The main phase characteristic temperature , the temperature stable phase characteristics and temperature phase tracking characteristics ;
Temperature phase change : refers to variations in temperature , Cable RF signal phase changes through a size , which is generally used PPm to indicate that is a relative amount , generally refers to the number of PPM per meter , if you want to base the absolute amount of the use of the formula can.
Temperature stabilization phase: a predetermined value when the temperature change ( usually refers to +50 ° C -10 ° C temperature change ) , the phase change temperature in the range of less than 500PPM, the temperature is generally thought to be stable phase cable .
Temperature phase tracking : that temperature changes , two or more identical issue with Cable phase varies with temperature . For example, while one type of cable in the -10 degrees Celsius to 50 degrees Celsius change , phase tracking can guarantee millionth order .
Phase temperature and temperature stability are relative phase tracking amount due to the size of the cable itself determines the structure and materials used ( the structure of the material between the layers , the medium , and the uniformity of the dielectric material , the production of the inner conductor etc. ) , before making a Cable assembly have been identified , and the effects of these two parameters Cable assembly process of the production process is relatively small .
In our practical use, we tend to be more concerned about the amount of change in the absolute phase of Cable assembly , which is calculated as the amount of change : detφ = φ0 * PPM / 1,000,000
Wherein the absolute phase φ0 Cable assembly length , and this generally refers to a phase length results tested at room temperature ,
φ0 = L * √ E * F * 360 °, where : L is the physical length of the cable ( unit: m ), E is the dielectric constant of the cable dielectric ( dielectric constant is usually PRFE 2.1), F test corresponding frequency ( unit : GHz),
Can generally be calculated as follows :
Φ (20 ℃) = 360 ° * L * / λ
L: Cable Assemblies Length ( m ) What is the temperature phase stable cable
E: permittivity
λ: Wavelength = C / √ E / FC: speed of light ( m / s ) F: Frequency (GHz)
In actual use, the temperature and the temperature of the stationary phase by phase tracking is not equal to the work with the late correction , so there is a temperature change in the requirements of the application must pay attention to the problem of temperature stabilization phase ; in Cable assembly has a plurality of phase reference request phase temperature tracking is a factor that must be considered .
Phase affected by temperature solution: semi-rigid cable generally used for high temperature , cold and other treatment ;
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