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Power rating of RF Isolator and Circulator |
Author : handsun co Date : 12/16/2013 3:51:54 PM |
A proper connector selection and an optimized internal geometry are required to maximize the peak power capability of a particular circulator or isolator. The input power to a circulator or isolator can be supplied from a CW or a pulsed source. In the case of a pulsed source both the peak and average power components of the pulse train should be specified in order to determine an adequate safety margin for a particular circulator or isolator. The peak power level can also cause an increase in the insertion loss in a below resonance design, due to non-linearity effects of the ferrite material. This increase can occur at peak power levels considerably lower than that required for breakdown or arcing. The increased insertion loss will cause more power to be dissipated in the ferrite region of the device which will result in overheating. Higher peak power levels can be obtained by using a special ferrite material. The peak power can be at a high enough level to cause breakdown or arcing. This generally results in permanent degradation of electrical performance. The average power rating of a circulator or isolator is determined by the insertion loss, the internal geometry of the ferrite region, and the type of cooling available. The insertion loss of a circulator or isolator will cause some of the average power to be absorbed and dissipated in the ferrite region as heat. Adequate cooling is necessary to ensure the ferrite material does not reach an excessive temperature. Mounting to a heat sink for cooling is sufficient in many cases if the average power is moderate. In high power applications, a component with a high VSWR connected to the output port of an isolator will reflect a substantial amount of power. The temperature of the ferrite region as well as the internal voltage will increase causing the performance to deteriorate or arcing to occur before full rated input power can be realized. Circulators and isolators that must meet stringent peak and average power levels require design considerations of many parameters. The normal and worst case load VSWR conditions and the available cooling must be specified when ordering high power isolators or circulators. Let me introduce a high power capability product---water cooling circulator, few MW ranting for power capability. You can send email to us for more details information. |
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