W-band endfire log periodic dipole array

A W-band endfire log periodic dipole array (LPDA) antenna designed to be compatible with a surface micro-machining process known as PolyStrata™ is demonstrated in this paper. 13 dipole elements are crisscrossed in two copper layers to form the log periodic array. A μ-coaxial line is monolithically integrated in the antenna´s lower boom as the feeding line. The proposed antenna achieves consistent radiation patterns, VSWR<;2, and gain>;7dBi from 70 GHz to 115 GHz. A two element LPDA based array with monolithically integrated 180° hybrid is also demonstrated. The W-band LPDA antenna is slightly modified to cover 50 GHz to 110 GHz bandwidth. The radiation patterns of sum and differential modes show good gain and null-depth in the end-fire direction, respectively. The performance of the designed antenna is verified by finite integration and finite element method comparisons.