Patent ID: 8229987
Filing Date: 2012-07-24
Classification: H03D,H03H,H03J

Abstract:
1. A discrete time direct sampling circuit, comprising: a discrete time analog processing circuit group in which a plurality of discrete time analog processing circuits each having a first-order IIR (Infinite Impulse Response) filter characteristic are connected in parallel, each discrete time analog processing circuit comprising: a voltage-to-current converter that converts an input analog RF signal to an analog RF current signal; a sampling switch that performs sampling with a local frequency signal having a substantially same frequency as the analog RF current signal; a history capacitor, a rotation capacitor group and an integration switch group that form discrete signals temporally discretized by integrating a charge of a sampling signal; and a discharge switch group that performs on/off control of a discharge of charges from the rotation capacitor group; an output section that is provided on an output side of the discrete time analog processing circuit group, the output section comprising a buffer capacitor and a first discharge switch that performs on/off control of a connection state of the plurality of discrete time analog processing circuits connected in parallel and the buffer capacitor; and a digital controller that sends a control signal to each discrete time analog processing circuit and the output section.