Abstract: In a receiving unit, an AGC circuit controls the gain of a high frequency amplifier based on an output signal of a mixer, that is, an intermediate frequency signal obtained before an unnecessary frequency component is removed by a BPF. Therefore, deterioration in the distortion characteristic of the mixer can be suppressed more effectively than a conventional case where the gain of the high frequency amplifier is controlled based on an intermediate frequency signal that has passed through the BPF and amplified by an intermediate frequency amplifier.

Abstract: An analog/digital-compatible front-end module comprises a high frequency amplifier 9 for amplifying a high frequency signal received by an antenna 1; a frequency converter circuit 11 for frequency-converting an output signal from the high frequency amplifier 9 to output an intermediate frequency signal; an analog demodulator 5; a digital demodulator 6; an analog/digital switch 4 for selectively feeding an output signal from the frequency converter circuit 11 to the analog demodulator 5 or to the digital demodulator 6; and an AGC signal switch 7 for controlling gain of the high frequency amplifier 9 in accordance with a gain control signal obtained from the analog demodulator 5 during an analog broadcast reception, while controlling gain of the high frequency amplifier 9 in accordance with a gain control signal produced from the output signal from the frequency converter circuit 11 during a digital broadcast reception.

Abstract: An analog/digital-compatible front-end module comprises a high frequency amplifier 9 for amplifying a high frequency signal received by an antenna 1; a frequency converter circuit 11 for frequency-converting an output signal from the high frequency amplifier 9 to output an intermediate frequency signal; an analog demodulator 5; a digital demodulator 6; an analog/digital switch 4 for selectively feeding an output signal from the frequency converter circuit 11 to the analog demodulator 5 or to the digital demodulator 6; and an AGC signal switch 7 for controlling gain of the high frequency amplifier 9 in accordance with a gain control signal obtained from the analog demodulator 5 during an analog broadcast reception, while controlling gain of the high frequency amplifier 9 in accordance with a gain control signal produced from the output signal from the frequency converter circuit 11 during a digital broadcast reception.

Abstract: A shield case includes first and second side plates formed by blanking a metal sheet. Between the first side plate and the second side plate, two shield plates are formed connected to the side plates through connecting portions. One shield plate has, in one end edge, a protuberance and, in the other end edge, a shield plate formed through a connecting portion. Bending allowances are formed respectively in the first and second side plate in areas between the connecting portions. During assembling, the bending allowances of the first and second side plates are bent inward between the shield plates.

Abstract: A shield case includes first and second side plates formed by blanking a metal sheet. Between the first side plate and the second side plate, two shield plates are formed connected to the side plates through connecting portions. One shield plate has, in one end edge, a protuberance and, in the other end edge, a shield plate formed through a connecting portion. Bending allowances are formed respectively in the first and second side plate in areas between the connecting portions. During assembling, the bending allowances of the first and second side plates are bent inward between the shield plates.