高阻带微波带通滤波器的研制

Development of Microwave Bandpass Filter with High Attenuation in the Stopband

为了提高通信设备的性能,研制了高阻带的微波滤波器。该滤波器由5个高Q值的同轴介电陶瓷谐振器构成的带通滤波器。谐振器之间通过介电基片上的电容相互耦合。在装入外壳前,调整好每个谐振器的谐振频率和耦合电容,之后就不需要再调整,外壳上也没有可调零件,从而保证滤波器结构稳定,性能可靠。用εr=74的介电陶瓷制作出滤波器的性能为f0=982 MHz,Δf=10.9 MHzI,L=3.8 dB,阻带在f0±30 MHz处大于69 dB,远阻带衰减优于70 dB。

A microwave filter with high attenuation in the stopband has been developed to improve the quality of communication devices. The filter consists of five high Q value dielectric coaxial resonators. They are coupled to each other through capacitors on a dielectric substrate. The resonant frequency of each resonator and coupling capacitor between adjacent resonators are adjusted be- fore assembly. The resonators and capacitors then assembled in a housing with no further adjustment, and there is no tuning part on the housing to ensure stable structure and gain reliable properties. The filter has been made of dielectric ceramics with εr equal to 74 ,the center frequency is 982 MHz, passband width 10.9 MHz, insert loss 3.8 dB, attenuation at 30 MHz away from center frequency larger than 69 dB, attenuation at far stopband better than 70 dB.