Designers may take coax cable for granted in cellular basestations, yet it’s the critical link between the transceivers and antennas. Cable attenuation is a major performance factor, as its physical characteristics help it endure the weather. Andrew Solutions recently released the results of tests on its smoothwall aluminum cable for wireless networks that shows it is worth considering for installing new or replacement cable (Fig. 1).

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Telab BV, a third-party independent laboratory specializing in testing and international certification of electronic, electrical, and machine equipment, subjected Andrew’s Heliax 2.0 FXL aluminum cable to 10 rounds of environmental testing, proving its durability in extreme temperatures. Heliax FXL’s solid triple-bonded construction also demonstrated superior crush resistance while surpassing or meeting the electrical performance specifications set by Telab for 26 other trials (Fig. 2).

Figure 1. All of the “pipes” on cell towers are coax cables that not only meet stringent RF specifications but also major weather challenges as well as potential installation mishaps.

Telab, the leading test lab in China, conducted multiple stress tests on Heliax FXL based on the China Communications Standard Association YD/T 1092-2004 standard, which defines performance requirements for coaxial cable used in the nation’s wireless communications industry. Andrew submitted Heliax FXL to Telab to test the long-term reliability of its cable. Major operators worldwide have been testing and deploying FXL smoothwall aluminum cable for almost a decade with more than 48 million feet installed in wireless networks globally.

During the testing, Heliax FXL successfully passed 10 cycles of rising then decreasing temperatures, from 25°C to 80°C and back to 25°C, with negligible degradation in attenuation and voltage standing wave ratio (VSWR), which are key performance metrics for wireless cable. The cable also showed flat panel strength 40% higher than expected, proving it can withstand accidental missteps and not get damaged.

Heliax FXL additionally passed an accelerated salt fog trial, exhibiting the cable’s resistance to corrosion. Furthermore, the cable displayed superior results in passive intermodulation (PIM) testing at the 900-MHz band, exhibiting –163 dBc when the expected range is –140 to –150 dBc. A lower PIM reading means less likelihood of interference signals in the receive band.

Generally surpassing the electrical performance of leading copper cables, Heliax FXL is Andrew’s lower-cost transmission line solution. Its solid triple-bonded construction adds crush and tensile strength that far exceeds corrugated cables. It also provides maximum RF coverage due to better return loss and attenuation that surpasses or equals leading copper cables. Lighter than all-copper cables, Heliax FXL can help reduce tower loading and freight costs as well.