RF Coil Power Management with Charge Pump and Periodic Charging
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Solution Overview
Problem
Conventional electronic devices, such as non-contact IC cards and sensor network devices, face inefficiencies in power usage due to unnecessary power consumption in standby states and limited operational areas due to reliance on RF coils and external power sources, leading to low energy use efficiency.
Innovation Solution
The electronic device incorporates an RF coil for electromagnetic wave reception, a step-up circuit with a diode and capacitor for power conversion, a charging and discharging circuit with a second capacitor for power storage and control, and an RF transmission circuit using a charge pump type circuit, which reduces standby power consumption and allows for efficient power transmission even with low generated voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If an RF coil is used to receive electromagnetic waves and generate power, then the device can operate without a battery, but standby power consumption is not reduced to zero
Solution Approach 1:
The charging and discharging circuit periodically charges the capacitor when RF power is received and discharges it when RF power is not received, avoiding continuous power consumption in standby state. This periodic operation allows the device to consume zero power when not actively receiving or transmitting signals.
Solution Approach 2:
The device uses its own RF coil to both receive power and transmit signals, eliminating the need for separate power reception and signal transmission systems. This self-service approach reduces overall power consumption while maintaining full functionality.
2Power
If the size of the RF coil is increased to receive more power at one time, then power reception capability is improved, but the total effective area of the electronic device increases
Solution Approach 1:
The charge pump circuit converts voltage in the vertical dimension rather than increasing coil area in the horizontal dimension. By stepping up voltage from the small RF coil, the system achieves high power capability without increasing the physical footprint of the device.
Solution Approach 2:
The system changes the voltage parameter through the charge pump circuit to achieve higher power output from a small RF coil, rather than relying on increased coil size. This parameter transformation allows high power reception with minimal device area.
3Power
If an RF amplifier is used to amplify received power, then power transmission capability is improved, but unnecessary power is consumed
Solution Approach 1:
The RF coil serves dual purposes: receiving power and transmitting signals. This eliminates the need for separate RF amplifiers, reducing power consumption while maintaining transmission capability through the charge pump's voltage boosting function.
4Ease of operation
If a battery or external power source is used instead of an RF coil, then independent operation is achieved, but power is consumed even in standby state
Solution Approach 1:
The device operates periodically by charging the capacitor when RF power is available and discharging it when RF power is unavailable. This periodic operation enables independent functionality while consuming zero power in standby states, unlike continuous battery operation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration minimizes standby power consumption to zero, reduces the size of the RF coil, and decreases transmitted power, enhancing overall energy use efficiency while reducing noise and operational limitations.
Implementation Method 1
an RF coil for receiving an electromagnetic wave and converting the electromagnetic wave into power
Implementation Method 2
a diode 406 and a capacitor 407 which are used for converting alternating current (AC) of the RF coil 401 into a direct current (DC)
Implementation Method 3
a charge pump type circuit operated by a capacitor is used as the step-up circuit
Data Source
AI summary
A Provided is an electronic device in which: alternating current power from an RF coil which receives an electromagnetic wave and converts the electromagnetic wave into power is rectified by a diode and a first capacitor; the power is stepped up by a charge pump type step-up circuit; the power stepped up by the step-up circuit is stored in a second capacitor by a charging and discharging circuit; and the stored power is supplied from the charging and discharging circuit to an RF transmission circuit.