Ultra-wideband Microwave Device Research

As the information age comes, the wireless communication technology has become a very important indexation to measure the national defense forces of one country. Particularly, because of speedy transmission, large capacity, strong anti-interference ability, ultra-wideband (UWB) technology has a large number of references to military communications, military radar and other fields. In recent years, a growing number of UWB technologies are applied to the field of civil communication, which makes the UWB technology market wider and its prospect broader. Therefore, as an essential part of the UWB technology, the UWB microwave devices become particularly important.In the above context, a lot of paper has been read, and the author found that most of the existing UWB mature technology has high insertion loss, low power capacity or poor band rejection,and so on.In order to overcome the above problem, namely, a UWB directional coupler and a UWB band pass filter have been designed, which is an important position of UWB technology. Using air-filled suspended strip-line, the UWB directional coupler achieves the purpose of high-power capacity. It works from2to8.9GHz, covering4.45octave, the degree of coupling to meet-9.5±1dB and the isolation better than-20dB. UWB band pass filter designed by use of a novel input-output structure and coupling in waveguide. The filter works from3.1to10.6GHz, its insertion loss is less than0.5dB, the reflection is better than-11dB, the band rejection is less than-30dB at1.9GHz and-20dB at11GHz, and its parasitic passband appear after15.5GHz. This UWB band pass filter reaches the requirements of a low insertion loss, high power capacity and good band rejection.Finally, the cause of the errors of the microwave devices and their impact have been analysised, and the possible debugging method for the UWB band pass filter has been explored to increase the product rate and to reduce the costs of the filter processing.