A V-Band Transmitter Front-End IC for Phased-Array FMCW Radar with Impedance-Invariant Variable-Gain Phase Shifter

초록

This paper presents a V-band transmitter front-end (TXFE) IC for phased-array frequency-modulated continuous wave (FMCW) radar, which includes a variable-gain phase shifter and medium-output power amplifier (PA). For accurate phase and gain control, the phase shifter employs an impedance-invariant technique by combining two vectors which one is always 90° ahead than the other. Therefore, variation of the current flowing each I and Q amplifier in vector generator are compensated during phase and gain control. The PA comprises four stages with three cascode pre-amplifiers featuring cross-coupled capacitors. The proposed TXFE IC was fabricated in 65-nm bulk CMOS process with a core size of 0.81 mm2. The measured RMS phase error of 6-bit phase resolution was 2.15°, and the RMS gain error of 5-bit gain states for a 16-dB dynamic range was 0.43 dB at 58.5 GHz. The measured peak gain and Psat were 28 dB and 11.9 dBm, respectively, at 58.5 GHz and 60 GHz.

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