Design concept of antennas for small mobile terminals and the future perspective

Rapid Prototyping across the Spectrum: RF to Optical 3D Electromagnetic Structures

“…The next category in the context of RF devices is printed 3D components. Antennas have remained the center of research as capacity needs increase with multimedia data and size constraints are tightened [75], especially in applications such as satellites [76] and mobile devices where size and weight are critical [77]. 3D antennas provide design flexibility needed in such systems by allowing the designer the ability to work in a volumetric space, not just 2D planar area using non body-of-revolution and asymmetric configurations [78].…”

Accurate measurement of the input impedance of bow-tie antenna by the S-parameter method

“…This problem is caused by the fact that the current distribution on the terminal changes by the hand. The effect of a balanced fed antenna was reported to reduce the influence of holding the terminal by hand [2]. The input impedance of the balanced antenna is measured conventionally by using a balun that forces opposite currents into each part of the radiation elements.…”

Multiband Folded Loop Antenna for Smart Phones

“…Much effort has been devoted to the multiband internal antenna during the past decade, such as planar inverted-F antennas (PIFA), inverted-F antennas (IFA), patch antennas and loop antennas [1]. The conventional PIFA, IFA, and their variants have become popular in most handsets and portable devices for mobile phone applications.…”

“…This is necessary, especially as the mobile device is quite small. However, the current variation due to the device being hand-held and the resulting body proximity effect degrades antenna performance since the resonating currents are spread out over the system ground plane [1,10]. To avoid degrading antenna performance, a printed loop antenna is another candidate for the mobile phone since the current induced on the ground plane is small [11][12][13][14][15][16][17].…”