AP4420 evaluation module (under development). Image courtesy of Asahi Kasei Microdevices (AKM).
Dear students and tech community,
Imagine a warehouse with thousands of IoT sensors. Who changes all those batteries? Who runs the wiring to a sensor on a robotic arm or under a ceiling? This is one of the biggest practical barriers to scaling IoT, and it is exactly what AKM’s new chip, the AP4420, targets.
The problem: IoT doesn’t scale if power doesn’t scale
Factories and logistics warehouses are deploying more sensors for temperature and humidity monitoring, equipment condition tracking, and asset location. But every sensor needs power. Wiring is hard to install on moving parts, high places, confined spaces, and retrofits. Replacing and tracking primary batteries across hundreds or thousands of nodes is an operational headache.
The idea: power delivered over the air
Wireless Power Transfer (WPT) sends power as radio waves from a transmitter to a receiving device elsewhere in the room. Japan introduced regulatory measures for 920 MHz-band WPT systems in June 2026, covering outdoor use under certain conditions and license-exempt operation with output limits. That opens the door to more real-world deployments. (Regulations differ by country, so always check local rules.)
The catch is on the receiving side. The RF power that arrives is tiny, and it fluctuates with distance, antenna orientation, obstacles, and reflections. Turning that into stable, usable DC power is the engineering challenge.
The product: AP4420
The AP4420 is a receiver-side power management IC (PMIC) that converts small amounts of harvested RF power into DC power for IoT devices.
The technology inside
For anyone studying electronics, embedded systems, or IoT, this chip is a nice example of how several concepts combine:
- CMOS RF rectifier tuned for the 920 MHz band. It converts incoming AC radio signals into DC.
- Boost DC-DC converter. Rectified voltages from weak signals are very low, so this steps them up to a level circuits can use.
- Energy storage and power supply control. Harvested power is small and irregular, so it is accumulated and then supplied in a controlled way. This suits bursty loads such as a sensor reading followed by a Bluetooth transmission.
- Frequency flexibility. By changing the antenna and matching circuit, designers can adapt it to other bands, such as 915 MHz (North America) and 868 MHz (Europe).
It is designed to power sensors, microcontrollers, and Bluetooth Low Energy (BLE) devices. This is a good reminder that ultra-low-power design is a system-level discipline across RF, analog power, and firmware.
Where it can be used in industry
1. Warehouse environmental sensing
Sensors for temperature, humidity, door open/close status, and occupancy can be powered wirelessly and report via BLE, reducing wiring and primary batteries.
Sensors can be added to moving parts, high places, and tight spaces where cabling is impractical. The compact receiver circuit helps in space-constrained designs.
3. Beacon and asset tracking tags
Paired with a low-power BLE transmitter IC such as AKM’s AK1595B, the AP4420 enables beacon and tag designs without primary batteries, cutting the effort of managing large fleets of tags.
Why this matters for you
- Sustainability: fewer disposable batteries means less waste.
- Maintenance: less manual servicing and lower operating cost at scale.
- Design thinking: energy harvesting, low-power wireless, and edge sensing are core skills for future IoT engineers.
Discussion question for students: If a sensor only receives a few microwatts to milliwatts at varying levels, how would you design its duty cycle (sleep, sense, transmit) to keep it running reliably? Share your ideas in the comments!
#IoT #WirelessPowerTransfer #EnergyHarvesting #EmbeddedSystems #BLE #Industry40 #PowerManagement #Electronics #Sustainability #CEATEC2026