copyright and property law of the author of presented music

    UWB Cognitive Radios

    Get PDF

    Optimisation of sample thickness for THz-TDS measurements

    Get PDF
    How thick should the sample be for a transmission THz-TDS measurement? Should the sample be as thick as possible? The answer is `no'. Although more thickness allows T-rays to interact more with bulk material, SNR rolls off with thickness due to signal attenuation. Then, should the sample be extremely thin? Again, the answer is `no'. A sample that is too thin renders itself nearly invisible to T-rays, in such a way that the system can hardly sense the difference between the sample and a free space path. So, where is the optimal boundary between `too thick' and `too thin'? The trade-off is analysed and revealed in this paper, where our approach is to find the optimal thickness that results in the minimal variance of measured optical constants.Comment: 13 pages, 11 figure

    Novel Ultra-Sensitive Detectors in the 10–50 μm Wavelength Range

    Get PDF
    We have developed novel single-photon detectors in the 10–50 μm wavelength region. The detectors are charge-sensitive infrared phototransistors (CSIPs) fabricated in GaAs/AlGaAs double quantum well (QW) structures, in which a photo-generated hole (+e) in the floating gate (upper QW) modulates the conductance of a capacitively-coupled channel located underneath (lower QW). The excellent noise equivalent power (NEP = 8.3 × 10−19 W/Hz1/2) and specific detectivity (D* = 8 × 1014 cm Hz1/2/W) are demonstrated for 15 micron detection up to 23 K, which are by a few orders of magnitude better than those of other state-of-the-art high-sensitivity detectors. The dynamic range exceeds 106 (∼aW to pW) by repeatedly resetting the accumulated holes in the upper QW. Simple device structure makes the detectors feasible for array fabrication: Furthermore, monolithic integration with reading circuits will be possible

    Highly-Sensitive Thin Film THz Detector Based on Edge Metal-Semiconductor-Metal Junction

    Get PDF
    Terahertz (THz) detectors have been extensively studied for various applications such as security, wireless communication, and medical imaging. In case of metal-insulator-metal (MIM) tunnel junction THz detector, a small junction area is desirable because the detector response time can be shortened by reducing it. An edge metal-semiconductor-metal (EMSM) junction has been developed with a small junction area controlled precisely by the thicknesses of metal and semiconductor films. The voltage response of the EMSM THz detector shows the clear dependence on the polarization angle of incident THz wave and the responsivity is found to be very high (similar to 2,169 V/W) at 0.4 THz without any antenna and signal amplifier. The EMSM junction structure can be a new and efficient way of fabricating the nonlinear device THz detector with high cut-off frequency relying on extremely small junction area

    Terahertz communications for 5G and beyond

    Get PDF
    A brief discussion about the exclusive properties and applications of terahertz technology is provided in this chapter. The frequency spectrum terahertz (THz) is also discussed. The applications of terahertz in the field of sensors and terahertz for communications are covered. State-of-the-art literature starting from the early to the latest research conducted is provided and analyzed in terms of the performance of terahertz systems. Terahertz, known as Tera waves or T-waves rather than submillimeter wave, has approximately a fraction of a wavelength less than 30 μm. T-wave is heavily used in sensing and imaging applications, and has no ionization hazards and is an excellent candidate frequency band to defeat the multipaths interference problems for pulse communications. The lower quantum energy of T-waves identifies its potential applications toward near-field imaging, telecommunications, spectroscopy, and sensing, including medical diagnoses and security screening. Identification of DNA signatures including complex real-time molecular dynamics through dielectric resonance is a good example of terahertz spectroscopy instruments nowadays. This concluding chapter will not only address the practical applications of terahertz communications, but also identify the research challenges that lie ahead in terms of terahertz antenna desig
    corecore