A 915MHz integrated FSK receiver front-end and a CMOS ring oscillator PLL built with standard cells

This paper demonstrates a fully integrated frequency shift keying (FSK) receiver built with standard cells in .18μm CMOS without any off-chip components. Building a receiver with standard cells dictates that an inverter-based ring oscillator, rather than an LC oscillator, will be used for LO generation. This approach reduces the effort required when redesigning the receiver in a different process. Additionally, an inverter-based ring oscillator takes up much less area compared to an LC oscillator. A .18μm standard CMOS receiver prototype occupies only 500μm × 350μm of area, has a sensitivity of -76dBm at 10kbps data rate, and consumes 6mW from a single 1.8V supply while operating in 915MHz ISM band.