How a Wi-Fi router's signal travels: from the antenna to your device

Have you ever wondered why the Wi-Fi signal in one room is excellent, while in another it's barely even a one? Or why your laptop in the kitchen connects without a problem, while your smartphone in the bedroom stubbornly loses connection? The answer lies in the physics of radio wave propagation—the very signal your router emits 24 hours a day. This article isn't about abstract "magic rays," but rather about the very specific laws that govern it. The Wi-Fi signal interacts with the space of your home.

We'll look at how 2.4 GHz differs from 5 GHz in terms of wall penetration, why metal cabinets are the worst enemies of a stable connection, and what is multipath propagation (and why it's both your internet's friend and enemy). You'll also learn how Even the arrangement of furniture can dramatically change the coverage area., and why sometimes it's enough to simply turn the router the other way for the signal to suddenly "break through" to where it wasn't before.

No, it’s not magic – it’s radio physics, and all routers, from budget ones, obey it. TP-Link TL-WR840N to the flagship ASUS RT-AX88UUnderstanding these processes will help you not only place your router correctly but also choose the right settings for your home.

1. How a Wi-Fi signal works: Basics of radio physics

Wi-Fi signal is a type electromagnetic waves, which travel through space at the speed of light. Your router converts digital data (your internet requests, YouTube videos, instant messages) into radio waves of a specific frequency, and devices (smartphones, laptops, smart speakers) capture these waves and convert them back into data.

Key signal characteristics that influence its propagation:

• 📡 Frequency: 2.4 GHz or 5 GHz (and in newer standards, also 6 GHz). The higher the frequency, the more data can be transmitted per second, but the less well the waves bend around obstacles.
• 📶 Transmission power: Measured in milliwatts (mW) or decibels (dBm). In most countries, the maximum permitted power for Wi-Fi is 100 mW (20 dBm), but many routers operate at 50-70 mW.
• 🌀 PolarizationWaves can be vertically or horizontally polarized. This affects how the signal is reflected from surfaces.
• 🔄 Modulation: A method of "packing" data into a signal (e.g. QAM-256 Wi-Fi 6 allows you to transfer more data in the same amount of time).

It is important to understand that the Wi-Fi signal does not spread evenly in all directions, like light from a light bulb. Its intensity depends on:

• 📌 Router Antenna Designs (Are Two Antennas Always Better Than One?)
• 🏠 The materials from which the walls and furniture in your home are made
• 📱 The sensitivity of your device's receiver (at iPhone 15 Pro it's higher than that of a budget smartphone)
• 🌐 The presence of other radio sources (neighboring Wi-Fi networks, microwave ovens, cordless phones)

⚠️ Attention: If your router supports Wi-Fi 6E (6 GHz), remember that this range has an even shorter wavelength, meaning it penetrates obstacles even worse. It should only be used in line-of-sight conditions or for devices in the same room as the router.

2. 2.4 GHz vs. 5 GHz: Which Band Penetrates Walls Better?

This is the most common question when setting up dual-band routers. The answer is simple: 2.4 GHz penetrates obstacles better, but 5 GHz provides higher speeds and less interference from neighbors. Why is that?

In practice this means:

• 🏢 In an apartment building with thick concrete walls 2.4 GHz is often the only working option for distant rooms.
• 🏡 In a private house or studio apartment with minimal obstacles 5 GHz will provide a more stable and faster connection.
• 📱 Modern smartphones (for example, Samsung Galaxy S23 or iPhone 14) can automatically switch between ranges, but they don't always do it optimally.

There is also a compromise option: Mesh systems (For example, TP-Link Deco or Google Nest Wi-Fi) automatically select the best range for each device and can "pass" it between network nodes. However, this is a solution for larger homes, not a standard two-bedroom apartment.

3. Obstacles in the signal path: what blocks Wi-Fi the most?

If you think the main problem is the distance from the router, you're wrong. Signal quality is much more significantly impacted by the materials it passes throughHere's a list of your Wi-Fi "enemies," ranked from worst to best:

1. Metal (Refrigerators, cabinets, reinforced walls, mirrors with a metal coating) – almost completely shield the signal. Even a thin sheet of metal can attenuate the signal by 30-50%.
2. Concrete and brick — weaken the signal by 10-25% per wall. They are especially bad monolithic concrete slabs in panel houses.
3. Glass with a metallized coating (energy saving windows) - can block up to 40% of the signal.
4. Wood and plasterboard — weaken the signal minimally (5-10%), but thick wooden doors or furniture can result in a noticeable deterioration.
5. Water (Aquariums, pipes, even the human body) absorb radio waves. Therefore, the signal in the bathroom is often weaker than in other rooms.

Interesting fact: furniture arrangement The signal also plays a role. For example, if there's a metal-framed sofa or a mirrored cabinet between you and the router, the signal will be weakened more than if there was a wooden cabinet in the same spot.

And here's what does not affect on Wi-Fi as much as is commonly thought:

• 🌿 Houseplants (unless it's a whole greenhouse)
• 🧸 Stuffed toys, clothes, books
• 🖼 Pictures on the walls (if they don't have metal elements)

4. Multipath propagation: why does the signal "jump" around the room?

If the Wi-Fi signal only traveled in a straight line from the router to the device, the internet would be very poor in most homes. Fortunately (and unfortunately), this is what actually happens. multipath propagation (multipath propagation). This means that:

• 🔄 The signal not only goes directly, but also reflected from walls, ceiling, floor, furniture.
• 📶 Your device receives more than one signal, several copies of it, who came by different routes.
• ⏱ These copies may come with with different delays, which leads to interference (superposition of waves).

There are two types of interference:

• 🟢 Constructive - when waves add up, strengthening the signal (you suddenly get excellent reception in an unexpected place).
• 🔴 Destructive — when the waves cancel each other out, creating “dead zones” (you move your laptop 30 cm and the internet disappears).

That's why sometimes it's enough just rotate the router the other side or slightly change the angle of the antennas so that the signal "breaks through" to where it previously wasn't. And in some cases, even move half a meter to the left/right - this is how you get out of the zone of destructive interference.

Modern routers with support MU-MIMO (For example, Netgear Nighthawk AX12>) and Beamforming Directional beamforming (DBB) attempts to combat this problem by focusing the signal on specific devices. But even this cannot completely eliminate the multipath effect—a fundamental property of radio waves.

Why does the signal appear and disappear in some places?

This happens because you're located at the edge of the interference zone. Even a slight movement (such as standing or sitting) can alter the phase of the reflected waves, causing the signal to be either amplified or attenuated. This effect is especially noticeable at 5 GHz due to its short wavelength.

5. How antenna shape and placement affect coverage

If you think that router antennas simply "scatter" the signal in all directions, then you are missing half the truth. Shape, number and orientation of antennas radically change the coverage area. Here's what you need to know:

Types of antennas in routers:

• 📶 External removable (on most budget models, for example, Tenda AC10) - allow you to change the tilt angle, but often have a low gain (2-5 dBi).
• 🔄 Internal (in compact routers like Xiaomi Mi Router 4A) - less flexible in configuration, but protected from physical damage.
• 📡 Directed (in some Mesh systems or point routers) - focus the signal in one direction, increasing the range but narrowing the coverage area.

How to properly orient antennas:

• 🔼 Vertically — the signal is distributed preferentially in the horizontal plane (good for one-story houses).
• 🔽 Horizontally - the signal spreads better vertically (useful for two-story apartments).
• 🔄 At an angle of 45° — a compromise option for covering both horizontally and vertically.

If your router two antennasDon't place them parallel to each other—this will result in a loss of coverage. The best option is:

• 📌 One antenna is vertical, the second is horizontal (for coverage in both width and height).
• 📌 Or both at an angle of 45°, but in different planes (for example, one forward-up, the second forward-down).

⚠️ Attention: If you are using a router with external antennas If you notice that the signal has worsened after relocating the antenna, check to see if the connectors have become loose. Sometimes, simply tightening the antenna a little is enough to restore the connection.

6. Practical tips: how to improve coverage without buying a new router

Before you run out to the store for a repeater or mesh system, try these free or cheap Ways to improve the signal:

Move the router to the center of the apartment | Rotate the antennas at a different angle | Remove metal objects from the signal path | Change the channel in the router settings (especially to 2.4 GHz) | Update the router firmware -->

Optimal router placement:

• 🏠 Please install it if possible in the center of the apartment, and not in the corner by the window.
• 🪟 Avoid placing near metal objects (refrigerator, metal cabinets, mirrors).
• 🌿 Don't hide your router in a closet or behind a TV - The plastic case also weakens the signal.
• ⚡ If possible, connect the router to the network via Powerline adapter (For example, TP-Link AV1000) to move it to a better location without laying cables.

Router settings worth checking:

• 🔄 Wi-Fi channel: On 2.4 GHz, choose the least loaded one (use apps like Wi-Fi Analyzer for Android).
• 📶 Transmission power: In some routers it can be increased manually (look for the parameter Transmit Power in the settings).
• 🔒 Opening hours: If you have older devices, set the mode 802.11n instead of 802.11ac/ax - This can improve stability.
• 🔄 Channel width: On 2.4 GHz, it is better to leave 20 MHz (not 40) to reduce interference.

If nothing helps, consider budget-friendly ways to boost signal:

• 🛠 Homemade reflector from a beer can or foil (yes, it works, but it doesn’t look very nice).
• 🔌 Wi-Fi repeater (from 1000 rubles, for example, TP-Link RE305).
• 📡 Replacing antennas to more powerful ones (for example, from 3 dBi to 9 dBi, but remember that this may violate the router certification).

7. Wi-Fi Myths: What Doesn't Actually Work

The internet is full of "advice" that not only doesn't help, but can actually make things worse. Let's address the most common myths:

❌ Myth 1: "The more antennas, the better the signal."

In fact: The number of antennas affects throughput (due to MIMO technology), but not on rangeA router with four antennas won't have a greater range than one with two—it will simply be able to simultaneously exchange data with more devices.

Myth 2: "If you place the router higher, the signal will be better."

Actually: Altitude helps if you live in two-story house and want to cover both floors. In a standard apartment, placing the router on a cabinet often degrades the signal at floor level (where most devices are located), since radio waves travel not only sideways but also downwards.

❌ Myth 3: "40 MHz mode on 2.4 GHz gives higher speed"

In fact: In a densely populated house, a channel width of 40 MHz will result in increased interference from neighbors and may even reduce the actual speed. Optimally, leave it at 20 MHz.

Myth 4: "Disabling DHCP will speed up Wi-Fi."

In fact: DHCP is responsible for distribution of IP addresses, and disabling it doesn't affect signal speed or range. However, it may create problems connecting new devices.

❌ Myth 5: "Wi-Fi 6 automatically solves all coverage problems"

In fact: Wi-Fi 6 (802.11ax) improves throughput and work with multiple devices, but does not increase rangeIf you're having coverage issues, what you need isn't a new standard, but rather proper router placement or repeaters.

⚠️ Attention: Some "Wi-Fi optimizers" for smartphones promise to "boost the signal by 2 times." In reality, they simply force the device to connect to the router at maximum power, which can reduce battery life and does not provide any real speed increase.

FAQ: Frequently asked questions about Wi-Fi signal propagation

❓ Why does Wi-Fi work well in one room and not in another, even though the distance is the same?

This is related to multipath propagation And interferenceThe signal can be reflected off walls and furniture, creating zones of amplification or attenuation. Materials also play a role: for example, if there are walls between rooms metal door or wall with reinforcement, the signal will be weakened further.

Solution: Try change the location of the router or rotate the antennas from a different angle.

❓ Is it true that a microwave interferes with Wi-Fi?

Yes, but only if it works. Microwave ovens use frequency. 2.45 GHz, which falls within the 2.4 GHz Wi-Fi range. This creates strong interference, especially if the router is located near the kitchen.

Solution: Use 5 GHz for critical devices or move the router away from the microwave.

❓ Which router penetrates walls better: with external or internal antennas?

It doesn't depend on the type of antennas, but on their gain (measured in dBi). External antennas often have gain 5-9 dBi, while internal ones are usually 2-3 dBi. However, removable antennas allow you to experiment with their orientation, which can be useful in difficult conditions.

Examples of routers with good coverage: Keenetic Ultra (external antennas, 5 dBi), ASUS RT-AX58U (internal, but with good signal optimization).

❓ Can weather affect Wi-Fi?

In normal home conditions - NoWi-Fi operates on frequencies that are not affected by weather. However, in rare cases severe thunderstorm may create electromagnetic interference that affects the stability of the connection.

But here's what really makes a difference: humidity indoors (for example, after renovation or in a bathroom), since water absorbs radio waves.

❓ Why does Wi-Fi work faster at night?

This is not related to signal propagation, but to channel congestionAt night, most neighbors are asleep, and their devices don't create interference. Also, some providers unload the network at night, increasing the speed for subscribers.

If the difference between day and night is significant, this is a sign that your channel overloaded — you should change it in the router settings.