PORTLAND, Ore. Energy harvesting radio technology targeted for future Mars missions could make use of a single-chip microtransceiver being developed at Kansas State University.
The device uses a silicon-on-sapphire CMOS process from Peregrine Semiconductor Corp. (San Diego) that was developed with NASA funding. The low-power integrated RF functions of the CMOS transceiver can operate in the harsh Martian environment. Commercial applications include using energy harvesting to power radios for remote wireless sensors.
The single-chip microtransceiver operates in the 390-450 MHz band with 100mW output, said Kansas State engineering professor William Kuhn. "We are now building on that work for energy harvesting and other applications."
So far, university researchers have demonstrated that a solar-powered radio can operate in the extreme cold of Mars without the heaters currently used on two Mars Rovers. The Martian atmosphere is very thin, allowing damaging radiation to reach the surface. Surface temperatures range from minus 76 to minus 184 F, making Peregrine's radiation-hardened silicon-on-sapphire technology the only CMOS process capable of operating on the Martian surface without a heater.'
Kansas State researchers are now working with Peregrine to repurpose the RF chip technology for energy-harvesting applications on Earth. "Our development work has produced proof-of-concept hardware for using our single-chip radio in energy harvesting applications," said Kuhn. "We have also done research on what frequencies of operation may be most useful."
The researchers hope to use frequencies freed up by the transition to digital TV. "We have done research on propagation distances for low-power 10-milliwatt transmitters from VHF [151 MHz] through the more popular, but worse-performing, 2.4-GHz band," Kuhn added.
The RF chip includes an integrated transmitter and superheterodyne receiver with an off-chip IF filter. Data from a Mars Rover will be modulated onto a 400-MHz carrier for transmission at rates as high as 256 Kbits/s. Receive data rates range from 2-8 Kbits/s.
Kansas State and Peregrine hope to commercialize the technology using several schemes that make use of the low-power RF chip, including possible stress, temperature and pressure monitoring on bridges. Sensors would be powered using either solar cells or other techniques for harvesting electrochemical, mechanical or thermal energy.