RF Channel-Selectivity Sensing by a Small Antenna of Metamaterial Channel Filters for 5G Sub-6-GHz Bands

In this paper, a new small antenna is suggested for 5G Sub-6-GHz band mobile communication. It can change the channel among the three given bands (called the 3.5-GHz area), as a wide-band antenna is connected to a small multiplexer comprising three metamaterial channel filters. The function of channel selection of this antenna system is experimentally demonstrated to prove the validity of the presented scheme. The channel selection for 5G mobile communication is conducted from f(1) (channel 1) through f(2) (channel 2) to f(3) (channel 3), when TX and RX antennas with gains over 0 dBi and S(11) less than −10 dB are located far-field apart (R(Far) ≫ 2.1 cm), and result in the transmission coefficient (S(21)) being the greatest at the selected channel, which is detected by a vector network analyzer.