The MULTI FREQUENCY COMBINER is mainly used to combine multiple signals into a single distribution system. For instance, FM radios with frequencies ranging from 88 to 108MHz, walkie-talkies with frequencies from 136 to 174MHz, public security walkie-talkies with frequencies from 350 to 370MHz, and walkie-talkies with frequencies from 400 to 430MHz, as well as multiple systems such as 2G, 3G, and 4G mobile phones, share the antenna feed section. For example, in tunnels, they share leaked cables to transmit signals of various frequencies, thereby reducing costs.