1 Revenue

　　Both high-frequency circuits and low-frequency power supply circuits have voltage gain and output power harvesting effects. Resonant differential amplification circuit refers to the resonant frequency f0, and for fiber broadband differential amplification circuit, it refers to a frequency range.

　　2-way band

　　The concept difference with low-frequency power circuit boards is good. For resonant differential amplification circuits, most of them are the values between the two corresponding frequencies when the normalized vibration amplitude of the pointer decreases to 0.707 for the resonant frequency f0; For fiber optic broadband amplification circuits, it refers to the corresponding meaning relative to a certain frequency.

　　3. Selectivity

　　Selectivity mainly targets resonant amplification circuits, which characterize the circuit's ability to select useful signals and suppress useless signals. Usually, the rectangular coefficient and suppression ratio are measured based on the resonant characteristic curve of the circuit.

　　4 Noise coefficient

　　When amplifying a circuit, due to certain factors, fluctuations will move irregularly, creating noise inside the circuit, which can affect the quality of the signal. This effect is usually described by the ratio of signal power PS to noise power PN (SNR). The coefficient of noise is the comparison between input signal noise and output signal noise.

　　5 Stability

　　The stability of a high-frequency circuit board refers to the stability of its main performance when the working state or working conditions change. For example, when the temperature of the environment changes or the voltage of the power supply fluctuates, it will affect the normal operation of the amplified circuit DC; The parameters of circuit components will also change accordingly, which will lead to changes in the gain of the amplification circuit, frequency transfer of the center, and sudden changes in the resonance curve. Ultimately, it may result in a fundamental inability to function properly.