Patent ID: 9543898
Date: 2017-01-10
CPC Classifications: H03F

Claim:
1. A microwave amplifier for amplifying a microwave signal using an active element comprising: a bias circuit including, a resonant circuit including a resistor and a second capacitor element connected in series between the ground and the terminal where the line is connected to the bias voltage source, wherein the first capacitor element has a reactance regarded as being short-circuited at the frequency configured to be amplified, the resistor has a resistance value lower than an absolute value of an impedance of the first capacitor element at a frequency of a beat signal generated between a lowest frequency and a highest frequency in a communication band of the microwave amplifier, an inductance of the line, the resistor, and the second capacitor element constitute a resonant circuit at a frequency of the beat signal generated between the lowest frequency and the highest frequency in the communication band of the microwave amplifier, and the second capacitor element has a reactance in which the impedance of the line, the resistor, and the second capacitor element is positioned in a vicinity of a real axis inside a circumference of a Smith chart at a maximum frequency of the beat signal generated between the lowest frequency and the highest frequency in the communication band of the microwave amplifier.