Design and implementation of L1-band C/A-code GPS RF front-end chip

This paper describes the design and implementation of an L1-band C/A-code GPS RF front-end chip. The chip incorporates a low-noise RF preamplifier, a frequency synthesizer with a conventional voltage-controlled oscillator, a variable gain amplifier, and an analog-to-digital converter. The only external requirements are a temperature compensated crystal oscillator, a two-pole LC filter, a varactor-tuned LC tank circuit for tuning the frequency of the VCO, and standard passive components for the PLL loop filter, the impedance matching and the power supply decoupling. The chip has been implemented in a 0.8-μm BiCMOS process. The chip size and operating current are 9 mm² and 42 mA at 3.3 V, respectively