Table 1.
Summary of literature on adaptive transcutaneous systems.
| Goal | Tuning | Feedback | Variation | |||
|---|---|---|---|---|---|---|
| Tx | Rx | Tx | Rx | |||
| [77] | Min reflections | Frequency (VCO) | Reflected voltage | Resonant frequency | ||
| [78] | Max efficiency | Frequency (VCO) | Antenna voltage | Resonant frequency | ||
| [40] | Max received voltage | Frequency (VCO), Power (supply voltage) | Rectified voltage | Resonant frequency, coupling | ||
| Max driver efficiency | Amplifier (transductor) | Phase between LC and coil driver voltage | Impedance due to frequency change | |||
| [82] | Resonance | Impedance (varactor) | Reflected voltage phase change | Distance and impedance | ||
| [83] | Resonance | Impedance (duty-cycled C) | Frequency | Impedance | ||
| [39] | Stable received power | Power (supply voltage) | Rectified voltage | |||
| [13] | Stable received power | Impedance (duty-cycled C) | Rectified voltage | |||
| [36] | Stable received power | Power (supply voltage) | Storage capacitor voltage | Movement and load impedance | ||
| [73] | Max efficiency | Frequency | Resonator voltage | Coupling, impedance | ||
| [80] | PA optimal load | Matching impedance (simulated) | Antenna impedance | Impedance | ||
| [31,89,93] | Match to PA or LNA | Matching impedance (varactor, switched C bank) | Antenna impedance | Impedance | ||
| Matching impedance (varactor) | Antenna impedance | Impedance | ||||
| [14,41] | Max power transfer efficiency | Power (supply voltage) | Rectified voltage | Position, fibrous tissue growth | ||
| Impedance | Rectified voltage | |||||
| [64,71,81,90] | Max power transfer efficiency | Matching impedance (switched C bank) | Rectified voltage | Position, impedance | ||
| Matching impedance (switched C bank) | Rectified voltage | |||||
| [37] | Stable received power | Power (supply voltage) | Rectified voltage | Distance, alignment | ||
| [79] | Max received voltage | Impedance (switched C bank) | Rectified voltage | Position | ||
| Stable received power | Power (supply voltage) | Rectified voltage | Position | |||
| [72] | Max efficiency (optimum load) | Impedance (switched C bank) | Rectified voltage gradient | Load impedance | ||
| [34] | Stable received power | Frequency (ZVS) | Switch transistor drain voltage | Coupling, load impedance | ||
| [15] | Max efficiency (relative to absorption) | Field pattern (antenna feeds) | Rectified voltage | Position | ||
| [92] | Max power transfer | Impedance (switched CLC pi bank) | Antenna port voltage | Impedance | ||
| [43] | Max power transfer | Frequency (ZVS) | Resonant tank voltage | Coupling | ||
| [84] | Max efficiency | Impedance (variable C) | S-parameters | Coupling | ||
| [23] | Max power transfer | Matching impedance (variable C) | S-parameters | Coupling | ||
| Max efficiency | Power | Reflected voltage | Coupling | |||
| [12] | Stable power, max efficiency | Power, resonant frequency | Received power | Coupling | ||
| [94] | Resonance | Impedance (switched C) | Output voltage, tuning capacitor voltage | Resonant frequency | ||