Analog Devices has released the new ADF4158 PLL synthesiser which enables flexible implementation of FMCW (frequency modulated continuous wave) radar systems. FMCW radar systems are used widely in automotive, aerospace, military, industrial and communications applications to remotely measure the relative distance and speed of external objects. FMCW radar systems can deliver detection and ranging at much lower power levels compared to traditional pulsed radar approaches, thereby offering a significant cost advantage.

FMCW radar systems require very high radio performance and current approaches that rely on the linearity of the VCO (voltage controlled oscillator) pose a number of design challenges due to their complexity, inflexibility and high cost. The latest addition to ADI’s family of PLL synthesisers, the ADF4158, is a 6,1 GHz programmable device that can be configured to suit individual FMCW radar system designers’ needs.

Implementation of an FMCW radar system using the ADF4158 produces a highly linear ramp profile that is completely independent of VCO linearity, thereby improving radar resolution and reducing cost and complexity associated with system calibration. The device’s 25-bit modulus allows sub-Hertz frequency resolution, together with frequency and phase modulation capability. It is capable of generating saw-tooth and triangular waveforms in the frequency domain, a parabolic ramp, a ramp with frequency-shift keying (FSK) superimposed or a ramp with two different sweep rates.