A 35-GHz transmitter (TX) and receiver (RX) front-ends in CMOS technology for Ka-band frequency-modulated continuous wave (FMCW) phased-array radar transceivers is presented in this paper. In order to mitigate undesired electromagnetic coupling through LC resonators in TX/RX and avoid severe metal density issue in highly scaled CMOS technology, Ka-band RF circuit design strategy using transmission line is studied. To improve the TX output power level, a power amplifier (PA) with 4-way power spilter/combiner and transmission line for impedance transforming is introduced. The proposed TX and RX front-ends is designed and fabricated in a 65nm CMOS technology. The measured TX output power is 19 dBm. The RX achieves a conversion gain of 29.6 dB. The TX occupies 1.42 mm2 and consumes 588 mW. The RX occupies 0.59 mm2 and consumes 72mW.