In this paper, we present a receiver front-end and a frequency source suitable for wireless sensor network applications, in which power consumption is severely restricted under several milliwatts. For such an extremely low-power receiver current-reusing and frequency multiplying schemes are proposed for both the RF front-end and frequency source. The proposed front-end achieves a conversion gain of 30.5 dB and a noise figure of 10.2 dB at the I0-MHz intermediate frequency (IF), taking only 500-mu A bias current from a 1.0-V supply voltage. The measured phase noise of the fabricated frequency source is -115.83 dBc/Hz at 1 MHz offset from a 2.2-GHz center frequency, taking 840 mu A from a 0.7-V supply. The front-end performance is compared with the previously reported low-power front-ends operating in similar frequency ranges.