Conical Wireless Charger for UAVs 🚁

: ; ; ; ;

A breakthrough conical-shaped wireless charger boosts efficiency and reliability for unmanned aerial vehicles, enabling longer missions and smarter autonomy.

Published September 21, 2025 By EngiSphere Research Editors
A Drone Landing on a Wireless Charging Pad © AI Illustration
A Drone Landing on a Wireless Charging Pad © AI Illustration

TL;DR

A conical-shaped wireless charger that doubles as UAV landing gear achieves up to 94% efficiency, solving alignment issues and enabling more autonomous drone recharging.

Breaking it Down

Why Wireless Charging for UAVs Matters

Unmanned aerial vehicles (UAVs)—or drones—are everywhere today. From delivering packages 📦, to monitoring crops 🌱, to inspecting bridges and power lines 🌉⚡, they’ve become essential tools for modern engineering and logistics.

But there’s a catch: battery life. Most drones rely on lithium-polymer (Li-Po) batteries, which typically give them only 20–60 minutes of flight time before they need to land for recharging 🔋. For missions in remote areas or during critical operations, stopping frequently for a manual battery swap is not ideal.

This is where wireless charging comes in. Imagine a drone that can land on a pad, recharge automatically, and then take off again—all without human intervention. That’s the dream of fully autonomous UAV operation, and researchers are working hard to make it a reality.

⚡ The Challenge with Existing Wireless Chargers

Wireless power transfer (WPT) works by using magnetic fields between two coils: one in the charging pad and one in the UAV. This eliminates the need for plugs or cables 🔌.

However, traditional wireless chargers face big problems:

  • Low efficiency – A lot of energy gets lost during transfer.
  • Alignment sensitivity – Flat (planar) coils need drones to land perfectly aligned, which is tough for autonomous systems. Even a small tilt or sideways landing reduces efficiency.
  • Heat buildup – High-frequency charging often leads to overheating 🌡️.
  • Extra weight – Adding separate charging hardware makes UAVs heavier, cutting flight time.

So, engineers asked: how can we design a wireless charger that’s efficient, tolerant to misalignment, and lightweight enough for UAVs?

🌀 Enter the Conical-Shaped Wireless Charger

A team of researchers proposed a fresh idea: use conical-shaped coils that double as the drone’s landing gear.

Here’s why this is brilliant:

  • Self-alignment – The cone shape naturally guides the drone into the right spot when landing, solving the misalignment problem 🤝.
  • Dual purpose – The coils are not just for charging—they are the landing gear. That means less extra weight 🏋️.
  • High efficiency – At the standard wireless charging frequency of 6.78 MHz, the system reached up to 94% power transfer efficiency in tests 🔥.

This design cleverly combines mechanical stability and electromagnetic efficiency into one solution.

🔬 How the Conical Wireless Charger Works

The system has two main parts:

1. Transmitter (Tx) Station 🛑
  • On the ground, with a conical coil and a Class EF2 amplifier (a special high-efficiency circuit).
  • Helps send power wirelessly at the ISM frequency (6.78 MHz).
2. Receiver (Rx) on the UAV 🚁

The UAV carries its own conical coil (as landing gear), plus circuits to regulate the power and charge the battery safely.

When the UAV lands, the two conical coils nest together like stacked cones. This increases coupling (how well the magnetic fields connect) and stabilizes the landing.

Think of it like a wireless handshake 🤝 between the drone and its charging pad.

📊 Simulations and Testing

The researchers didn’t just build the coils randomly—they used advanced software like Ansys Maxwell and Twin Builder to simulate how the coils would behave electromagnetically.

Key findings from their work:

  • The coupling coefficient (a measure of how well energy transfers between coils) was as high as 0.75 when perfectly aligned. Even with some misalignment, efficiency remained strong.
  • The system achieved multiple resonance peaks (frequencies where energy transfer is strong), but 6.78 MHz gave the best balance of efficiency and stability.
  • Real-life testing confirmed up to 94% efficiency—better than most previous UAV wireless chargers.

And importantly, the conical design stayed within UAV weight limits. The coils were made of hollow copper tubing to stay lightweight, with insulation for stability.

🌍 Applications of This Technology

This conical wireless charger could unlock new levels of UAV autonomy. Imagine:

  • Surveillance drones 🔍 – Patrolling continuously by recharging at multiple ground stations.
  • Delivery drones 📦 – Extending routes without human recharging.
  • Agricultural UAVs 🌱 – Monitoring fields daily without farmer intervention.
  • Disaster response drones 🚑 – Operating longer in emergency zones by self-recharging.

Basically, anywhere drones need to work long hours, this technology could make them far more useful and reliable.

🔭 Future Prospects

The study leaves room for exciting improvements:

  • Amplifier integration – The system is designed for Class EF2 amplifiers, but more real-world hardware testing is needed.
  • Thermal management – Future versions will add better cooling and thermal simulations for long-term use.
  • Adaptive frequency control – Since the system shows multiple resonance peaks, adding smart tuning could keep efficiency high under all conditions.
  • Standardization – Aligning with AirFuel/Rezence standards means it could fit into broader wireless charging networks.

In the near future, we might see autonomous UAV fleets that never need manual charging—just land, recharge, and fly again. 🌐🚁⚡

✨ Final Thoughts

This research on conical-shaped wireless chargers for UAVs represents a big step toward smarter, longer-lasting drones. By solving alignment issues, boosting efficiency, and doubling as landing gear, the design elegantly balances engineering practicality with innovative thinking.

With drones playing bigger roles in logistics, agriculture, security, and environmental monitoring, wireless charging is the missing piece for full autonomy.

Next time you see a UAV zipping by, imagine it landing gracefully on a conical charger, sipping energy like a hummingbird at a feeder 🐦⚡—and then taking off again for its next mission.


Terms to Know

UAV (Unmanned Aerial Vehicle) 🚁 A drone that flies without a human onboard, often used for delivery, surveillance, agriculture, or research. - More about this concept in the article "Sustainable 6G 📶 with Satellites, HAPS & UAVs".

Wireless Power Transfer (WPT) ⚡ A way of sending electricity without cables—using magnetic fields between coils instead of plugging in. - More about this concept in the article "Wireless Power Underwater ⚡ It's Now Rotation-Proof".

Inductive Coupling 🔄 The process of transferring energy between two coils of wire by magnetic fields—like a wireless handshake.

Power Transfer Efficiency (PTE) 📊 The percentage of power successfully sent from the charger to the drone; higher means less wasted energy.

Resonance Frequency 🎵 A “sweet spot” frequency where energy transfer is the strongest and most efficient. - More about this concept in the article "Revolutionizing Diabetes Care: The 3D-Printed Sensor Changing Glucose Monitoring 🍭 🩸".

Conical Coil 🌀 A coil shaped like a cone (think of an ice-cream cone), which in this research doubles as the drone’s landing gear.

Coupling Coefficient (k) 📐 A number (between 0 and 1) that shows how strongly two coils are linked magnetically; closer to 1 is better.

Class EF2 Amplifier 🔊 A special high-frequency electronic circuit that makes wireless power transfer more efficient and less wasteful.

AirFuel/Rezence Standard 🌍 An international guideline for wireless charging systems, ensuring compatibility and efficiency.


Source: Ali, A.; Saraereh, O.; Ware, A. Novel Design of Conical-Shaped Wireless Charger for Unmanned Aerial Vehicles. Energies 2025, 18, 5015. https://doi.org/10.3390/en18185015

From: The Hashemite University; University of South Wales.

© 2025 EngiSphere.com