Patent ID: 8391823

Claim:
A signal processing apparatus, comprising: a frequency-selective circuit, comprising: a signal input port; a first signal output port; a second signal output port; and a frequency response control block, electrically connected between the second signal output port and a signal path between the signal input port and the first signal output port, the frequency response control block arranged to control a frequency response according to a frequency of an oscillating signal; and a signal processing circuit, electrically connected to the frequency-selective circuit, wherein the signal processing circuit is arranged to deal with an input signal received by the signal input port and arranged to deal with output signals generated from the first and second signal output ports; wherein the input signal includes a first signal component with a first frequency and a second signal component with a second frequency, an offset between the first frequency and a frequency of the oscillating signal is smaller than an offset between the second frequency and the frequency of the oscillating signal, and an attenuation applied to the second signal component by the frequency response control block is greater than an attenuation applied to the first signal component by the frequency response control block.