EN
The performance parameter that is of utmost importance in the present RF systems, such as phased array radar or 5G beamforming and satellite communications is a signal phase consistency. In the case of phase difference in a number of cables the effects include beam steering errors, loss of signal coherence and loss of measurement accuracy. As an RF company with over 20 years of experience, Linkworld of over 20 years, we are familiar with how the process of phase consistency is an engineer-specific exercise requiring planning. This guide reviews the four major considerations to be made when undertaking the multi-cable deployments in order to have the same phases.
Phase Stability vs. Phase Matching
These two concepts are alike and not alike. The ability of a single cable to be an electrically constant electrical length irrespective of the environmental forces like flexure, vibration, and temperature changes may be considered as phase stability. Phase-stable cables are of high quality and typically they are 2 to 6 degrees at flexure. In comparison, phase matching is the relative error of various cable assemblies in a system. It can be absolute matching (meets a given tolerance), relative matching (assemblies matched in a batch) or delay-matched pairs. To arrive at the right design of a system, the first thing you should do is to know the kind of system your application requires. Linkworld helps customers in phase specifications determination as per what they need in the form of multi-channel requirements.
Material Selection and Cable Construction
Phase-consistent cable assemblies are grounded on materials and construction. Dielectric materials are dominated in phase behavior. Dielectrics made from the conventional PTFE material have a large phase change with temperature due to thermal expansion. Special cables with high phase dielectric materials based on fluoropolymers are used in the case where phase consistency is required under various circumstances where the phase characteristic is found to be consistent over extended temperature ranges. These cables can indicate phase variation less than 600 parts per million in -40°C to +85°C. Also, cable pre-conditioning i.e. subjecting the cables to heat and mechanical forces during the manufacture process, stabilizes the transmission line. The custom cable assemblies of Linkworld are added with these high-grade materials as well as curing processes to achieve high quality in the phase of consistency.
Phase Matching Techniques and Tolerances
The stage of careful matching requires through intensive measuring and manufacturing. The different needs can be addressed in three major ways. Absolute matching sets a certain electrical length tolerance of any particular assembly, and current systems are down to ±5 picoseconds. Relative matching pair assemblies to achieve phase differences of very fine differences typically ≤1 picosecond on important applications. Lot matching offers uniformity to bigger quantities of production. Industry rule-of-thumb tolerances have evolved from 1 degree/GHz to 0.5 degree/GHz frequencies of up to 18 GHz. Various match assemblies are manufactured by Linkworld based on the most demanding requirements by use of precision phase measuring and trimming.
System Design Considerations
System architecture is important with regard to consistency of phases other than in choice of components. In beam forming, it is essential that there should be uniformity on the phase of each element as it is in the case of phased array. At different environmental parameters within the cables like temperature gradient across the array, phase variations occur that cause distortion of the radiation pattern. These effects are minimized with the help of cables that are phase-stable. The routing in the same direction and with the same bend radius on all channels is ensured to provide all assemblies with the same mechanical load. Color-coded connectors allow error reduction in connector errors during installation. Linkworld provides engineering support services to its clients in the process of achieving the best-phase consistency of their system architectures, during the design and implementation.
The dimension of performance of signal phase stability is of great significance in multi-channel RF systems. Phase coherence can only be acquired through special engineering either through phase-stable cables that do not change with the environmental conditions or phase-matched assemblies that retain the same electric length. As more and more uses of beamforming continue to be implemented with more and more frequent utilizations, phase consistency will only become more valued. Linkworld has over 20 years’ experience in the production of RF assemblies, and phase stable and phase matched cable assemblies, and has experience in the layout phase consistency of advanced RF systems. Call us to find out about the implementation of your multi-cable.