JPS556977A - Composite antenna - Google Patents

Abstract

PURPOSE:To obtain a composite antenna which is capable of transmission and reception of more than two signals of different frequencies as well as the facilitated miniaturization. CONSTITUTION:High frequency signals fH fed from feeder terminals 5a and 5b are supplied to high frequency coupling coil 12 with no loss virtually via capacitors 14a and 14b. Thus the high frequency electromagnetic field is generated at radiation element 11, and the electromagnetic waves are radiated into the space. In this case, high frequency signals fH are generated across low frequency coupling coil 13 by the high frequency electromagnetic field. But no high frequency current flows to coil 13 since the passage of the high frequency signals is blocked by choke coils 15a and 15b, and accordingly no evil effect is given to the radiation action of signal fH. On the other hand, low frequency signals fL supplied from feeder terminals 6a and 6b are fed to the low frequency coupling coil with no loss substantially via coils 15a and 15b. Thus the low frequency electromagnetic field is generated to element 11, and this inductive magnetic field is radiated into the space.