A 24-GHz Fully Integrated CMOS Transceiver for FMCW Radar Applications

A 24-GHz fully integrated frequency-modulated continuous wave (FMCW) direct conversion transceiver, implemented in a 55-nm low-power CMOS technology with a maximum f $_{T}$ of 190 GHz in typical operating conditions and packaged in a 5-mm x 5-mm 32-lead quad-flat no-leads (QFN) package, is presented in this article. The single-chip transceiver uses a single 2.5-V supply while all the core circuits are powered by integrated regulators. The complex low-noise transductor in the receiver uses a quadrature hybrid to generate quadrature signals in the receiving front-end. The analog signal processing circuits including high-pass filters, low-pass filters, and programmable amplifiers are implemented following the receiver front-end circuitry. The FMCW signals are generated by an on-chip 24-GHz fractional-N frequency synthesizer. The synthesizer is completely integrated with the transceiver and provides built-in digital frequency modulation to generate chirping signals for the down-conversion local oscillator (LO) and the transmitted signals. The transmitter is composed of a balanced class-AB power amplifier driven by the FMCW signals from the frequency synthesizer.