论文部分内容阅读
提出了一种阻带具有多个传输零点的带通滤波器设计方法,基于低温共烧陶瓷(LTCC)技术实现,可满足移动通信用滤波器小型化、高性能的要求。在电路设计中,通过改进滤波器谐振器结构,分别在阻带的低端近端、高端远端引入传输零点以提高带外抑制。借助三维仿真软件,进行指标、结构的仿真优化,设计并制作了一款尺寸为6 mm×3 mm×2 mm的LTCC滤波器,其中心频率f0=2.25 GHz,0.5 dB带宽不小于100 MHz,通带内损耗不大于1.8 dB,在1.33,1.78 GHz和二次谐波处均有传输零点。实测结果表明,该滤波器在阻带低端和二次谐波处有较好的抑制,因此其在移动通信系统中会有广泛应用。
A bandpass filter design method with multiple transmission zeros in the stop band is proposed. It is based on the low temperature co-fired ceramic (LTCC) technology to meet the requirements of miniaturization and high performance of mobile communication filters. In the circuit design, by improving the structure of the filter resonator, the transmission zero is introduced respectively at the low end and the high end of the stopband to improve out-of-band rejection. With the aid of 3D simulation software, the LTCC filter with the size of 6 mm × 3 mm × 2 mm was designed and fabricated by simulation and optimization of the index and structure. Its center frequency f0 = 2.25 GHz, 0.5 dB bandwidth is not less than 100 MHz, The passband loss is not more than 1.8 dB and there is a transmission null at 1.33, 1.78 GHz and the second harmonic. The experimental results show that the filter has better rejection at the lower stopband and second harmonic, so it will be widely used in mobile communication system.