I. Core Technical Parameters and 5G Base Station Adaptation Characteristics

　　Frequency Coverage Range

　　It shall match the mainstream 5G operating frequency bands. Among them, the sub-6GHz band (3.3-5.0GHz) is the primary frequency band for current macro base stations, requiring full-band coverage by low VSWR splitters; products for the millimeter-wave band (24-40GHz) are designed for high-density urban micro base stations and need to meet wide-band low-reflection requirements. Some high-end models support multi-band compatibility (1.8GHz-40GHz) to adapt to the 5G network deployment needs of different operators.

　　Core Indicator of Low Voltage Standing Wave Ratio (VSWR)

　　5G base stations have strict requirements for signal reflection control. The VSWR in the sub-6GHz band shall be ≤1.2:1, and due to faster signal attenuation in the millimeter-wave band, the VSWR shall be controlled within ≤1.3:1, with a fluctuation deviation of no more than ±0.05 across the entire frequency band. This indicator shall be achieved through high-precision impedance matching design to avoid reduced base station reception sensitivity and increased interference caused by signal reflection.

　　Supplementary Key Performance Indicators

　　In terms of insertion loss, it shall be ≤15dB (including the theoretical distribution loss of 12dB) in the sub-6GHz band; due to higher transmission loss in the millimeter-wave band, the insertion loss shall be ≤16dB. The isolation shall be ≥22dB to prevent signal crosstalk between multiple ports from affecting the beamforming accuracy of Massive MIMO (massive antenna system). The power capacity shall match the output of the base station Radio Remote Unit (RRU): splitters for macro base stations support 50-100W continuous power, while those for micro base stations only need to support 20-50W.

　　Structure and Interface Specifications

　　Interfaces are mostly of SMA-J or 4.3-10 type: the former is suitable for medium and low-power scenarios, while the latter, with lower contact impedance (≤0.1Ω), is more suitable for high-power and low-reflection requirements. The shell is mostly made of integrated die-cast aluminum alloy; some models for outdoor deployment adopt IP65 waterproof rating design with built-in heat dissipation channels, adapting to the operating temperature range of -40℃~+65℃ to meet the installation environment of outdoor base station cabinets or tower tops.

　　II. Core Technologies for Achieving Low VSWR

　　Transmission Line Impedance Matching Design

　　High-precision CNC machining technology is used to manufacture microstrip lines or coaxial transmission structures, with impedance tolerance controlled within ±0.5Ω, ensuring precise matching with the 5G base station RF link (characteristic impedance of 50Ω). Some products introduce compensation capacitors or inductors to correct impedance deviations at the edge of the frequency band (e.g., 3.3GHz, 5.0GHz), further reducing the VSWR.

　　Cavity Structure Optimization

　　The traditional spliced cavity is abandoned, and an integrated die-casting process is adopted to reduce signal reflection points at the cavity joints. The inner cavity coating uses high-conductivity materials (such as brass with gold plating, silver plating) to reduce conductor loss and reflection coefficient during signal transmission, while improving corrosion resistance and extending the outdoor service life.

　　Port Contact Design

　　The inner conductor of the port is made of beryllium copper, which has excellent elasticity and conductivity, ensuring stable contact pressure (2-3N) during plugging and unplugging and reducing contact impedance fluctuation. Some models add a choke coil structure at the port to suppress parasitic signals in the high-frequency band, avoiding an increase in overall VSWR caused by port reflection.

　　III. Core Selection Points

　　Priority of Frequency Band Adaptation

　　For macro base station selection, priority shall be given to confirming the full-band coverage capability of the sub-6GHz band (3.3-5.0GHz), with VSWR meeting ≤1.2:1 across this range; for micro base stations deployed in the millimeter-wave band, focus shall be on verifying the VSWR stability within the 24-40GHz range to avoid indicator degradation at the edge of the frequency band.

　　Power and Scenario Matching

　　Splitters for tower-top deployed macro base stations shall support continuous power of 50W or more, with IP65 waterproof and anti-vibration designs; splitters for indoor micro base stations or Distributed Antenna Systems (DAS) can select the 20-30W power level, focusing on miniaturization (size ≤150×100×50mm) and low-power characteristics to adapt to dense installation in cabinets.

　　Considerations for Environmental Adaptability

　　For outdoor deployment, additional verification of temperature cycle performance (after 100 cycles of -40℃~+65℃, VSWR change ≤0.05) and corrosion resistance (salt spray test ≥500 hours) is required; for indoor deployment, attention shall be paid to Electromagnetic Compatibility (EMC) to meet standards such as EN 301 489 and avoid interference with other base station equipment.

　　Signal Compensation Coordination

　　16-way splitters have fixed insertion loss and shall be designed in coordination with base station pre-amplifiers or Radio Remote Units (RRUs): if the RRU output power is insufficient, a splitter integrated with Low Noise Amplification (LNA) function can be selected, with the amplification gain controlled at 10-15dB. It is necessary to ensure that the VSWR increment introduced by the amplifier is ≤0.03 to avoid degradation of the overall link reflection indicator.

　　IV. Industry Applications and Technical Adaptation

　　Adaptation to 5G Base Station Deployment Scenarios

　　In the Massive MIMO (massive antenna system) of macro base stations, low VSWR 16-way splitters are used to evenly distribute the RRU output signal to 16 antenna units. The characteristic of VSWR ≤1.2:1 can reduce the impact of signal reflection on beamforming accuracy, ensuring signal stability when multiple users access simultaneously; in micro base station distributed coverage scenarios (such as shopping malls, subways), splitters shall be designed with miniaturization, embedded in walls or ceilings, while maintaining low VSWR characteristics to avoid signal reflection issues caused by limited installation space.

　　Coordination with 5G Core Technologies

　　When adapting to the beamforming technology of 5G networks, low VSWR splitters can reduce the signal reflection difference between various antenna ports, ensuring that the beam pointing accuracy deviation is ≤1°; in Ultra-Reliable Low-Latency Communication (URLLC) scenarios, low VSWR characteristics reduce the round-trip reflection loss of signals, helping to meet the 1ms latency requirement. In addition, splitters shall support a status monitoring interface with the base station network management system, providing real-time feedback on key indicators such as VSWR and insertion loss, facilitating maintenance personnel to quickly troubleshoot link faults.

Read recommendations:

wideband rf circulator

omni directional outdoor antenna

50 amp to 30 amp splitter

Selection Guide for RF Isolators and Circulators Used in 5G Communication Systems

Ultra-Wideband (UWB) RF Isolators