When choosing a modern wireless router in an electronics store or on a marketplace, the first thing that catches your eye is the number of antennas protruding from the casing. Consumers often mistakenly assume that the more antennas, the stronger the signal and the further it will penetrate concrete walls. However, the reality is much more complex and interesting from a radio wave physics perspective. The number of antennas is directly related not so much to range as to channel throughput and connection stability.
In this article we will analyze the technical aspects of wireless network standards 802.11n, 802.11ac And 802.11axYou'll learn why two antennas are better than one, and four are even more effective, but not in the way the marketing brochures suggest. Understanding the principles MIMO and spatial coding will help you choose the right equipment for your apartment or office without overpaying for unnecessary features.
The Range Myth and the Real Power of Radiation
The most common misconception is that adding each new antenna to a router increases its range. This isn't entirely true. Transmitter power (Tx Power) is strictly regulated by each country's legislation and is independent of the number of physical components. A router with one antenna and a router with eight antennas, operating at the same frequency and with the same factory power, will have a similar coverage range under ideal conditions.
The main goal of a multi-antenna system is not to "shout" louder, but to better "hear" the response signal from client devices. Smartphones and laptops often have less powerful transmitters than fixed access points. When a router receives a signal from multiple antennas simultaneously, it can combine the useful signal and filter out noise, improving connection quality at the limits of its range.
⚠️ Note: Increasing the number of antennas does not magically penetrate load-bearing concrete walls with rebar. Physical obstacles remain the main enemy of radio waves, regardless of the number of antennas.
In addition, the presence of multiple antennas makes it possible to implement the technology polarization diversityIf the antennas are positioned at different angles (vertically and horizontally), the router can receive a signal regardless of how you hold your smartphone. This solves the problem of connection loss when you rotate the device in your hand, which is critical for mobile devices.
MIMO Technology: The Key to High Speed
Abbreviation MIMO (Multiple Input Multiple Output) is fundamental to modern Wi-Fi standards. It involves using multiple antennas to simultaneously transmit and receive multiple data streams. Imagine a single antenna as a single-lane road where cars travel in a single queue. Multiple antennas transform this road into a multi-lane highway where traffic flows in parallel.
Equipment specifications often include designations such as 2x2, 3x3, or 4x4. The first digit indicates the number of transmitting antennas, and the second indicates the number of receiving antennas. For example, the configuration 2x2 means that the router can simultaneously send two data streams and receive two streams. This directly increases maximum speed connections.
If your router supports the Wi-Fi 5 (802.11ac) standard and has three antennas operating in 3x3 mode, the theoretical speed on an 80 MHz channel can reach 1300 Mbps. Using only one antenna (1x1 mode, often found in budget IoT devices) will drop the speed to 433 Mbps, even if the router is capable of higher speeds.
It's important to understand that for MIMO to work at its full potential, supporting hardware must also be present on the client side. If you're connecting a modern laptop with a module Wi-Fi 6 to an old router with one antenna, the connection will be established at the maximum speed available to the router, but multi-streaming will not work.
Spatial coding and reflection control
In urban environments and indoors, a radio signal rarely travels in a straight line. It bounces off walls, furniture, mirrors, and household appliances, creating multiple copies of the signal that arrive at the receiver with varying delays. This phenomenon is called multipath propagationIn older systems, this resulted in interference and loss of data packets.
Multi-antenna systems use these reflections to their advantage. Using spatial coding algorithms, the router can distinguish between the direct signal and the reflected copies, combining them into a single information stream. This improves signal-to-noise ratio and allows maintaining stable communication even in difficult electromagnetic environments.
Technology Beamforming Beamforming also relies on the presence of multiple antennas. The router analyzes the location of the client device and, using a phased approach, adjusts the signal from each antenna so that they reinforce each other in the direction of the receiver. This doesn't create a narrow beam like a laser, but it does create a zone of increased signal concentration.
How does Beamforming work in practice?
The router sends special test packets (NDP - Null Data Packets). The client device analyzes them and sends back a report. Based on this report, the router calculates a weighting matrix for each antenna to focus the signal energy toward the client.
It's worth noting that the effectiveness of Beamforming depends on the compatibility of devices. There are standards Explicit Beamforming And Implicit BeamformingIf your router uses implicit beamforming and your smartphone doesn't understand it, there will be no effect. However, compatibility has been improved in Wi-Fi 5 and later.
Separation of the 2.4 GHz and 5 GHz frequency ranges
Modern dual-band routers often have an odd number of antennas or their combinations, which is due to the need to service two frequency ranges simultaneously. Range 2.4 GHz has better penetration ability, but is heavily polluted by neighboring networks and household appliances.
Range 5 GHz Provides high speeds and has more available channels, but has poorer wall penetration. Router antennas are often divided into groups: some operate at low frequencies, others at high frequencies. For example, in a router with three antennas, two might operate in 2x2 mode at 5 GHz, while one might serve 2.4 GHz.
The presence of dedicated antennas for each range allows for the implementation of a full-fledged Dual-Band or even Tri-Band Operating mode. In tri-band models (one 2.4 GHz and two 5 GHz), the number of antennas can reach 6-8 to ensure independent operation of all radio modules without loss of performance.
| Characteristic | 2.4 GHz band | 5 GHz band |
|---|---|---|
| Penetration ability | High (better through walls) | Low (fades strongly) |
| Maximum speed | Up to 600 Mbps (theoretical) | Up to 6900+ Mbps (Wi-Fi 6E) |
| Workload | Very high (microwaves, Bluetooth) | Moderate |
| Range of action | Big | Smaller |
When setting up a router, it's important to properly distribute the load. For a smart home, where devices transmit little data but need to be online at all times, 2.4 GHz is ideal. For 4K video streaming and online gaming, 5 GHz is critical, along with multiple antennas to ensure a stable MIMO stream.
The Impact of Antenna Design on Performance
Not all antennas are created equal. External antennas, which can be rotated and replaced, typically have a higher gain than internal ones. However, internal antennas soldered to the board are often better matched to a specific Wi-Fi module, resulting in improved stability. Budget models often reduce the number of antennas, using only one external one and hiding the rest inside the case.
The antenna gain is measured in dBiA high-gain antenna (e.g., 9 dBi) has a narrower beam pattern. If your router has these antennas, the signal will travel further, but the coverage "spot" above and below the router may be poorer. Multiple antennas help expand this spot.
⚠️ Warning: Replacing the standard antennas with more powerful ones (with a higher dBi value) can lead to overheating of the router's Wi-Fi module and its failure, since the resistance and SWR (standing wave ratio) may not match the calculated ones.
Antenna placement is also important. If all antennas on the router and client are positioned parallel to each other, and the signal polarization changes due to reflections, connection quality will degrade. Therefore, manufacturers recommend positioning antennas at different angles, for example, one vertically, one horizontally, or in a fan-shaped pattern.
Comparison of Wi-Fi standards and the number of streams
The evolution of Wi-Fi standards is directly related to the increase in the number of supported streams. If in the era 802.11n (Wi-Fi 4) the de facto standard has become 2 or 3 antennas, then 802.11ac (Wi-Fi 5) brought the widespread adoption of 4 and 8 antennas. The new standard 802.11ax (Wi-Fi 6) has optimized the performance of these antennas by implementing MU-MIMO technology.
MU-MIMO Multi-User MIMO (MIMO) allows a router to communicate with multiple devices simultaneously by using different antennas for different clients. A router with four antennas can simultaneously transmit data to four smartphones with one antenna each, or to two laptops with two antennas. This dramatically reduces latency (ping) in a busy network.
The table below compares the maximum number of spatial streams in different standards:
- 📶 Wi-Fi 4 (802.11n): up to 4 streams (maximum 600 Mbps).
- 🚀 Wi-Fi 5 (802.11ac): up to 8 streams (maximum ~6.9 Gbps).
- ⚡ Wi-Fi 6 (802.11ax): up to 8 streams (max ~9.6 Gbps) with improved efficiency.
- 🌐 Wi-Fi 7 (802.11be): up to 16 streams (maximum ~46 Gbps) and MLO support.
Purchasing a router with extra antennas makes sense if you plan to use your network for several years. Devices supporting Wi-Fi 6 and 7 are becoming more affordable, and they can unlock the full potential of the multi-antenna system you install now.
How to choose a router based on antennas
Practical tips for installation and configuration
Proper physical installation of a router with multiple antennas can improve internet speed by 20-30%. The main rule is to avoid hiding the router in closed metal enclosures or behind a TV. Metal shields the signal, negating the benefits of a multi-antenna system.
If you have a two-story house, the antennas should be positioned so that the antenna pattern covers both floors. Sometimes it's helpful to point one antenna horizontally to ensure the signal spreads better laterally, rather than just downwards. Experiment with the angle, testing the speed using a smartphone app at different points in the apartment.
⚠️ Note: Router settings interfaces are constantly being updated. Menu item locationsWireless Settings,AdvancedorProfessionalmay differ depending on the firmware version and brand (Asus, TP-Link, Keenetic, Mikrotik).
In the software settings, make sure the antenna modes are not limited. Sometimes, to save power or ensure compatibility with older devices, users accidentally enable only one antenna mode. Check that the channel width is set to 20/40/80 MHz (auto) to maximize bandwidth usage.
Frequently Asked Questions (FAQ)
Is it possible to unscrew extra antennas if they are in the way?
Technically, it is possible to unscrew the antenna if it has a standard connector (usually RP-SMA). However, this strongly not recommendedThe remaining antenna will be overloaded, and the router's Wi-Fi module could burn out due to the high SWR (standing wave ratio), as some of the signal will be reflected back to the transmitter. Furthermore, you'll lose MIMO support, and the speed will drop significantly.
Does antenna length affect signal strength?
Yes, the antenna's length is directly related to the wavelength of the frequency it operates on. For the 2.4 GHz band, the optimal length is about 31 mm (a quarter wavelength), but router antennas use an inductive coil inside a plastic housing, so the external length may vary. Extending the antenna yourself with wire will worsen signal due to impedance mismatch.
Do the antennas need to be pointed directly at the device?
No, and it's often even harmful. Router antennas have a donut-shaped (toroidal) radiation pattern. The signal is weakest along the antenna axis (top and bottom). It's better to orient the antennas so their axis is perpendicular to the line connecting the router and the client, or use a fan-shaped pattern.
Does MIMO work if the client only has one antenna?
Yes, MIMO technology works in this case, but not to its full potential. The router will use its antennas to receive the signal (Receive Diversity), which will improve connection quality and range. However, data transmission (Tx) will only be in a single stream (SISO), so the maximum speed will be limited by the capabilities of the client device.
Is it true that 8 antennas make a router hotter?
The mere presence of eight antennas doesn't cause the router to heat up. Heating depends on the power of the radio modules and the processor. However, routers with eight antennas are usually flagship models with powerful hardware that requires proper cooling. If such a router is installed in a closed enclosure, it may throttle (reduce performance) due to overheating.