What is a WiFi Antenna? WiFi Stick Antenna & Built-in Antenna Function

A Wi-Fi antenna is a component of a Wi-Fi device (like a router or adapter) that transmits and receives radio waves carrying data. These waves allow devices to connect to a wireless network, enabling internet access. Antennas can be either external (like a stick or a panel) or built-in within a device.

I. Basic principles and functions
WiFi antennas are core components of wireless communication systems. Their core function is to achieve the mutual conversion between electrical signals and electromagnetic waves, which directly affects the transmission distance, signal stability and anti-interference ability. This principle is based on the propagation law of electromagnetic waves described by Maxwell’s equations, and optimizes signal transmission efficiency through polarization (such as vertical/horizontal polarization).

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50*9mm High performance 3dBi 2.4G WIFI Built-in PCB antenna RF1.13 cable IPEX/U.FL port

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II. Classification and structural characteristics
‌Built-in antenna‌
Mainly used in mobile devices such as mobile phones and laptops, it can be divided into standard type (such as magnetic dielectric antenna) and non-standard type. Among them, standard antennas need to rely on process optimization (such as LTCC technology) due to bandwidth and volume limitations.
‌External antenna‌
Commonly found in wireless routers, it uses a sleeve rod design or a magnetic base to enhance signal reception. Par exemple, the ASUS TUF BE9400 router is equipped with 6 external antennas, supporting three bands (2.4GHz/5GHz/6GHz) and WiFi 7’s MLO multi-link operation technology.
Types of Wi-Fi Antennas:
Omnidirectional Antennas:
These antennas broadcast signals in all directions, providing wide coverage within a specific area.

Directional Antennas:
These antennas focus signals in one specific direction, suitable for longer range or point-to-point connections.
USB WiFi Antennas: These antennas connect to a computer’s USB port and provide wireless connectivity. They can be used to improve signal strength or range, especially in areas with poor WiFi reception.
Built-in Antennas: Many devices, including laptops, smartphones, and some routers, have antennas integrated into their design.

Function of Wi-Fi Antennas:
Transmitting:
Wi-Fi antennas convert digital data into radio waves and send them to other devices.
Receiving:
Antennas also capture radio waves from other devices, convert them back into digital data, and make the data available to the connected device.

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III. Core performance parameters ‌Gain and Directivity‌: High-gain directional antennas (such as CPE) are suitable for long-distance coverage, while omnidirectional antennas are suitable for multi-angle transmission; however, an increase in the number of antennas may introduce coupling interference, and it is necessary to balance gain and layout rationality.
‌Band compatibility‌: The frequency bands (such as 2.4G/5G/6GHz) and connector types (such as SMA, TNC) supported by the device must be matched.
‌Polarization mode‌: The combination of vertical and horizontal polarization can reduce signal attenuation and improve wall penetration.

IV. Evolution of multi-antenna technology
‌Beamforming‌
By coherently superimposing multi-antenna signals, the signal strength is enhanced in a specific direction (such as increasing the 3dB array gain), but the incoherent loss caused by delay differences must be avoided.
‌Multi-band phased array technology‌
The multi-band antenna solution proposed by Huawei’s patent supports 5G, WiFi and Bluetooth, and can dynamically adapt to different communication standards to improve device compatibility.

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2.4GHz 5GHz Dual Band WiFi Wireless Router Bluetooth Antenna

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V. Design Practice Suggestions
‌Antenna Layout‌: It is recommended that external antennas be distributed at an angle of 45°~90°, taking into account both omnidirectional coverage and directional enhancement.
‌Quantity and Coupling Control‌: The number of router antennas needs to be optimized according to the aperture area to avoid blind stacking and performance degradation.

Through the above technological evolution, WiFi antennas are developing in the direction of high frequency bands, low latency, and adaptive multi-scenario. Par exemple, the tri-band support of ASUS WiFi 7 routers and Huawei’s multi-standard fusion design are typical representatives.