Compact Multichannel Filter With Improved Bandwidth for Vehicular Communication System Application
Michael Wilson Aidoo, Kaijun Song, Yong Fan · IEEE Transactions on Vehicular Technology · 2024
In this paper, an approach is proposed for the realization of a compact third-order multi-channel filter based on fractal-shaped creased resonators (F-SCRs) and complementary coupling. Three resonators each were employed by this approach to achieve the desired third-order filtering responses in all the channels. The even-and odd-modes of the microstrip SIR structure were utilized to achieve a simple filtering response in each channel. The main resonators have a combination of a fractal-shaped line and a uniform impedance resonator, which are combined and analyzed in an asymmetric SIR structure framework. The center frequency and bandwidth of the desired channels were kept the same by selecting similar resonators with equal parameters across all channels. The proposed circuit was optimized and fabricated for measurements at a center frequency of 2.5 GHz. A total size of 0.46λg×0.46λg was achieved. Isolation levels of 23dB, insertion loss better than 1.02dB and return losses better than 20dB have been measured. There is a conformity of the measured responses to the simulated responses. There is a fractional bandwidth of 15% realized in this proposition. Therefore, this proposed six-channel bandpass filter circuit has been validated for integration and application in vehicular communication systems.