Abstract: Based on the application of the active phased array radar, this paper presents a low-immediate frequency(IF) receiver in S band with four channels and 2.2~2.5 GHz radio frequency(RF) input and 2~6 MHz IF.The receiver features a high integration to improve the T/R modules cost and weight properties, consisting of four channels and local path(LO) and digital control modules. In order to compensate for crosstalk among four channels, multiple layout techniques are introduced. The circuit was fabricated based on the SMIC 0.13 μm CMOS process, occupying a die area of 3.91 mm×3.66 mm. The experimental results show that the gain adjustment range of four-channel low-IF receiver achieves ≤9.25 dB NF, the dynamic gain is above 58.29 dB and the channel isolation is above 32.2 dB.