Design and construction of conical multimode horn with a choke

In this paper, an improved conical horn is designed which used as a feed in antenna for telemetry and command system. The conical horn is calculated by the method of finite-element method (FEM). Modes of electromagnetic field existing in the conical multimode horn with a choke are analyst, the design of a coaxial to waveguide transition and the simulation results of radiation pattern are given. Experiment results of conical multimode horn with a choke agree with the designing value at the C-band. It is shown that the feed is not only a main lobe which is symmetrical with respect to rotation, but also a uniform phase centre of the E plane and H plane, low Voltage Standing Wave Ratio (VSWR) which is less than 1.1 at centre frequency and less than 1.5 in 500 MHz bandwidth.