| 摘要 |
A front-end IC is so structured that an RF circuit section and a digital demodulating circuit section are integrated in one package therein. The RF circuit section has an RF circuit section and a base band variable gain amplifier. The digital demodulating circuit section has an amplification rate control circuit. The front-end IC is also provided with an AGC signal input switch for switching between (a) inputting an internal signal, via an AGC loop, into the RF circuit section in the RF circuit section and the base band variable gain amplifier, and (b) directly supplying a test-use AGC signal, by opening the AGC loop, into the RF circuit section in the RF circuit section and the base band variable gain amplifier. The internal signal is outputted from the digital demodulating circuit section. The AGC signal input switch is switched over in accordance with an AGC signal input switching signal TEST. With this arrangement, it is possible to provide an IC in which a test of amplification rate property of the variable gain amplifier included in the RF circuit, and other tests of the RF circuit can be performed easily.
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