Research And Design Of A New Kind Of Two Step Dielectric Low And High Pass Filters

With the rapid development of the mobile communication industry, the frequency bands is divided more detailed, the availability path of frequency bands is more crowd, The whole microwave industry comes into the times of low profit also. The microwave filters need more excellent and cheap, especially the Attenuation needs deeper and the volume needs smaller.The paper advances a new kind of two step dielectric low and high pass filters, then analyses the transfer characteristic of filters, designs and produce a new kind of low and high pass filters base on a new structure of dielectric coaxial stepped impedance resonator (SIR) of quarter wavelength. The results of computer simulation and experiment test results show the cut-off frequency of the low pass filter under normal temperature is1.2GHz, the insertion loss in band is smaller than2.0dB, VSWR (Voltage Standing Wave Ratio) is smaller than2.0; the cut-off frequency of the high pass filter under normal temperature is1.22GHz, the insertion loss in band is smaller than2.0dB, VSWR is smaller than2.0. This kind of filters is smaller and than before, the cut-off rate is also more excellent. The original design requirement is reached.