Function and Selection of 4G LTE Antennas

Functions and production of 4G LTE antennas

I. Core functions of 4G LTE antennas
‌Signal reception and conversion‌
Antennas, as converters of electromagnetic waves and electrical signals, realize data interaction between base stations and terminals. They must meet the requirements of frequency matching (such as LTE FDD band B1/B3) and polarization mode (mainly vertical polarization), and the standing wave ratio (VSWR) ≤ 2.0 to reduce impedance mismatch loss.

‌MIMO technology enhances capacity‌
Spatial multiplexing is achieved through multiple input multiple output (MIMO) technology. A typical 4×4 MIMO configuration can increase edge area throughput by 30%-50%, supporting a peak rate of 300Mbps (80MHz bandwidth).
The antenna array adopts a cross-polarization design, combined with precoding (such as SVD decomposition) to optimize the beamforming effect.

‌Diversity anti-interference‌
Diversity technology (MRC, SC) receives signals through multiple antennas to combat multipath fading and industrial environment interference, and improve link stability.

‌Directional coverage optimization‌
The directional antenna achieves 6-18dBi gain through a microstrip patch array, with adjustable beam width (30°-90° horizontally, 7°-15° vertically), suitable for directional coverage scenarios such as tunnels and underground garages.

Signal Transmission and Reception:
LTE antennas convert electrical signals into electromagnetic waves to transmit data and receive incoming signals from base stations.

MIMO (Multiple Input Multiple Output):
LTE utilizes MIMO technology, using multiple antennas to transmit and receive data simultaneously, increasing data rates and improving the robustness of wireless links.

Beamforming:
This technique directs radio waves in a specific direction, enhancing signal strength and reducing interference, especially in base stations.

Carrier Aggregation:
LTE supports carrier aggregation, combining multiple frequency bands to increase bandwidth and data rates, requiring antennas capable of handling wider frequency ranges.

Diversity Approaches:
LTE employs diversity techniques, using multiple antennas with different polarizations or locations to improve signal robustness and reduce interference.

II. Key Indicators and Strategies for Selection
‌Frequency Band Compatibility‌
It needs to cover the mainstream frequency band of 700-2700MHz, and specific scenarios need to support dual-band or multi-mode (such as Cat.1bis single antenna solution for wearable devices).

‌Gain and scene adaptation‌
‌Weak signal area‌: Select a high-gain directional antenna of more than 12dBi, and match it with a relay node to expand coverage;
‌Dense urban area‌: Omnidirectional antenna (3-5dBi) optimizes 360° coverage, with a horizontal beam width of 65°-120°.

‌Protection level and interface‌
Outdoor deployment requires IP67 protection level, and industrial scenarios prefer SMA/N-type interfaces, supporting waterproof connectors and cable extension.

‌Antenna type selection‌
‌Omnidirectional antenna‌: 60° uniform radiation, gain 3-5dBi for urban base stations and smart home coverage.
‌MIMO array antenna‌: 4×4 multi-channel, supporting spatial diversity and multiplexing for high-speed mobile communications and industrial Internet of Things.
‌Wideband suction cup antenna‌: 700-6000MHz coverage, magnetic base for quick installation for vehicle-mounted communications and remote monitoring.

‌Protocol Adaptation‌
Select compatible protocols according to device type:
‌Cat.1bis/NB-IoT‌: low-power narrowband scenarios (such as water meters, smart street lights);
‌LTE-M‌: medium-speed mobile devices (such as wearable devices).

III. Typical application scenarios and deployment solutions
‌Weak signal area enhancement‌
Use external high-gain directional antennas (such as 18dBi logarithmic periodic antennas), deploy relay nodes to achieve signal relay, and combine MIMO 2×2 diversity reception.

‌High-speed mobile scenarios‌
In-vehicle communications need to support dynamic beam tracking and antenna switching (Handover), compensate for Doppler shift, and adapt to scenarios such as high-speed rail and drones.

‌Industrial Internet of Things‌
Wideband antennas (700-2700MHz) are connected to PLC controllers, redundant antennas are configured to improve reliability, and antenna cascading expands coverage.

‌Base station expansion‌
Mechanical antenna downtilt adjustment (optimal 1°-5°) to avoid signal distortion; directional antennas are used in dense urban areas to reduce co-channel interference.

IV. Technology Evolution Direction
‌Millimeter wave integration‌: miniaturization of high-frequency band antennas to support 5G NR enhanced mobile broadband (eMBB);
‌Intelligent beamforming‌: AI algorithm optimizes antenna array phase in real time to improve spectrum efficiency in multi-user scenarios.

The selection needs to integrate frequency band, gain, environment and protocol requirements, and modular design is prioritized to adapt to future upgrades.