隔离器用羰基铁系微波吸收材料的硅烷偶联剂改性

Modification of carbonyl iron powder microwave absorber for isolator load by silane coupling agent

用硅烷偶联剂（KH-560）对羰基铁粉表面进行改性,以环氧树脂为基体、改性前后的羰基铁粉为吸收剂制备复合微波吸收材料。采用热重、红外光谱等手段对改性后的粉体进行了表征;对试制的羰基铁粉/环氧树脂复合材料的体电阻率、击穿强度、吸收损耗进行了测试,对使用该材料的隔离器性能进行了研究。结果表明,改性羰基铁粉在树脂中分散性较好,颗粒之间的绝缘程度得到提高,改性后制备的吸收体,击穿强度达700V/mm,体电阻率为4.99×108Ω.cm,6~18GHz频率范围内吸收损耗在1.8~7.8dB/mm之间。6~18GHz边导模隔离器负载中使用该材料,器件驻波比≤1.6时,插入损耗≤1.2,隔离度≥11dB,相对带宽为100%。

Carbonyl iron powder was modified by Silane coupling agent（KH-560）,and carbonyl iron powder/epoxy resin composite material was prepared using epoxy resin as matrix and carbonyl iron powder as absorbing agent.The modified carbonyl iron powder was characterized by TG,IR etc.The electric volume resistivity,voltage breakdown strength and absorption loss of the carbonyl iron powder/epoxy resin absorber were measured,and the characteristics of isolator using the prepared absorber was tested.The results show that the dispersivity of carbonyl iron powder in epoxy resin matrix is good and the degree of insulation among carbonyl iron powder in the composite is quite high.The absorber has electric volume resistivity of 4.99×108Ω·cm,breakdown strength of 700V/mm and absorption loss of 1.8 to 7.8dB/mm in frequency range of 6 to18GHz.The isolator employing this composite absorber has a VSWR≤1.6,insertion loss≤1.2,isolation≥11dB,relative bandwidth of 100%.