A 24GHz Pulse-Mode Transmitter for Short-Range Car Radar

A pulse-mode transmitter with low carrier leakage for 24 GHz short-range car radar applications is described. A 12.5 dBm output power amplifier (continuous into 50 Omega), a pulse width and rate control circuit and a voltage reference circuit are included on the IC. The pulse-mode 24GHz output signal is modulated via the final stage bias current to achieve a RF carrier leakage of -50 dBm in the off-state. The power dissipation is 360 mW when RF is on, 117 mW when RF is off, resulting in a typical 122 mW dissipation in normal operation. The 1.2 times 0.87 mm² IC operates from a 4.5 V supply and is fabricated in 0.25 mu m SiGe:C BiCMOS technology [1].