Manish A. Hiranandani

Widening Butler matrix bandwidth within the X-band

Electronic scanning of antennas is accomplished using beam forming networks (BFNs). A widely used BFN is the Butler matrix, a circuit type beam former. The conventional Butler matrix consists of hybrids and phase shifters. Since they are constructed with simple transmission lines, they are inherently narrow band structures. A novel design of Butler matrix is presented, which enhances the bandwidth by using broad banding techniques to obtain wider bandwidth performance from the transmission point of view. Problems encountered in designing such networks at high frequencies are addressed.

Hard and soft surfaces realized by frequency selective surfaces on a grounded dielectric slab

New designs of hard and soft surfaces realized by dipole and slot frequency selective surfaces (FSS) implemented on a grounded dielectric slab are presented. These structures act as GO or STOP surfaces for transverse electric (TE) and transverse magnetic (TM) polarizations, respectively, depending on the direction of a plane wave excitation. Multi-band and dual polarized designs are proposed based on the use of FSS structures with different resonant lengths and orientation of dipoles and slots. EMPiCASSO commercial software is used for the full-wave analysis of presented FSS configurations.

Fast design of Rotman lens and its application in Rotman-DRA phased array

For fast design of Rotman lens the symmetry plane is used to reduce the structure size, but solved twice. One solution with the symmetry plane as electrical wall and the second with magnetic wall are used. Then process the s-parammeters from both solution to obtain the s-parameters for the original lens for even or odd number of ports. A wideband Rotman lens for 6-18 GHz and beam scanning capability of ±37 is presented. The lens is used with wideband rectangular DRA array.

Impact of wave polarization on MIMO platform performance in the wireless home environment

In this study we present a simulation framework for modeling the antennas spatial interaction with the propagation channel, derived and modeled from measurement campaigns. We present an application of the analysis in the 2400 MHz band. The antennas interaction with the channel is considered in both vertical and horizontal polarizations. The resulting metrics - channel condition number, and system data rate - serve to quantify system performance as a function of antenna design and placement.