Electric component for communication device and semiconductor device for switching transmission and reception
View Patent ↗There are provided a transmission/reception switching circuit which is small in insertion loss and harmonic distortion and allows an increase in the output power of a power amplifier and an electronic component for communication on which the transmission/reception switching circuit is mounted. As an element composing a transmission/reception switching circuit in a wireless communication system, series-connected FETs or a multi-gate FET are used in place of a diode. Gate resistors connected between the individual gate terminals and a control terminal are designed to have resistance values which become progressively smaller from the gate to which a highest voltage is applied toward the gate to which a lowest voltage is applied.
1. An electronic component for communication, comprising:
a first power amplification circuit for amplifying an RF signal in a first frequency band to be transmitted;
a second power amplification circuit for amplifying an RF signal in a second frequency band to be transmitted;
a first terminal connected to a transmission/reception antenna;
a second terminal connected to a first reception circuit for processing a received RF signal in the first frequency band;
a third terminal connected to a second reception circuit for processing a received RF signal in the second frequency band;
a first switch circuit provided between said first terminal and said first power amplification circuit and between said first and second terminals; and
a second switch circuit provided between said first terminal and said second power amplification circuit and between said first and third terminals,
wherein a transistor constituting said first switch circuit and a transistor constituting said second switch circuit have respective characteristics different from each other such that an insertion loss of the first switch circuit and an insertion loss of the second switch circuit are balanced,
wherein said first switch circuit includes first switching means provided between said first terminal and the first power amplification circuit and second switching means provided between said first and second terminals, and
wherein said second switch circuit includes third switching means provided between said first terminal and the second power amplification circuit and fourth switching means provided between said first and third terminals, each of said second and fourth switching means is constituted by a single multi-gate transistor or a plurality of transistors connected in series, respective resistor elements are connected between a plurality of gate terminals of the transistor or transistors and an control input terminal used commonly thereamong, and resistance values of the resistor elements have been set such that the resistor element connected to the gate terminal closer to said first terminal has a larger resistance value.
2. An electronic component for communication according to claim 1 , wherein each of the first and third switching means is comprised of the single multi-gate transistor or the plurality of transistors connected in series, the respective resistor elements are connected between the plurality of gate terminals of the transistor or transistors and the control input terminal used commonly thereamong, and the resistance values of the resistor elements are set such that the resistor element connected to the gate terminal closer to said first terminal has a smaller resistance value.