Cable Assemblies for GPS/GNSS Modules: Important Considerations | Eteily Technologies

Introduction

For every GPS or GNSS application, the antenna is only half the battle. The connection—the cable assembly—is the critical link that transmits the extremely weak satellite signal from the antenna to the reception module. Poor cable selection or construction may quickly degrade the performance of the most powerful GNSS devices.

Engineers and integrators working with Eteily Technologies must grasp the main aspects for these RF cable assemblies in order to achieve optimal precision, sensitivity, and dependability in their positioning and timing solutions.

1. Signal Integrity: The Battle Against AttenuationGNSS.

Satellite signals, such as GPS L1 at 1575.42MHz, are naturally weak, and signal attenuation (loss) is the main obstacle to a stable connection. The cable must minimize this loss so that the receiver receives a strong enough signal for a short Time To First Fix (TTFF) and consistent, accurate tracking.

• Cable Type and Loss: Coaxial cables are utilized for GNSS since they are shielded and impedance matched.

• Thicker Cables, Less Loss: Larger diameter cables (e.g., LMR-400 equivalent) have a substantially lower loss (attenuation) per unit length than thinner, more flexible choices.

• Length is Critical: Attenuation is proportional to length. Always utilize the minimum possible cable length. For extremely long runs (e.g., above 30 meters), an inline amplifier (booster) may be required, which is normally located closer to the antenna.

• Impedance Matching: GNSS antennas and receivers have a standard impedance of 50 Ohms ($\Omega$). The cable assembly must maintain a constant 50ohm impedance throughout its length, since any mismatch generates signal reflections (Voltage Standing Wave Ratio - VSWR), degrading performance.

2. Connector Selection and Quality

The connections at each end of the cable assembly provide possible sources of signal loss and environmental failure. Selecting the appropriate kind and assuring high-quality termination is critical.

Common Connector Types:

• SMA/RP-SMA: Because of their tiny size and outstanding RF performance at high frequencies, these connectors are widely used in smaller commercial and industrial modules.

• N-Type: Typically used for tough, high-performance outdoor antennas and base stations that require great durability and weather resistance.

• MMCX/U.FL/I-PEX: Used for internal connections to integrated GNSS modules on PCBs; prized for their small size, but provide less secure latching.

• Termination Quality: The crimping and soldering of the connection to the coaxial wire must be done properly. Poor termination is a key cause of RF signal loss and increased noise. Eteily Technologies guarantees precision-engineered terminations to provide maximum signal route integrity.

3. Environmental and mechanical durability.

The material, shielding, and connector housing of the cable jacket are determined by the working environment, particularly in outdoor or industrial applications.

Weather Resistance (for Outdoor Use):

• Jacket Material: Select a jacket (such as PE or TPE) that is UV resistant to avoid sun damage and resistant to dampness, chemicals, and severe temperatures.

• Weatherproofing: Proper weatherproofing (taping or heat shrink) is required for N-Type and other outdoor connections to avoid water entry, which can significantly reduce signal quality and limit cable lifespan.

Flexibility and Installation:

• Bend Radius: Thicker, low-loss cables, such as LMR-400, have a greater minimum bend radius. If the cable must be routed through tight places or around sharp corners, a more flexible, smaller diameter cable (such as LMR-240 or LMR-195) may be necessary, balancing flexibility with acceptable signal loss.

• Shielding: High-quality double or triple shielding (foil and braid) is required to protect the weak GNSS signal from external electromagnetic interference (EMI) from adjacent electronics, radio transmitters, or power lines, which is a typical problem in complicated installations.

4. Power delivery (active antennas)

Many high-performance GNSS antennas are active, which means they have a Low-Noise Amplifier (LNA) that boosts the weak satellite signal before it reaches the cable.

• DC Power Requirements: The cable assembly must be able to transport the DC voltage (usually 3V or 5V) from the GNSS module to power the LNA in the active antenna.

• Cable Loss Effect: While the LNA amplifies the signal, the DC power signal suffers loss along the cable. For very lengthy cable lengths, account for the DC voltage loss so that the LNA obtains the minimum needed operating voltage. A high-quality LNA will have its noise figure as near to the antenna element as feasible to maximize performance.

Conclusion : The Eteily Technologies Advantage

Choosing the appropriate cable assembly is an integral aspect of the system design, not an afterthought. Eteily Technologies India Pvt. Ltd.  specializes in unique, high-performance RF wire assemblies designed for demanding GNSS/GPS applications.

We guide you through the trade-offs—balancing low attenuation, connection robustness, and flexibility—to produce a proven, precision-matched solution that enhances the performance of your GNSS module. Do not let a low-quality cable be the weakest link in your accurate positioning system.

Contact Us

Eteily Technologies India Pvt. Ltd.

📫 Address: B28 Vidhya Nagar, Near SBI Bank,

 📍  District: Bhopal, PIN: 462026, Madhya Pradesh

🌐 Website: https://eteily.com