EARPHONE ANTENNA AND RADIO DEVICE WITH SAME

摘要

An earphone antenna hardly producing a high-frequency adverse effect on a radio device from the human body through the earphone, ensuring a reception sensitivity necessary for the signal of a broad band frequency without needing adjustment of the sensitivity, and capable of transmitting an audio signal of a television receiver to the earphone unit. Two pairs of audio/high-frequency signal lines (8La, 8Lb, 8Ra, 8Rb) corresponding to left and right earphone units (12L, 12R) connected to a balance-unbalance transformer (4) are provided. The terminals of the audio/high-frequency signal lines (8La, 8Lb, 8Ra, 8Rb) on the opposite side to the balance-unbalance transformer (4) are connected to the earphone units (12L, 12R) through loading coils (LLa, LLb, LRa, LRb). Further, the terminals on the opposite side are interconnected through a pair of conductors (20a, 20b). The impedances of the loading coils (LLa, LLb, LRa, LRb) are low to a fundamental frequency and high to a specific frequency higher than the fundamental frequency to cut off the specific frequency. The audio/high-frequency signal lines (8La, 8Lb, 8Ra, 8Rb) are used as transmission means for audio signals to the earphone units (12L, 12R).