Microwave Radar Module for EV Charging Stations | Smart Human Detection & Auto Screen Wake-Up

Today’s featured product is the WT4101A-C01 radar module. One of its key application scenarios is human detection and automatic screen activation for electric vehicle charging stations.

Have you ever experienced this: arriving late at night at a charging station on your e-bike, only to find the screen completely dark? You fumble around trying to locate a button, staring at a “dead” display. Or in a parking lot lined with chargers, only the one you approach hasn’t lit up yet, leaving you navigating in the dark. These details may seem minor, but they directly impact user experience.

So, is there a solution that allows a charging station to act like a thoughtful gatekeeper—detecting your approach from a distance, lighting up in advance, and activating the interface so you can plug in immediately? The answer lies in a tiny microwave radar module the size of a fingernail—WayTronic’s WT4101A-C01.

What Is Microwave Radar? A Simple Analogy

Before introducing this “invisible gatekeeper,” let’s first understand how microwave radar works.

Imagine it continuously emits microwave signals forward, like repeatedly calling out: “Is anyone there?” When nothing is present, the signal dissipates with no response. But once a person approaches, their body reflects the signal back, creating an echo. By analyzing the time delay, frequency shift, and phase difference of this echo, the radar can determine that someone is present—and even estimate their distance.

The WT41 series microwave radar sensors operate in a high-frequency band, offering strong penetration, long detection range, higher resolution than low-frequency radar, and smaller antenna size. In short, they strike an optimal balance between performance and cost.

The Real Pain Point of Charging Stations: Not Functionality, but “Perception”

Returning to the charging station scenario: when WayTronic’s clients were developing next-generation EV chargers for overseas markets, they encountered a typical challenge—proximity-based screen activation.

This requirement sounds simple: when someone approaches, the screen lights up automatically. However, two key challenges arise.

1. Penetration Through Materials

Charging station screens are usually covered by a glass panel, with sensors installed behind it. Any sensing solution must “see through” this barrier.

Infrared sensors struggle here due to low glass transmittance, often causing detection failure or drift. In contrast, the WT41 series uses microwave signals that naturally penetrate acrylic, glass, and thin non-metal materials. For it, the glass panel is almost like transparent air.

2. Anti-Interference Capability

Charging stations operate in complex electromagnetic environments: motor noise, 50Hz/60Hz power frequency interference (varying by country), and surrounding Wi-Fi signals. These combined noises can easily cause false triggers in conventional sensors—lighting up when no one is present or failing to respond when someone is standing right in front.

The WT41 series integrates an onboard MCU with multiple digital filtering algorithms. It includes dedicated filters for both 50Hz and 60Hz interference, as well as algorithms to handle Wi-Fi and other wireless signals. This makes it like a professionally trained security guard, capable of identifying real “visitors” in a noisy environment.

Surprisingly Small, Impressively Powerful

You might wonder: with so many features, is the module large or power-hungry?

Let’s look at the actual specifications. The WT4101A-C01 measures only 19.5mm × 18mm × 1.6mm—roughly the size of a SIM card and thinner than two stacked coins. It fits easily behind a charging station display panel.

Power consumption is equally impressive. In default operation, the module draws just 880 μA. To put that into perspective, a standard AA battery could power it for thousands of hours. It operates within a voltage range of 2.8V to 3.5V and a temperature range of -20°C to 60°C, ensuring stable performance from cold Nordic winters to hot Middle Eastern climates.

In terms of sensing, the WT41 series offers a forward detection range of 5–8 meters, with ±0.5 meter accuracy and a 3-second output delay. As a user walks toward the charger, the screen lights up just before they reach out—delivering that subtle but satisfying “just right” experience.

One Chip, A More Human-Centric Charging Station

Stepping back, the “auto wake-up screen” feature reflects a broader challenge in smart hardware: how to make devices more proactive, intelligent, and user-friendly—using minimal cost and space.

The WT41 series provides a clear answer: no need for major redesigns or complex systems. Just a compact module placed behind the screen gives the charging station a pair of “invisible eyes.” It works regardless of day or night, weather conditions, or surrounding signal noise—focusing solely on detecting your presence and lighting the way.

This is the unique appeal of microwave radar technology: silent yet always active, invisible yet perceptive. In future smart cities, such “invisible gatekeepers” will become increasingly common—not only in charging stations, but also in elevators, streetlights, access control systems, and vending machines. And it all begins with a tiny module like this one.