Johnson noise
Thermal Agitation of Electricity in Conductors
1/f噪声(1/f Noise)
非常重要
锁相放大器
To characterize the noise [56], the incident blackbody irradiance was blocked by a shield, whose highly reflecting surface faced the blackbody, and whose blackened surface faced the bolometer. The noise is the output voltage variation measured using the lock-in amplifier with a time constant of 30 ms.
1/f noise is present at any and low electrical frequencies, regardless of the modulation frequency of the detector. It is advantageous, therefore, to operate a detector at a frequency above the 1/f noise floor; further reduction of 1/f noise can be achieved by using an amplifier circuit with a high-pass filter to as a DC-block. There is no complete analytical derivation or description of 1/f noise, but experimental observations indicate that the mean square voltage magnitude in a 1 Hz electrical bandwidth is approximately
