並列摘要
In this paper, a novel spur-free low pass filter suppressing harmonics is proposed. This low pass filter has a broad stop band and a high rejection ratio which can meet the requirements for modern wireless communication systems. Furthermore, the filter shows a very sharp attenuation slope above the cutoff frequency and a low insertion loss in the pass band, and is quite small compared to stepped impedance low pass filters of the same order. The design formula of this novel low pass filter is based on the equivalent circuit of coupled lines and transmission lines. The filter is evaluated by an IE3D electromagnetic simulator. The simulated data are in good agreement with the experimental results.