The solid-state noise source integrated in the radar receiver is suggested to detect the noise figure and gain by itself. The planar solid-state noise source is designed for the receiver built-in-test, including the homemade noise diode integration, the coupler design and the drive/switch circuit design. The measure method of Excess Noise Ratio(ENR) of the noise source integrated in a receiver is presented, and the noise figure and gain can be calculated from ENR. The seamless integration with the noise source on the same substrate reduces the complexity, size and weight of the receiver. The measured and calculated results show the ENR of the noise source reaches 28 dB and satisfies the detection requirements. The detection error is acceptable. The designed circuit runs well in the environment experiments and the practical applications.