A dual-function sensing and communication microwave system that uses a two-port radio frequency (RF) system consisting of a microwave sensor and dual antenna for Beyond Fifth Generation (B5G) application has been investigated. A frequency selective multipath filter (FSMF) achieves the working of these two systems simultaneously through a single port. The selective allowance of required frequency components is achieved by implementing necessary filters on either side of a T-junction, where the two antenna systems are placed at each end. They are measuring the frequency of the distance between two connected sensors to improve the sensor’s performance. The antenna operates at 3.7349 and 2.215 GHz for wireless communication and resonates at 1.995 and 3.98 GHz for microwave sensing. The design and performance of low-pass filter (LPF) and high-pass filter (HPF) to provide minimum impact on the product. A well-designed combination of sensing and communication functions provides a compact, efficient, and versatile microwave system.