MULTI-BAND FILTER DESIGN SOLUTION WITH AUTOMATIC SIGNAL DECOMPAIRING

Abstract

The bandpass filters for metric and decimetric wavelengths play a crucial role in radar and military communication systems, where information transmission and reception must occur under stringent conditions with high accuracy. On the other hand, many specific devices do not utilize the entire frequency band but instead operate within specific frequency ranges within the band. Therefore, the design of bandpass filters to optimize the ability to receive and transmit data within these specific frequency ranges, eliminate noise signals, and prevent counterfeit information is essential and urgent. This ensures security and efficiency in military and defense operations, aligning with current requirements. Additionally, to meet the diverse requirements for precise frequency selection across different frequency ranges while maintaining compact device structures, the research team has designed an automatic electronic switching mechanism. This mechanism enables the use of multiple filters in different frequency bands with a single signal input. In this study, the authors designed Elliptic bandpass filters for the frequency ranges of (100 ÷ 150) MHz and (220 ÷ 400) MHz. Simultaneously, an automatic electronic switching mechanism was developed to meet the desired criteria for the cutoff frequency of each branch, insertion loss, and return loss at the ports. This allows the use of two filters in different frequency bands with a single signal input