Research On Wideband And Small-Scaled PCB Helical Antenna

With the development of micro-electronics and large-scale integrated circuit, magnitude and ponderosity is becoming the main problem of antennas. As one technology of broadband miniature antennas, it is widely used in many fields because of its agility and currency, it has to endure mechanics pressure and the variety of temperature in some special environments, some helixes have to be designed integrating with mechanism, temperature and electricity. PCB fabrication is the most popular process for electric production. It will appeal to major electric engineers to adopt fully board process once antenna design can be easily included on the PCB. This production yield rate can be improved obviously because the PCB technology is very stable and reliable. PCB helix can replace traditional cylindrical helix easily, it is becoming more and more current due to its durability and simple facture and widely applied in many fields such as satellite communication, microwave transmission, GPS and so on.PCB helix is a new form antenna, very few investigations have been reported so far. But the irregular PCB shape leads to different properties from cylindrical antenna in some ways such as design frequency offset employing traditional formula, resonant frequency affected by dielectric constantεr, the decrease of antenna gain aroused by the lossy PCB as well as the bandwidth most concerned in practical project. An equivalent diameter is first advanced to modify traditional design formula so as to avoid resonant frequency offset; then a broadband is gotten by exploiting nonuniform pitch with Loading networks; finally a lossy transmission model is adopted to analyze helix gain affected by the lossy dielectric with the FEM, experimental results are given to verify the validity of theoretical analysis. De...