A Four-Channel CMOS Front-End for Interference-Robust GNSS Receiver

A four-channel receiver front-end is designed and implemented for interference- and jamming-robust global navigation satellite system (GNSS) in a 0.18-mu m CMOS technology. The front-end consists of four identical RF-to-IF signal paths including low-noise amplifiers (LNAs), mixers and IF amplifiers. In addition, it also includes a phase-locked loop (PLL), which synthesizes the local oscillator (LO) signal, and a serial peripheral interface (SPI) for parameter adjustment. To improve the interference and jamming robustness, a novel linearity improvement technology and LO duty cycle adjustment method are applied in LNA and mixer design, respectively. The receiver achieves a gain of 40 dB, an input-referred third-order intercept point (IIP3) of -8 dBm and a jammer-to-signal power ratio (JSR) of 72 dB under 1.8-V and 3.3-V supply, while occupying a 4 x 5 mm(2) die area including the electrostatic discharge (ESD) I/O pads.