In this letter, we proposed a highly linear mixer-first receiver with a discrete-step attenuator (DSA) and a noise-shaping TIA. A resistor-reuse technique is devoted to improving linearity and attenuation flatness of the DSA with frequency independance, and a negative impedance chopping method is proposed to reduce the in-band noise of the TIA. Measurement results show that the receiver achieves >13dBm IIP3 and in-band noise floor has been depressed by 4dB, with only consuming 2.82mW under 1.3V supply.