ECE 662 Microwave Electronics

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ECE 662Microwave Electronics

• Transferred Electron Devices
• February 10, 2005

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Two-Terminal Negative Resistance Devices
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Transferred Electron Device Operation (TED)
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Review of Carrier Transport
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Review of Carrier Transport
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Drift Velocity vs. Electric FieldSilicon at Room
Temperature
Ref. Sze
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Drift Velocity vs Electric Field
Ref Sze
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High Field Transport in n-type GaAs
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Negative Differential Resistance in n-type GaAs
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Measured velocity-field characteristics
Ref Sze
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Review of Carrier Transport
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Transferred Electron Device Operation (TED)
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Transferred Electron Device Operation (TED)
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Electron accumulation in the Presence of
Negative Differential Resistivity (NDR) Ref Liao
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Gunn Diode
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Eventually, the process evens out and velocities
are equal. Space charge than drifts to anode end
and the process repeats.
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Dipole Layer in Negative Differential Resistivity
(NDR) Ref Liao
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• To (d)
• Electric field vs.
• distance during
• one ac cycle at
• Four intervals, a
• to d.
• e) Voltage and
• Current wave
• Forms of a
• Transit time
• Domain mode.
• Ref. Sze

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Gunn Domain Modes
Ref Liao
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Numerical simulation of the time- dependant
behavior of cathode- nucleated TED for the
transit-time domain mode. Each successive time
is 24ps. ref. Sze
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Gunn Domain Modes
Ref Liao
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Numerical simulation of the time- dependant
behavior of cathode- nucleated TED for the
quenched domain mode. Each successive time is
24ps. ref. Sze
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Bias- dependent RF characteristics of a
D-band InP TED
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Mechanical tuning characteristic for the
D-band InP TED close to maximum bias
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Typical Structures and Doping Profiles for TED
Devices
Ref. Sze
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Solid-State Device Power Output vs Frequencyref
Sze and modifiedby Tian
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State-of-theArt RF Power Levels for TED under CW
operationref. Sze
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Summary of Transferred Electron Devices - 1 Ref
Golio (2003)

• Widely used in oscillators from the microwave
  through high mm-wave frequency bands.
• Good RF output power capability (mW to W level)
• Moderate efficiency (20)
• Excellent noise and bandwidth capability

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Summary of Transferred Electron Devices - 2 Ref
Golio (2003)

• Fabricated at low cost
• Excellent price-to-performance ratio, for
  example, most common oscillator device used in
  police automotive radars
• Many commercially available solid-state sources
  for 60 to 100 GHz (for example, automotive
  collision-avoidance radars) often use InP TEDs.