A Ka-band 4TX/4RX dual-stream joint radar-communication phased-array transceiver is presented for the emerging radar-communication integrated wireless system. Different from the existing joint radar-communication transceiver with separated downconversion path and analog baseband, the proposed joint radar-communication transceiver features completely reused hardware components. In addition, various circuit design challenges in the joint radar-communication transceiver are addressed. In order to enhance the signal-to-noise and distortion ratio (SNDR) in low input power region for the communication mode and effectively reduce the chip area, a current-flopping bidirectional active mixer is proposed. A variable-transmission-line-based phase shifter (TL-PS) with tiling structure is introduced to achieve wideband phase shifting with flat group delay and in-band loss fluctuation. A pseudo-stacked power amplifier (PA) is introduced to provide both high linearity and high saturated output power for the joint radar-communication transceiver. A 4TX/4RX dual-stream joint transceiver is designed and fabricated in a standard 65-nm complementary metal–oxide–semiconductor (CMOS) process with the chip area of 16.2 mm2. The measured results show that the TRX covers 28.7–36.2 GHz with the peak gain of 22.2/34.7 dB for TX/RX. The measured TX peak saturated output power is 19.9 dBm and the OP 1dB is 17.4 dBm. The measured RX minimum noisefigure (NF) is 4.8 dB and the IP 1dB is >?31.5 dBm. In addition, the analog baseband offers a 3.5-GHz bandwidth for the wideband radarsignal. System measurement indicates that the proposed transceiver supports real-time centimeter-level 2-D imaging and 400-Msym/s 64-quadrature amplitude modulation (QAM) over-the-air (OTA) wireless link.