Narrowband Transmitters: Ultralow-Power Design

Abstract

WSNsTo come up with a general WSN link budget, consider a representative WSN system operating with a carrier frequency of 2.4 GHz at a communication distance of 10 m. Most WSN nodes operate in peer-to-peer ad hoc networks, where each node can potentially act as a relay between other nodes. Consequently, WSN transceivers must balance power specifications evenly between the

Low-Power Wireless Transceiver With 67-nW Differential Pulse-Position Modulation Transmitter

“…Increasing f B B may, however, be beneficial if the output power is scaled up by an equal factor to maintain the SNR and uplink range. Transmitter architectures generally consume most power in LO generation and power amplification [1]. Moreover, the carrier generation typically dominates the power budget in ultra-low power transmitters [8].…”

“…In this case using a high f B B and increased output power enables a lower EPB and is favorable. Here we did not consider the fact that the achieved PA efficiencies are generally higher at higher output powers [1] which could improve the EPB of TX2 even further. Nevertheless, increasing f B B can only be exploited limitedly as bandwidths are in practice regulated by local authorities and a wideband spectrum may violate such standards [1].…”

“…For low P R F , such transmitter architectures can be utilized that minimize the number of high-power blocks. One option is a direct-modulation architecture where the major blocks are a carrier synthesizer, a modulator, and a PA [1], [5]. Another option is a direct-RF power oscillator (PO) topology that consists of two major blocks: a modulator and a PO [1], [3], [6].…”

“…One option is a direct-modulation architecture where the major blocks are a carrier synthesizer, a modulator, and a PA [1], [5]. Another option is a direct-RF power oscillator (PO) topology that consists of two major blocks: a modulator and a PO [1], [3], [6]. These architectures have been popular in published sub-mW narrowband transmitters and have enabled low EPBs.…”

“…The power consumption of the devices should therefore be minimized. In wireless devices, and particularly sensor nodes [1], a significant amount of power can be consumed by radios. Thus, transmitter and receiver solutions with minimal power consumption have been sought.…”