| 摘要 |
A compensation amplifier for an automobile antenna utilizing, as an antenna element, a heating wire incorporated in an automobile rear window, for removing fog formed thereon, is connected between the heating wire and a radio receiver circuit, so as to compensate for a signal transmission loss. An AM band-pass filter coil (La1), a cancelling coil (Lc), and an FM band-pass filter coil (Lf1) are connected between the heating wire (H) and the battery (B). The FM band-pass filter coil (Lf1) and the AM band-pass filter coil (La1) are wound on a toroidal core with air gaps. A floating capacitor (Cs) is connected between the heating wire (H) and a ground potential terminal. The FM band-pass filter coil (Lf1) and floating capacitor (Cs) are used as a part of an input band-pass filter for an FM signal compensation circuit. The AM band-pass filter coil (La1), the floating capacitor (Cs), and an additional capacitor (Cb) are used as a part of an input band-pass filter for an AM signal compensation circuit. |
