| 摘要 |
PROBLEM TO BE SOLVED: To provide a switch circuit which is used for the operation control of an attenuator and a phase shifter, and can make an IC small in size and low in cost by requiring only one control voltage for the switching of an attenuation amount and a phase shift amount. SOLUTION: The switch circuit comprises circuit portions 1 and 2, resistances R11 to R14 and RT0, capacitors C1 and C2, and an NMOS transistor T0. Signals are inputted to and outputted from the switch circuit through RF input/output terminals Vio1 and Vio2. Vref is reference potential and is kept at fixed potential. Resistance between a drain and a source of the NMOS transistor T0 is controlled by changing a control voltage Vc by a control means not shown in Figure. COPYRIGHT: (C)2008,JPO&INPIT
|
