Low-power Integrated Transmitter Design Using Frequency Multiplication Techniques

This paper proposes an approach to employ frequency multiplication techniques like edge-combining and third harmonic extraction in ultra-low-power integrated transmitter design. The overall power demand of the transmitter is reduced by keeping operating frequency of its components low. For that reason, edge-combining and third harmonic extraction are integrated directly into a switched mode power amplifier. Hence, the radio frequency signal is generated just before it is fed to the antenna. This leads to a reduced power demand of the overall transmitter in comparison to conventional designs where the oscillator and other components are operated directly at the radio frequency. Within this paper we propose an amplifier that generates a 2.4 GHz carrier frequency from a ring oscillator running at a low 200 MHz resulting in a frequency multiplication factor of twelve. The exemplary design is targeted to be used in ultra-low-power short range applications. Hence, our simulations using extracted layout models show that the amplifier provides an output power of approximately -12 dBm at a supply voltage of 0.6 V while consuming 2.4 mW of power fully integrated in a 180 nm 1P6M CMOS process. This demonstrates that the proposed techniques are especially suitable for ultra-low-power transmitter in short range applications. That includes medical and body area network applications.