| 摘要 |
When a coil 1 b is arranged at the forward end of an antenna element 1 a which resonates with the frequency band of portable phones and an effective length of the combination the antenna element 1 a and coil 1 b is set equal to the length at which the frequency band of FM broadcast resonates, the coil acts as low impedance, matching to the frequency band of FM broadcast, and acts as high impedance for the frequency band of portable phones which is higher than the frequency band of FM broadcast. Consequently, the coil 1 b can serve both as a matching coil for passing the frequency band of FM broadcast and a trap coil for blocking the passage of the frequency band of portable phones.
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