AMPLIFIER AND DOHERTY AMPLIFIER USING THE SAME

• Main Authors: YAMAUCHI KAZUHISA, ISHIZAKA SATORU, NAKAYAMA MASATOSHI, OTSUKA HIROSHI
• Format: Patent
• Language: English
• Published: 04.09.2008
• Subjects: AMPLIFIERS; BASIC ELECTRONIC CIRCUITRY; ELECTRICITY

PROBLEM TO BE SOLVED: To provide an amplifier wherein RF loss is extremely small, the matching condition of an FET is not affected even when the equivalent resistance of a diode is changed and a current consumed in a bias circuit is little, and to provide a doherty amplifier using the amplfier. SOLUTION: The amplifier is provided with a field effect transistor for amplifying inputted signals, a voltage dividing circuit for dividing a voltage inputted from the outside to both ends of the circuit, and a connection circuit for leading a part of the inputted signals to the voltage dividing circuit and supplying the divided voltage to the gate electrode of the field effect transistor. The voltage dividing circuit is composed of serially connected at least one diode and resistor, the diode is biased in a forward direction, and the equivalent resistance is changed by detecting the led signals. The connection circuit is composed of a resistor or an inductance, and a capacitor is not connected to the connection point of the voltage dividing circuit and the connection circuit. COPYRIGHT: (C)2008,JPO&INPIT