2.4-GHz receiver for sensor applications

This paper describes a receiver designed to meet the stringent power consumption requirements for sensor radio, which operates at 2.4-GHz ISM band with Bluetooth. To enable the reusability of the Bluetooth system, only slight changes are made in the radio parameters. The symbol rate is decreased and the increased modulation index removes the energy maximum from the channel center, which enables a low-complexity direct-conversion receiver solution. To meet the speed and power requirements, this receiver is fabricated in a 0.13-μm CMOS process. The 3.4-mW direct-conversion demonstrator receiver includes a low-noise amplifier, which is merged with quadrature mixers, local oscillator buffers, and one analog baseband channel with a 1-bit limiter for analog-to-digital conversion. The receiver consumes 2.75 mA from a 1.2-V supply. The receiver achieves 47-dB voltage gain, 28-dB NF, -21-dBm IIP3, and +18-dBm IIP2.