Radio Frequency Wireless Charging: How RF Charging Works?

November 3rd, 2016


While certain forms of wireless charging have been in development for over a century, other newer forms of wireless charging have proven to be the next big step towards a world where wearable and electronic devices can be charged anywhere, without chargers and tangled cords. Let’s have a look at how Radio Frequency Wireless Charging is making waves!


How Does RF Wireless Charging Work?

In order to create radio frequency wireless charging, two integral parts are needed:

1. A transmitter that transmits the RF waves.

Radio Frequency Wireless Charging

One example of a possible shape for Humavox’s NEST charging station (embedded within is the RF transmitter). The NEST transmits the RF energy within a resonant cavity to charge the device.

2. A receiver embedded within the device (not a coil) that picks up the RF energy and converts the into DC voltage.

Radio frequency wireless charging Receiver

Humavox’s small receiver, embedded within the device

Radio Frequency Wireless Charging for Dummies

Radio frequency wireless charging technology utilizes radio frequencies to charge a device. While there are several different forms of wireless charging technologies, RF wireless charging is different in that is uses electromagnetic waves, rather than induced magnetic fields (induction).

Think about your wi-fi router, and how it transmits internet to your computer, smartphone, or wearable device. RF wireless charging is somewhat similar in that it uses radio frequencies to transmit energy from a wireless charger to receiver within a similar device, that is then converted into electricity. The converted electricity then becomes the power source for your electronic device!


RF Wireless Charging Technology vs. Inductive Charging

So how is RF wireless charging DIFFERENT from induction?

Induction vs. Humavox RF Receiver

Induction coil vs. Humavox’s small RF receiver

1. Physics, my dear!

Radio frequency wireless charging differs from magnetic induction first and foremost by the physical character of each technology. Inductive charging uses an electromagnetic field generated by a coil. This coil has physical limitations in size and shape in order for effective wireless charging to take place. Meaning, it can only be integrated into large, flat devices that have the empty real-estate to integrate a coil, such as a possibly a smartphone. RF, on the other hand, has a receiver based on electronic circuitry.


RF Wireless Charging Device

Devices placed freely within the wireless charging NEST

2. User Experience

Induction wireless charging, requires transmitter and receiver for exact alignment or placement for effective charging. RF, on the other hand, is not limited by positioning for effective wireless transfer.


Benefits of RF wireless charging technology

1. Seamless integration

Unlike induction and other forms of wireless charging, RF wireless charging is not restricted by measurements, allowing it to accommodate devices that induction cannot. Because RF wireless charging does not have the same physical limitations in size and shape, the receiver can be integrated into the smallest of electronic devices, such as small wearables, hearing aids, and more. And that leads us to….


 2. Drop & Charge

With RF wireless charging technology, there is no need for precise placement as there is with plugs or inductive charging pads. This means that no matter how you place your device within a certain area, it will charge – regardless of how the device is placed.

Humavox's Wireless Charging for Hearing Aids

Another Humavox NEST form factor that provides the drop & charge experience

3. Convenience

As devices are becoming smaller and smarter, plugging everything into charge and fiddling with tiny plugs becomes a bigger hassle. Imagine an elderly person with hearing aids that need to be recharged. Having to fiddle with plugging them in every night is an incredible burden to deal with. With RF wireless charging, on can simply drop your tiny hearing aids (or smartwatch, or any device), into a cup or a bowl and…voila! Its’ charging wirelessely.

Humavox's RF Wireless Charging Station

Another example of a possible Humavox NEST Charging Station

4. Never having to fiddle with multiple cords

There are many benefits to RF wireless charging, but the main one is never having to deal with multiple cords! Think about all of the electronic devices you need to plug in each day, and how many different cords, chargers and electricity sockets this requires. Now imagine that you can charge all of your devices and gadgets easily, and in one convenient place! Wireless charging eliminates the need for the mess by just letting you drop your devices into one charging station, without having to fiddle with thousands of different cords.Importance of Wireless Power

Read more:

Be prepared to be surprised: Surprising uses of wireless charging in everyday life

Don’t miss: The dark side of wearable technology

Glimpse into the future: 3 ways wireless charging will improve our life in the future


Are there different forms of RF wireless charging technology?

YES! Different companies have created a different take on RF wireless charging. The main two categories


1. Far-Field RF Wireless Charging Technology

Far-field RF wireless charging is the emission of RF in free space. Here the concept is to have a transmitter (similar to a wifi router) that can locate an RF receiver in a defined area and as long as the device is located in that area it’ll charge. Far-field RF wireless charging, however, is limited in its charging capability given that a great amount of energy is lost in free space.


2. Near-Field RF Wireless Charging Technology

Humavox is currently the only company that does near-field RF charging. We built our technology with the vision of blending wireless charging into life by allowing any 3D volume to become a charging station (transmitter). It could be a cup holder, a drawer, or even a box- all the places that are most intuitive for users to simply place their device.

radio frequency wireless charging

Humavox’s ETERNA utilizes near-field RF to ensure effective Rx and Tx coupling, effectively optimizing the charging profile and controlling the charging process.

The near-field RF wireless charging technology allows for full charging from 0-100% given and provides users with a “drop & charge” experience. Meaning, users can simply drop their devices in a charging station and regardless of placement, it’ll charge!

Humavox’s RF Wireless Charging Technology

At Humavox, we have created a new way for RF wireless charging that lets users simply drop their wearable into a charging station, blending wireless power into all your different life environments.

Our wireless charging technology platform, ETERNA, is flexible enough that it enables designers to integrate wireless charging into nearly any object. Our power transmitter, NEST, can be a case, bowl, or any other object naturally integrated into our lives that might be used as a charging station. In addition, Thunderlink is a tiny wireless charging receiver module that can be implemented into the smallest of electronic devices (such as hearing aids, smartwatches, and more), in order to make wireless charging convenient for all.

Where Can You Find Humavox’s RF Wireless Charging Technology?

Humavox is currently working to integrate our wireless charging technology with several different original equipment manufacturers (OEM’s) in various sectors from the wearable and IoT sectors. This includes fitness, consumer, healthcare, enterprise, and more!  For example, we’ve recently announced a new partnership with Starkey Hearing Aids, one of the world’s leading hearing aid manufacturers, in order to implement wireless charging into their hearing aid devices.

RF Wireless Charging Technology for Hearing Aids

Starkey hearing aids with Humavox’s wireless charging technology


The Future of RF Wireless Charging Technology

In a world where everything is connected, having all of your devices and electronics be ‘smart’ is our new way of life. As these devices are becoming smarter, they are also getting smaller and more mobile.  This means more small and compact devices being integrated into our everyday habits – at work, at home, in the medical world and more. Having to deal with the mess of wires and constantly plugging in cords is simply not an option. That is why wireless charging is the only natural solution to our IoT and device-infused future.

At Humavox, we have created a new way for RF wireless charging that allows designers to customize, adjust, and incorporate wireless charging into nearly any wearable of any shape and size. By letting users simply drop their device into a charging station, we are blending wireless power into each and every type of different wearable for any type of environment.

Soon we will all charge without even noticing!