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Author: search.filters.author.Supanakoon, PichayaSubject: search.filters.subject.Friis' transmission formula

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    Waveform distortion and transmission gain on ultra wideband impulse radio
    (2010-01-01)
    Promwong, Sathaporn
    ;
    Supanakoon, Pichaya
    ;
    Takada, Jun Ichi
    A waveform of an ultra wideband impulse radio (UWBIR) system can be extremely distorted through a channel even for free-space transmission because of antenna dispersion. This highly degrades the link budget performance. Therefore, the understand of antenna characteristics, which effects on waveform distortion, is necessary. This paper studies the waveform distortion due to antenna in free space transmission in UWB-IR system. The link budget is usually evaluated by using the Friis' transmission formula. However, it is not directly applicable to the UWB-IR transmission system. The link budget evaluation formula attended from conventional Friis' transmission formula that takes into account the transmitted waveform, its distortion due to the antennas, the channel and the correlation receiver is proposed. Since the antenna is significant pulse-shaping filters in UWB-IR system, the example kind of the log-periodic dipole antenna (LPDA) is experimentally examined, especially focused on the effect of the template waveforms. Copyright © 2010 The Institute of Electronics, Information and Communication Engineers.
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    Indoor propagation channel measurement of ultra wideband antenna with robotic
    (2005-12-01)
    Boonvisat, Satean
    ;
    Promwong, Sathapom
    ;
    Supanakoon, Pichaya
    ;
    Kaewmechai, Sompoph
    ;
    Sitiyopasakul, Pisan
    In this paper, the characterization of ultra wideband (UWB) antenna with robotic is evaluated. The measurement system consists of transmitter (Tx) and receiver (Rx) biconical antennas measured by using a vector network analyzer (VNA). To obtaining the data, measurements were performed at 3 GHz to 11 GHz covered by a VNA, which provided information on the amplitude and phase of the transmission coefficient. Friis' transmission formula is not directly applicable and the waveform distortion may degrade the transmission performance as well. The matched filter is considered at the receiver side to maximize the SNR for evaluation. The power delay profile and the UWB transmission gain, based on the extension of Friis' transmission formula take into account the transmitted waveform and the matched filter into the system for the free space of UWB. The experimental examples using the biconical antenna as the receiver install with robotic are presented in this paper. © 2005 IEEE.