BANDWIDTH, Q FACTOR, AND RESONANCE MODELS OF ANTENNAS

Optimization of the Bandwidth of Electrically Small Planar Antennas

The bandwidth limitations of resonant, electrically small antennas that fully occupy a spherical volume are well defined by the inverse of the Chu-limit or the lower bound on quality factor. Recently, Gustafsson et al developed lower bounds for the Q of antennas of arbitrary shape. We have previously described antenna designs fully occupying a spherical volume and a cylindrical volume that exhi...

factor influencing the adoption of internet banking

دوره مشترک کارشناسی ارشد بازاریابی و تجارت الکترونیک دانشگاه تربیت مدرس_ دانشگاه تکنولوژی lule? چکیده پایان نامه عوامل موثر بر پذیرش اینترنت بانک توسط مشتریان پیشرفت فناوری اطلاعات و ارتباطات و به طور خاص رشد اینترنت جهت تراکنش های معاملات بازرگانی، تاثیر بسیار عمیقی در صنعت بانکداری داشته است.این در حالی ست که نفوذ بانکداری اینترنتی در کشورهای در حال توسعه بسیار کندتر از نفوذ آن ...

Bandwidth Improvement of Reflectarray Antennas Using Closely Spaced Elements

A bandwidth improvement method in reflectarray antennas by using closely space elements, i.e., unit-cell sizes smaller than λ/2, has been investigated both numerically and experimentally in this paper. A new definition of phase error has been introduced to analyze the broadband mechanism of closely spaced phasing elements. Through full wave EM simulations, it is revealed that closely spaced ele...

The Foster Reactance Theorem for Antennas and Radiation Q

The calculation of antenna has been an interesting and a controversial topic for years. In this paper, we first give a rigorous study of antenna by introducing a complete description of the complex power balance relation for an antenna system. Using the complex Poynting theorem, we have shown that the antenna is essentially equivalent to a one port lossy network. The Foster reactance theorem is...

A Nonlinear Technique for Bandwidth Improvement in Narrowband Antennas