Two kind of conical conformal GPS antenna arrays on projectile

Two kind of GPS (Global Position System) omnidirectional antenna array which is conical conformal with revolving projectile is researched. One is quadrifilar helix antenna on rotary table and the other microtrip antenna conformal to the same rotary table. The basic theory and design method of antenna arrays are described. The radiation characteristic of the antenna arrays is presented and they are simulated by the software Ansoft HFSS. The theory and simulation results are given to illustrate that the two kind antenna arrays can radiate an omnidirectional pattern normal to the axis of the cylinder approximately, and the comparisons between them are made.