Implementation of high performance and broadband crossover junction in butler matrix design

Directional networking provides several advantages including extended range, increase capacity, security and power efficiency over other communication networks using Omni-directional antenna. Recently, a narrow beam dual-pol long slot antenna array with 4-6 GHz operating frequency band was developed for directional networking [1]. To steer the main beam of the antenna array, Butler matrix was proposed to feed the antenna array with linear phase shifts in because of the low cost and simplicity advantages it provides. To reduce the size and improve the performance of the Butler matrix, a compact broadband crossover junction [2] was implemented in an 8×8 Butler matrix that operate in 4-6 GHz frequency band. In this paper the design of the 8×8 Butler Matrix is described and characteristic of a developed prototype are presented. It is shown that measured results on the developed prototype agreed very well with the simulated results over the entire band for 4-6 GHz.