Abstract: The present invention is directed to improve high frequency characteristics by reducing inductance of a source. In an HEMT assembled in a power amplifier device, each of a drain electrode, a source electrode, and a gate electrode is constructed by a base portion and a plurality of fingers projected in a comb-teeth shape from the base portion, and the fingers of the electrodes mesh with each other. In the source electrode, a width of the fingers positioned at both ends of the plurality of fingers is wider than a width of each of the fingers positioned between both ends. The width of each of the fingers positioned at both ends is a width equal to or larger than a sum of the widths of the plurality of fingers positioned between both ends, and the width of the base portion is wider than that of each of the fingers positioned at both ends. An electrode pad provided for the source base portion and an external electrode terminal are connected to each other via a conductive wire.

Abstract: An object of the present invention is to provide an antenna switch circuit that effectively reduces signal leakages at a cross point even at higher operating frequencies and a high frequency module containing said antenna switch module. The antenna switch circuit comprises: a high frequency signal line to transmit a transmitting signal to be input to transmitting terminals to an antenna terminal and also to transmit a receiving signal to be input to the antenna terminal to receiving terminals; switches that are connected in the middle of the high frequency signal line between transmitting terminal and antenna terminal; switches that are connected in the middle of the high frequency signal line between receiving terminal and antenna terminal; and signal lines to transmit control signals for controlling turning on and off of the switches.

Abstract: The present invention miniaturizes a HEMT element used as a switching element in a radio frequency module. A single gate electrode 17 is formed in an active region defined by an element separation portion 9 on a main surface of a substrate 1 comprising GaAs. The gate electrode 17 is patterned so as to extend in the vertical direction of the page surface between source electrodes 13 and drain electrodes 14, and to extend in left and right directions at other portions. Thus, the ratio of the gate electrode 17 disposed outside the active region is reduced, and the area of a gate pad 17A is reduced.

Abstract: 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.

Abstract: The present invention is directed to improve high frequency characteristics by reducing inductance of a source. In an HEMT assembled in a power amplifier device, each of a drain electrode, a source electrode, and a gate electrode is constructed by a base portion and a plurality of fingers projected in a comb-teeth shape from the base portion, and the fingers of the electrodes mesh with each other. In the source electrode, a width of the fingers positioned at both ends of the plurality of fingers is wider than a width of each of the fingers positioned between both ends. The width of each of the fingers positioned at both ends is a width equal to or larger than a sum of the widths of the plurality of fingers positioned between both ends, and the width of the base portion is wider than that of each of the fingers positioned at both ends. An electrode pad provided for the source base portion and an external electrode terminal are connected to each other via a conductive wire.