| 摘要 |
PURPOSE:To improve reception characteristics in a strong electric field and a weak electric field by providing an amplifying part, an attenuating part, a tuning control part, and an antenna switching part, which are controlled by a receiver body, near a pair of glass antennas. CONSTITUTION:A pair of glass antenna patterns 11a and 11b are buried in a rear glass 11 of a vehicle. An antenna switching and amplifying part 12 having a diversity antenna switching part 13, an electronic attenuator 14, an input tuning circuit 15, and an RF amplifier 16 is provided near these antenna patterns. Signals are sent from a receiver body 18 provided on a dashboard by a signal line 24, and diversity switching is set to a diversity switching set circuit by the output of an IF demodulating part 20, and the electronic attenuator 14 and the RF amplifier 16 are controlled by the AGC signal of an RF stage 19, and the input tuning circuit 15 is controlled by the output of a PLL part 22. The output of the IF demodulating part 20 is amplified as voice by an amplifier 21 to drive a speaker 23. Thus, a sufficient diversity effect is obtained in a weak electric field region, and overload is prevented in a strong electric field region, and reception characteristics strong against interference are attained. |
