摘要
A K-band ultra-wideband (UWB) pulse-compression (PC) automotive radar transmitter in 90-nm CMOS is presented, which is composed of the fully integrated pulse generator, mixer, driver amplifier, phase-locked loop, and timing circuitry. The PC technique with coding gain can effectively enhance the detection resolution and also improve the signal-to-noise ratio (SNR). We propose a PC transmitter allowing fast and precise code generation with small power consumption and chip area, and also offering reconfigurable capability. Compared with previously reported UWB pulse radars with relatively simple coding schemes, the proposed transmitter features a much more challenging 15-bit pseudonoise code design using high-speed shift registers, which can improve SNR up to 23.5 dB. The measured results demonstrate correct output waveforms corresponding to different modulation codes with the spectrum well confined under the regulation mask. With a modulation rate over 3 Gb/s (pulse repeat frequency of 6.125 MHz), a resolution of ∼ 5 cm can be achieved.