DAS Cable Loss Equalization via Hybrid Antenna Units
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Solution Overview
Problem
Distributed Antenna Systems (DAS) face challenges due to varying antenna cable lengths, leading to disparate signal attenuation and coverage radii, which complicate antenna location planning, increase costs, and affect uplink dynamic range, especially in systems handling multiple wireless services at different frequencies.
Innovation Solution
A system that includes a loss measurement component and an equalization component to estimate and adjust signal losses across cable runs, using RF measurement signals to ensure consistent signal levels at each antenna, regardless of cable length or frequency, through the use of hybrid passive-active antenna units with amplification blocks for specific or multiple frequency bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If cable lengths are varied to accommodate different antenna locations, then antenna placement flexibility is improved, but signal attenuation disparity increases
Solution Approach 1:
The patent applies local quality by introducing individual equalization components at each antenna cable connection point. Each equalization component is specifically configured to compensate for the unique cable length and attenuation characteristics of its associated cable run, thereby equalizing signal levels across all antennas despite varying cable lengths. This localized compensation approach maintains antenna placement flexibility while eliminating signal attenuation disparity.
2Area of stationary object
If cable length is increased to extend coverage area, then coverage radius is improved, but signal attenuation increases
Solution Approach 1:
The patent implements feedback through equalization components that receive feedback signals from the main transmission line and automatically adjust their attenuation characteristics. The equalization components are configured based on measured or calculated cable losses, creating a closed-loop system that compensates for signal attenuation in real-time. This allows extended cable runs to achieve larger coverage areas while maintaining adequate signal levels through automatic feedback-based compensation.
3Manufacturing precision
If equalization components are added to compensate for cable losses, then signal level consistency is improved, but device complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-configuring equalization components with predetermined attenuation values that correspond to specific cable length ranges or attenuation characteristics. Rather than requiring complex real-time adjustment mechanisms, the equalization components are pre-set during installation based on cable measurements, simplifying the overall system architecture while achieving precise signal level consistency across all antennas.
4Adaptability or versatility
If multiple frequency bands are supported, then service versatility is improved, but frequency-dependent attenuation varies
Solution Approach 1:
The patent addresses frequency-dependent attenuation by configuring equalization components with frequency-specific attenuation characteristics. Each equalization component is designed to compensate for cable losses across multiple frequency bands, with its attenuation profile tailored to match the frequency response of the associated cable run. This allows the system to support multiple wireless services across different frequency bands while maintaining consistent signal levels despite varying frequency-dependent cable attenuation.
Data Source
AI summary
The invention is directed to a method and system for equalizing the signal losses over cable runs in a Distributed Antenna System (DAS). In a DAS, two or more antennae are connected to the system by cable runs that can vary widely in length. As a result, the signal loss over a given cable run can also vary widely which can impact the design and deployment of the DAS and reduce antenna spacing. In addition, for a broadband DAS that supports many frequency bands or ranges using a common antenna unit, the signal losses vary with respect to frequency further making it difficult to equalize the cable losses. According to one embodiment of the invention, the method and system provide for measuring and adjusting the signal losses of each cable run to be a predefined value. According to another embodiment of the invention, the DAS can include a hybrid passive-active antenna unit which includes a frequency multiplexer that separates the signal into frequency bands or ranges that are connected to an antenna element associated with a particular frequency band or range. Where a single frequency band needs to be amplified (or attenuated), a single band amplification block (SBAB) can be inserted in the connection between the frequency multiplexer and the antenna element to amplify (or attenuate) the desired frequency band. Where more than one frequency band need to be amplified (or attenuated), a multiband amplification block (MBAB) can be inserted in the connection between the frequency multiplexer and the appropriate antenna element to amplify (or attenuate) the desired frequency bands.