Modified 16-Quasi Log Periodic Antenna Array for Microwave Imaging of Breast Cancer Detection

In this paper, an effective system for microwave imaging of breast tumor detection using modified 16-planar log periodic antenna (PLPA) array is presented. The modified PLPA operates in the band from 2 to 5 GHz with stable directional patterns in the end-fire direction. Once the results of a single antenna element have been validated, the design is extended to include 16 antenna elements. All 16 transceiver antennas are vertically placed around the phantom in a circular manner where one antenna acts as a transmitter and the rest work as receivers. Delay and Sum (DAS) algorithm is used for post processing the acquired scattered signals from the sensors to reconstruct the image of the breast and to identify the existence of breast tumors. The electromagnetic simulators CST and HFSS are used to design the system, while MATLAB is used to process the data. The developed PLPA array-based microwave imaging system performs admirably, making it one of the most effective systems for detecting tumor cells.

Design of Dual-Polarized Pyramidal Log-Periodic Antenna with Integrated Feed for Additive Manufacturing

A dual-polarized log-periodic antenna with 5:1 bandwidth is considered for wideband, amplitude only direction-finding applications. The proposed system is comprised of two identical, orthogonal, sets of trapezoidal log-periodic arms. The arms’ inclination from planar facilitates reduced back lobe radiation to improve directivity and efficiency once absorber is introduced. One arm of each polarization set contains a variable radius coaxial shell to achieve impedance matching such that the system impedance at the base of the antenna is matched to 50 ohms. Analysis and design for the 3d printed direction-finding antenna system is accomplished using a commercial off the shelf (COTS) finite element method (FEM) solver.

Improvements in Insertion of Auxiliary Parity Segments in WIPL-D All-Quad Meshing Algorithm

This paper provides a new technique that improves the all-quad meshing algorithm implemented in the WIPL-D software. The technique allows for the insertion of required auxiliary segments to achieve parity of a number of segments over all closed loops of all faces. The aim of the improvement is to reduce the total number of mesh elements in the final mesh. The efficiency of the proposed technique is compared to the traditional one mentioned earlier. A reduction in the number of mesh elements of about 15% has been achieved when applied to a log-periodic antenna WIPL-D model.

Ultra-Wideband Trapezoidal Log-Periodic Antenna Integrated with an Elliptical Lens

The design and implementation of an ultra-wideband trapezoidal log-periodic antenna (LPA) integrated with an elliptical dielectric lens are presented. The proposed LPA is fed by an ultra-wideband microstrip-to-coplanar stripline transition structure. In order to improve the radiation patterns and to increase the antenna gain, an elliptical dielectric lens is mounted on the top of the LPA radiator. The design parameters of the elliptical lens integrated with the LPA were optimized through a parametric analysis. The proposed antenna shows an impedance bandwidth (S11 ≤ −10 dB) from 5.2 to 40 GHz, with a peak gain of 17.8 dB.