Design Of Dielectric Waveguide Filter For 5G Applications

With the rapid development of wireless communication technology,China has officially entered the 5G era.Compared with 4G communication,5G communication technology has incomparable advantages,such as higher network transmission rate,lower delay,etc.The application of 5G in the field of Internet of Things will greatly improve the convenience and comfort of peoples lives.As an important component of the wireless communication receiving end,the microwave filters main function is to select the frequency of the received signal.The size of the traditional metal waveguide filter is too large,which is not conducive to integration in modern microwave circuits.The dielectric waveguide filter has important research significance in the 5G communication era because it can achieve miniaturization design and carry large power,and has the characteristics of high Q value and low insertion loss.In view of the above background,this thesis researches and designs dielectric waveguide filter.The main work is as follows:1.A fourth-order cross-coupled dielectric waveguide filter working in 5G frequency band is designed,which is composed of four dielectric waveguide resonators and fed by coaxial probe.The final design size is 24mm×24mm×7.1mm.The center frequency point of the filter is 3.505 GHz,the3dB bandwidth is 250 MHz,the return loss is below-16.5dB,and the insertion loss is less than0.1dB.Three out-of-band transmission zeros were generated by cross-coupling,which were located at 3.36 GHz,3.76 GHz,and 3.88 GHz.2.A sixth-order cross-coupled dielectric waveguide filter working in 5G frequency band is designed with a design size of 53.6mm×25.8mm×8mm.The central frequency point of the filter is3.485 GHz,the 3dB bandwidth is 210 MHz,the return loss is below-17.5dB,and the insertion loss is less than 0.1dB.3.An eighth-order cross-coupled dielectric waveguide filter working in 5G frequency band is designed.The final size of the filter is 48mm×23mm×8.2mm,which is arranged by U-shaped cavies.The central frequency point of the filter is 3.505 GHz,the bandwidth of 3dB is 250 MHz,the return loss is below-16 dB,and the insertion loss is less than 0.2dB.The cross coupling produces three out-of-band transmission zeros,which are located at 3.37 GHz,3.74 GHz and 3.78 GHz respectively.A cross-coupled fourth-order dielectric waveguide filter with a staggered double-blind hole structure is designed to generate symmetric out-of-band transmission zeros at 3.36 GHz and 3.69 GHz,respectively.The final design size is 24.8mm×24.8mm×7.1mm,the central frequency point is3.515 GHz,the 3dB bandwidth is 270 MHz,the return loss is below-15 dB,and the insertion loss is less than 0.2dB.