2．4GHz波段微带发夹型带通滤波器设计与馈电研究

介绍了微带发夹型带通滤波器的基本原理，基于ADS软件设计了微带发夹型带通滤波器，实测与仿真结果吻合较好，中心频率为2．4GHz，相对带宽大于5％，适用于短距离无线通信频段。研究了微带发夹型带通滤波器直接馈电的3种形式对S参数仿真结果的影响，均匀阻抗馈电、高低阻抗馈电、阻抗渐变馈电3种形式的馈电的仿真结果都满足设计要求，采用高低阻抗、渐变阻抗馈电的S参数仿真结果大体一致，略优于均匀阻抗馈电。设计的微带发卡带通滤波器具有设计简单、结构紧凑、插损较小的优点，可用于短距离无线通信。

2.4 GHz band Hairpin Microstrip Bandpass Filter Design and Feed Research

The fundmental of hairpin microstrip bandpass filter was introduced in this paper, then the microstrip bandpass filter had been designed by ADS. The simulated and measured results have a good agreement, the bandpass filter＇ s center frequency is 2.4 GHz, relative bandwidth is greater than 5 percent, it is suitable for short distance wireless communication frequency band. Besides, the effects of three kinds of forms of the microstrip hairpin type bandpass filter＇ s direct feeding have been researched mainly on the simulation results of S parameters, the three kind of bandpass filters of uniform impedance feed, high- and low-impedance feed, impedance gradient feed are designed and simulated, which all meet the design requirement. Among all of these, the simulated results of high- and lowimpedance feed, impedance gradient feed are the same, is slightly better than the uniform impedance feed. Generally speaking, the fabricated mierostrip hairpin bandpass filter is also simple in design and compact in structure, has lower insertion, so it has higher practical value, and the design of the feed structures has certain engineering significance.