X-band uygulamaları tasarım ve geniş bant meandering anten imalatı

Novel meandering antenna designs have been proposed for broadband communication applications in X-band spectral region. Broad band antennas are becoming more popular as a result of growing demand for bandwidth, for example, video conferencing; direct sequence spread spectrum (DSSS) communication system and frequency hopping. Meanders introduce longer current paths and hence add multiple staggered resonating modes. This design technique can be used to achieve multiband designs using resonating modes far from each other. However, if the design is engineered to let these resonant modes come closer to each other, they will complement the effect of closely spaced resonances, forming staggered resonating behavior, and broadband antennas are achieved. Current in the adjacent arms of the meandering antennas cancel out each other due to symmetry of the design, and radiation efficiency is compromised as a result. Antisymmetric meandering arms are presented in this work, to achieve higher radiation efficiency. A relationship between physical dimensions of the meandering loops, that is, height, thickness, mutual coupling and material properties are presented and resonant frequencies are mathematically modeled. The physical dimensions are selected to obtain set of resonant frequencies, which are closely spaced in the frequency spectrum. The model is simulated using finite element method (FEM) numerical modeling technique. A good agreement between mathematically calculated resonant response and simulated results is obtained for different designs geometries. Six designs are modeled and fabricated on a single sided FR4 substrate of dielectric constant 4.4 and thickness 1.6 mm. In order to evaluate the performance for suitable comparison, each antenna is identically implemented using a 50-Ohm coplanar waveguide (CPW) as feeding probe. Antennas are independently assessed using a Network Analyzer. Both S11 and S12, VSWR, efficiency, gain and bandwidth (BW) parameters are measured. The overall performance of the antennas has been found good.