Background: Backscatter radio is
extensively used for radio frequency identification (RFID), sensing, and
localization. The increased number of pervasive
internet of things (IoT) systems that utilize backscatter radio as a
low-power and low-cost communication scheme has led to dense deployments
of tags that need to operate under bandwidth constraints. However,
typical backscatter radio modulators perform switching "on-off"
operation and modulate data with rectangular pulses, which occupy an
extensively wide bandwidth.
Technology: Inventors John Kimionis and Manos
Tentzeris have developed techniques and an apparatus regarding RF
front-ends that control the tag reflection coefficient over time in a
continuous manner, thus enabling the generation of arbitrary
backscattered waveforms and reduced bandwidth occupancy. Compared to
repetitive lobes in rectangular pulses, square
root raised cosine (SRRC) and other arbitrary waveforms feature a
main-lobe bandwidth in the spectrum occupancy. These waveforms are
generated using complex backscatter modulation schemes by exploiting
continuous variation of the antenna load, instead of switching between
two discrete values. While maintaining low RF front-end complexity, PIN
transistor (FET), or any other non-linear element with
voltage-controlled variable impedance are used to variate the antenna
load. The techniques developed are practical for integration with low
computational ability devices (e.g. microcontrollers) and allow wireless
backscatter communication with high-order and faster data-rate
Potential Commercial Applications:
Benefits / Advantages:
Enables the same form of low-power communication mechanism via reflection instead of radiation
Smaller bandwidth occupancy, thus increasing number of devices being able to communicate in a portion of the spectrum.
Denser tag/node/sensor/transponder deployments while still adhering to FCC regulations can be achieved
- Generation of more complex/higher datarate modulation schemes with a single non-linear component than just binary modulation, which is the typical case for RFID/backscatter tags.
John Kimionis– Graduate student – Georgia Tech School of Electrical and Computer Engineering
Manos M. Tentzeris – Professor – Georgia Tech School of Electrical and Computer Engineering