| 摘要 |
An antenna system comprises at least two ferrite bar antenna elements, each of which includes: a ferrite bar 7 - 10, a first coil 15 for a first frequency and a second coil 16 for a second frequency. The said coils 15, 16 are wound on each respective ferrite bar 7 - 10 at separate positions to one another. Four ferrite bar antenna elements 7 - 10 may be arranged in a square formation in a common plane where two of the bar elements 7, 8 are oriented along an x-axis and the other two 9, 10 along a y-axis. The antenna elements may be surrounded by an electrostatic shield formed by printed conductive patterns formed on circuit boards. The first coil 15 may be a medium frequency, 490 - 518 kHz, coil combined with a tuning capacitor 17 and the second coil 16 may be a high frequency, 4209.5 kHz, coil with a tuning capacitor 18. The said coils 15, 16 provide output signals to respective amplifiers which may use a circuit, which includes a low pass and high pass filter, to simultaneously provide the two output signals via a common signal output terminal. |
