Discrete time direct sampling circuit and receiver

摘要

Provided are a direct sampling circuit and a receiver using a discrete time analog process and having a filter effect of a steep attenuation characteristic in a narrow-pass band without lowering a sampling rate. In a discrete time direct sampling circuit (13), the positive phase side and the inverse phase side are both sampled by a local signal for a differential current output of a differential voltage/current conversion unit (1011) and electric charge is accumulated in a charge sampling capacitor. The latest accumulated charge at the positive phase side and charge accumulated at the inverse phase side before a predetermined number of samples are combined with the charge accumulated in a history capacitor (1043) in the past. Thus, it is possible to realize equivalently high-degree FIR filter characteristic.