This paper presents the Ka-band RF front-end for the frequency channelization receiver. The main blocks of the RF front-end are the low-noise amplifier(LNA), on-chip passive Balun, down-conversion mixer and output buffer. To achieve broad bandwidth at Ka-band frequency, stagger tuned load and series peaking technique are employed. The prototype receiver front-end was designed in 45nm CMOS technology. The prototype circuit achieves >15dB conversion gain, 5dB NF and >-15dBm IIP3 with 87.6mW power consumption and 0.42mm(2) active area.