A 45 W Bias Power, 34 dB Gain Reflection Amplifier Exploiting the - - PowerPoint PPT Presentation

A 45 μW Bias Power, 34 dB Gain Reflection Amplifier Exploiting the Tunneling Effect for RFID Applications

Francesco Amato, Christopher W. Peterson, Brian D. Degnan, Gregory D. Durgin School of Electrical and Computer Engineering Georgia Institute of Technology

Reflection amplifiers

Reflection amplifiers are active devices that, when opportunity biased, display a negative resistance (-R).

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1 2

M = 0.25 M = 1 M > 1

Power consumption

Kimionis2014 Chan2013 Chan2011 Lazaro2013 Cantu2008 Cantu2006 Dalman72

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0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45

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0.1 0.2 0.3 0.4 0.5 0.6 Tunnel Diode IV curve V [V] I [mA]

Tunnel Diode IV curve I [mA] V [V]

Quantum tunneling

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The design

Aeroflex Metelics MBD5057-E28 Tunnel diode equivalent circuit

The design

Schematic Microstrip model

Reflection Amplifier Characterization (1/2)

• How does it behave at different input frequencies?
• What happens to amplitude and phase of the reflected RF signals?

Vector Analyzer

• VNA E5071B
• Avg on 16 traces
• RF Pin = -50 dBm

Reflection Amplifier Characterization (1/2)

Vector Analyzer

• Optimum bias voltage: 80 mV
• Measured current: 566 μA
• Pbias = 45.28 μW

Reflection Amplifier Characterization (1/2)

Vector Analyzer

• Optimum bias voltage: 90 mV
• Measured current: 525 μA
• Pbias = 47.25 μW

Reflection Amplifier Characterization (1/2)

Vector Analyzer

• Δφ1 = 45˚
• Δφ2 = 53˚

Reflection Amplifier Characterization (2/2)

• At what RF input power levels is the gain available?
• What is the bandwidth of the reflection amplifier?
• How does the gain change with bias voltages?

Signal Generator Reflection Amplifier Signal Analyzer

• Sig. Gen. E8247C
• Sig. An. CXA-N9000A
• Res BW: 3 kHz
• Video BW: 100 kHz
• Span: 1 MHz
• Avg: 10
• Points: 1001

Attenuators

Signal Generator Reflection Amplifier Signal Analyzer

Reflection Amplifier Characterization (2/2)

• Used bias powers: 45 μW and 47 μW
• Max gains: 34.4 dB and 22.1 dB
• Input frequencies: 5.45 GHz, 5.55 GHz

Signal Generator Reflection Amplifier Signal Analyzer

Reflection Amplifier Characterization (2/2)

• Used bias voltages: 80 and 90 mV
• Input powers: -70 dBm and -60 dBm

Signal Generator Reflection Amplifier Signal Analyzer

Reflection Amplifier Characterization (2/2)

• Input frequencies: 5.45 GHz and 5.55 GHz
• Input powers: -70 dBm and -60 dBm

5.7997 5.7998 5.7999 5.8 5.8001 5.8002 5.8003

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Frequency [GHz] Pout [dBm]

Backscattering from semi passive tag Backscattering from reflection amplifier with tunnel diode

Modulated spectrum

Modulation with 250 kHz square wave 35.6 dB gain Input RF power: -60 dBm

Conclusions

• High reflection gains achieved with

low power consumptions

• Working with RF input powers

as low as -90 dBm

Chan2013 Chan2011 Lazaro2013 Cantu2008 Cantu2006 Dalman72 Kimionis2014

Thank you f.amato@gatech.edu

5.7997 5.7998 5.7999 5.8 5.8001 5.8002 5.8003

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Frequency [GHz] Pout [dBm]

Backscattering from semi passive tag Backscattering from reflection amplifier with tunnel diode

Backscatter Modulation

Power consumption

Degenerate Semiconductors

I V

Semiconductors heavily doped with donors (n-type) have the Fermi level up inside the conduction band Semiconductors heavily doped with acceptors (p-type), have the Fermi level inside the valence band When a p-n junction is formed, a thin junction region is created as result of keeping the continuity of the Fermi level This results in a finite probability that electrons

• vercome the energy barrier when a small

biasing voltage is applied (quantum tunneling [3])

Tunnel Diode

Semiconductors

Energy band diagram, diode

I V