A CMOS low-power receiving signal strength indicator using weak-inversion limiting amplifiers

Receiving signal strength indicator (RSSI) has been widely used in wireless receiver communication systems such as wireless local personal networks (e.g. Bluetooth), wireless local area networks (e.g. WLAN 802.11a, b, g, j, n), cellular networks (e.g. GSM, UMTS), digital broadcasting (e.g. DAB, DVB-TH), and positioning systems (e.g. GPS) [1-3]. The RSSI is normally employed to represent the received signal power strength. It can also be used to adjust the gains of the RF front-end, analog baseband, and power down the receiver when there is no signal.