Signal-to-Noise Ratio Measurements for IoT Communications with - PowerPoint PPT Presentation

Signal-to-Noise Ratio Measurements for IoT Communications with Quantum Tunneling Reflectors Francesco Amato December 13 th 2016 f.amato@gatech.edu School of Electrical and Computer Engineering Georgia Institute of Technology 1

Movement detection E-health Ambient Sensing and monitoring Connected cars Smart cities …. Overview: IoT applications |Background | Experimental Setup | Results | Long Range Measurements 2

Use photos (BLE, RFID applications) RFID BLE + Simple RF front-end + Ubiquitous + Low power consumption + Longer communication ranges - Short communication ranges - Higher power consumption - Complex RF front-end Idea: developing quantum tunneling-based RFIDs to achieve long ranges with low power consumption Overview: BLE & RFID|Background | Experimental Setup | Results | Long Range Measurements 3

Quantum Tunneling RFID Tag RF in DC block modulated RF out RF choke DC bias tunnel diode Microcontroller Reflection Ampl ifier Power Power f m f c f c f us f ls Frequency Frequency a) b) Overview: quantum tag |Background | Experimental Setup | Results | Long Range Measurements 4

Reflection amplifiers > 1 M = 0.25 M = 1 M > 1 Reflection amplifiers are active devices that, when opportunity biased, display a negative resistance (-R). Overview |Background: reflection amplifiers | Experimental Setup | Results| Long Range Measurements 5

Quantum Tunneling Reflection Amplifier Bias Tee C 1 V Bias Tuning stub RF in Tunnel Diode Overview |Background: reflection amplifiers | Experimental Setup | Results| Long Range Measurements 6

• Reflection amplifiers are based on injection locking effect • The non-linearity of tunnel diodes can affect the Signal to Noise ratio (SNR) • In a quantum tunneling reflector, the SNR depends on weather or not it locks at the external frequency Once locked, the SNR depends on: - The biasing voltage V DC - The external RF signal strength P in - The modulation speed f m - The presence of undesired input signals acting as interferers Overview |Background: reflection amplifiers | Experimental Setup | Results| Long Range Measurements 7

Experimental Setup Bias Tee C 1 V B ia s Tuning stub RF i n Tunnel Diode Overview |Background | Experimental Setup | Results | Long Range Measurements 8

Oscillations Overview |Background | Experimental Setup | Results: oscillations | Long Range Measurements 9

Injection locking -30 -40 -50 P out (dBm) -60 -70 -80 V DC = 60.0 mV, no RF input -90 5.785 5.79 5.795 5.8 5.805 5.81 5.815 Frequency (GHz) Overview |Background | Experimental Setup | Results: locking | Long Range Measurements 10

Injection locking Overview |Background | Experimental Setup | Results: locking | Long Range Measurements 11

Injection locking Overview |Background | Experimental Setup | Results: locking | Long Range Measurements 12

Signal-to-Noise Ratios Overview |Background | Experimental Setup | Results: SNR | Long Range Measurements 13

The locking range Overview |Background | Experimental Setup | Results: locking range | Long Range Measurements 14

The locking range Power and Energy: V DC = 60 mV, I DC = 340 uA Power: 20.4 uW, Energy: 2.9 pJ/bit @ 7 MHz Overview |Background | Experimental Setup | Results: locking range | Long Range Measurements 15

Interferers Overview |Background | Experimental Setup | Results: interferers | Long Range Measurements 16

Interferers Overview |Background | Experimental Setup | Results: interferers | Long Range Measurements 17

5.8 GHz RFID Transceiver and Tag Overview |Background | Experimental Setup | Experimental Results | Long Range Measurements 18

Overview |Background | Experimental Setup | Experimental Results | Long Range Measurements 19

Overview |Background | Experimental Setup | Experimental Results | Long Range Measurements 20

Thank you Bias Tee Demodulator C 1 RF in V Bias Charge Pump or Battery Tuning stub DC block RF in modulated RF out RF choke DC bias Tunnel Diode unnel t diode Microcontroller Reflection A mpl ifier P o w er P o w er f m f c f ls f c f u s Frequ ency Frequ ency a) b) 21

Signal-to-Noise Ratio Measurements for IoT Communications with Quantum Tunneling Reflectors Francesco Amato December 13 th 2016 f.amato@gatech.edu School of Electrical and Computer Engineering Georgia Institute of Technology 22