| 摘要 |
The IFBPF (80) can variably set a passband width (WF) and an attenuation slope (KF). The bandwidth control circuit (102), which is constituted in hardware, controls the WF in accordance with the receiving state, which is composed of a combination of the receiving electric field intensity, the modulation degree, and the intensity of the adjacent-channel interference. A microcomputer (54) controls the KF on the basis of a program stored in a nonvolatile memory (60) and finely adjusts the effective passband width. Control of the WF contradictory for prevention of audio distortion and control of adjacent-channel interference is required when high modulation and adjacent-channel interference exist in a weak electric field state, and the setting becomes difficult. In this particular case, a configuration in which the KF can be modified by a program allows an advantageous receiving state to be readily obtained. |
