Performance Improvement of Ear-Bar TWS Earphone Antenna Using Parasitic Metal

An ear-bar TWS earphone antenna with improved ear-To-ear path gain (PGE2E) and efficiency is presented. The proposed antenna consists of an inverted-L antenna and a parasitic metal. By applying the parasitic metal, the vertical electric field (E-field) around the head is enhanced and the E-field into the human head is weakened. Due to the stronger vertical E-field around the head, the proposed antenna achieves enhanced PGE2E. Also, for the weak E-field in the head, the improved antenna efficiency is realized. Two prototypes without and with the parasitic metal are fabricated and measured. The measured-6 dB bandwidths of the two prototypes can cover the ISM band. With the help of the parasitic metal, the measured average efficiencies on the head within the 2400-2484 MHz band are improved from 19.1% to 30.9%. In the meanwhile, the measured PGE2E on the head has improved from-56 dB to-49.7 dB. The proposed ear-bar TWS earphone antenna with enhanced PGE2E and efficiency is promising for practical applications.