Design And Study Of Ultra Wide Band Ridged Horn Antenna

In recent years ultra-wideband technology, which has gradually turned from the military field to civil field, with its high rate, large capacity and anti-multipath effect has a very good application prospects. Ultra wide band (UWB) antenna, which is different from traditional broadband antenna, needs to not only cover broadband frequency domain, but also have a excellent response in the time domain, so that it can be transient pulse signal's radiator and receiver. The performance of UWB antenna significantly constrains the UWB communication system.This paper studies the ridged horn antenna suitable for the modem UWB impulse radio system, from both of the frequecny domain angle and time domain angle. The ridged-horn antenna has a so wide bandwidth, good directional characteristics in its major radiation angle, that it can radiate and receive transient pulse signal with little distortion, and such antenna can not only applies to individual structure, but also can include in the antenna array as a basic array elment.The difference between the UWB pulse radiation antenna and traditional wideband antenna is introuduced, as well as time domain ultra broadband antenna technical system. This paper introduces the characteristics of the phase center and the concept of group delay, and detailed ridged-horn antenna theory.Two UWB horns, which can be used in radio monitoring for microwave spectrum detecting and direction finding, is proposed. The double ridged horn can cover a wide frequency band from 850MHz up to 11.3GHz and achieve high gain. The antenna is derived from the traditional pyramidal horn in which extra ridges are placed. It is fed by coax-to-ridged-waveguide, which is optimized for good matching. It shows that the VSWR (Voltage Standing Wave Ratio) is lower than 2, gain is 8-13dB and stable pattern is acheived in a broad band. The quard-ridged horn can also cover broadband frequency domain, from 1.06GHz to 11.2GHz, achieve high gain, and generate dual polarization.Finally, the ridged horn antennas designed in this paper are simulated in CST. The simulation result proves out that these antennas are available for the UWB radio system.