1. 1 IMS2015 TH2E-1 Active Power Summation for Efficient Multiband RF Energy Harvesting Aaron N. Parks Joshua R. Smith University of Washington TH2E-1

2. 2 IMS2015 TH2E-1 wisp5.wikispaces.com

3. 3 IMS2015 POWER LIMITED and VOLTAGE LIMITED RF-harvesting systems are: Stored charge Power consumption Active TH2E-1

4. 4 IMS2015 Harvester sensitivity => Range TH2E-1

5. 5 IMS2015 TH2E-1 TV Tower 1 MW @ 539 MHz Harvester

6. 6 IMS2015 Multiband harvesting topology TH2E-1

7. 7 IMS2015 Detail: One band Bandpass filter isolates one band from others Per-band matching networks Per-band rectifiers TH2E-1

8. 8 IMS2015 Divide and conquer TH2E-1 Single band S11 frequency Multiband S11

9. 9 IMS2015 Summation of band output power TH2E-1 Simple serial connection = Increased V OUT

10. 10 IMS2015 Unexcited bands are dead weight TH2E-1 Simple serial connection = Increased V OUT

11. 11 IMS2015 Single tier bypass network TH2E-1 Single Bypass Diode Simple serial connection Shortcut current path

12. 12 IMS2015 Full diode bypass network TH2E-1 Simple serial connection Full diode network Shortcut current path

13. 13 IMS2015 Intelligent switching network TH2E-1 Simple serial connection Bypass switching SC 5 SC 4 SC 3 SC 2 SC 1 V SUM OPEN CLOSED V SUM CLOSED OPEN

14. 14 IMS2015 TH2E-1 OPEN CLOSED V SUM CLOSED OPEN

15. 15 IMS2015 Cold start behavior TH2E-1 Time V OUT Cold startOptimization Active V ON OPEN CLOSED V SUM CLOSED OPEN

16. 16 IMS2015 Comparing summation methods TH2E-1 SC 5 SC 4 SC 3 SC 2 SC 1

17. 17 IMS2015 R LOAD = 100kΩ, P IN = -10dBm (100µW) TH2E-1

18. 18 IMS2015 TH2E-1 R LOAD = 100kΩ, P IN = -20dBm (10µW)

19. 19 IMS2015 Maybe next year: Dynamically self-tunable “agile” harvesting? TH2E-1

20. 20 IMS2015 Thanks! Questions? Aaron N. Parks Joshua R. Smith sensor.cs.washington.edu TH2E-1