Investigating obstacle problems for elastic rods we are sometimes confronted with the question to look for a solution which has a prescribed shape along some part of it. In the simplest case the rod is enforced to be straight along some contact area (cf., e.g., Gastaldi & Kinderlehrer [3]). Motivated by such applications we study straight configurations of elastic rods in this paper. More preci...

recently a new structure called groove gap waveguide (GGW) is ‎introduced to implement low loss microwave component devices ‎especially for millimeter wave applications. This paper presents a ‎new type of H-plane horn antenna making use of this new technology ‎in which backward radiation is significantly suppressed by ‎introducing a high impedance surface at the antenna aperture. The ‎high impe...

A newly designed printed slot antenna is presented that incorporates variable two band-notched functions for ultra-wideband (UWB) applications. The two band notches of this coplanar waveguide (CPW) fed antenna are achieved by an M-shaped slot (MSS) embedded in the radiating element and a C-shaped strip (CSS) close to ground plane, therefore two very narrow rejected properties in the wireless lo...

This paper presents a new approach for design of the log-periodic dipole array antenna (LPDA) based on using of different design parameters in the LPDA elements to control the antenna behavior. In the proposed procedure, the design parameters can control the value of forward gain over the operating frequency range, and also adjust the gain flatness. Furthermore, this design procedure can decrea...

An analytical technique is proposed for estimation of the radiation pattern of inverted-F antenna (IFA) which is mounted on the side wall of a long cylinder. The method can be applied to describe the IFA radiation in a lot of practical cases. It is indicated that this radiation pattern is a combination of radiation patterns of a horizontal and a vertical small radiator, near the cylinder with a...