著者
M. Pirai H. R. Hassani
出版者
一般社団法人 電子情報通信学会
雑誌
IEICE Electronics Express (ISSN:13492543)
巻号頁・発行日
vol.6, no.21, pp.1528-1534, 2009 (Released:2009-11-10)
参考文献数
8
被引用文献数
2 5

In this paper a reduced size microstrip log periodic dipole antenna with top loading of elements is presented. In many situations, the lateral size of the LPDA antenna has to be reduced to fit the antenna into the installation space. In this work, top loaded element structure is adopted to reduce the size of the dipole elements. Each straight dipole element of the LPDA antenna is turned into a T-shaped element whose total length is equal to that of the original straight dipole element length, resulting in a dipole length that is half that of the original dipole element, i.e. lateral size of the LPDA has been reduced by more than half. This procedure can be repeated to reduce the dipole element length even further, by placing a double T-shaped element on top of each other, resulting in an overall length that is almost 46% of the original dipole element length. Comparison of the reduced sized LPDA with that of the original LPDA shows that the VSWR (≤ 2.0) results of the reduced size LPDA are lower than those of the straight elements over the 2.3-8GHz frequency band. For the three LPDA structures results of peak gain shows that on average over the frequency band, 2-8GHz, gain varies between 5-6dBi. Simulation and measured results on VSWR, radiation pattern and gain at the various frequencies are provided.
著者
大賀 寿郎
出版者
一般社団法人 電子情報通信学会
雑誌
電子情報通信学会 基礎・境界ソサイエティ Fundamentals Review (ISSN:18820875)
巻号頁・発行日
vol.1, no.4, pp.4_46-4_61, 2008-04-01 (Released:2011-03-01)
参考文献数
30
被引用文献数
2 2

圧電材料を用いたマイクロホン,スピーカなどの音響部品は構造が簡単なことを特徴とし,長い歴史をもっており,最近の技術の進展にも見るべきものがある.しかし,この種の部品のまとまった技術解説が意外に少ない.ここでは基本的な事項の説明と実用部品の技術の概観を目的として,やや長く詳しい解説を行う.対象としてセラミック圧電材料と高分子圧電材料とを取り上げ,材料の性質,基本的な設計法から最新の研究成果までを述べる.
著者
Babak Mohammadian Abdolreza Nabavi
出版者
一般社団法人 電子情報通信学会
雑誌
IEICE Electronics Express (ISSN:13492543)
巻号頁・発行日
vol.7, no.19, pp.1453-1460, 2010 (Released:2010-10-10)
参考文献数
9
被引用文献数
1 1

A new wideband Orthogonal Frequency Division Multiplexing (OFDM) receiver based on split spectrum processing (SSP) technique is presented. In this receiver, the spectrum of the input signal is first decomposed into a number of sub-bands, and then independently down-converted to baseband for filtering and demodulation. This technique, which is characterized by the number of sub-bands and their bandwidths, reduces the sampling rate of analog-to-digital converter (ADC) by the sub-band bandwidth compared to conventional OFDM system. Analysis and simulation of the phase noise show that the new receiver exhibits the same bit error rate (BER) performance as the conventional OFDM system. Also, the Chebyshev II filter gives rise to superior BER performance compared to Butterworth, Chebyshev I, Elliptic, and Bessel filters. Interestingly, the traditional time domain synchronization algorithms can be employed for the new SSP receiver with only minor modifications.