| 摘要 |
PROBLEM TO BE SOLVED: To provide a RF switch circuit and an antenna shared unit, which can obtain satisfactory isolation and a satisfactory insertion loss. SOLUTION: The RF switch circuit 31 changing over an antenna ANT for transmission and reception is provided among an antenna terminal ant, a transmission filter 1 and a reception filter 2. In the RF switch circuit 31, a first diode D1, aλ/4 phase circuit 4 and a second diode D2 are connected in series in the order. The anode of the diode D1 is connected to the output terminal of the transmission filter 1 and a control terminal CONT. The cathode of the diode D1 is connected to the antenna terminal ant and the anode of the diode D2 is connected to the output terminal (a) of theλ/4 phase circuit 4. The cathode of the diode D2 is connected to ground through the parallel circuit of a capacitor C1 and an inductance L1.
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