2.3.6 Electromagnetic parameter test
The specimen for the electromagnetic parameter test is a coaxial ring. The outer diameter is 23mm, the inner diameter 10mm, and the height 20mm. Before testing, polish the surface of the specimen cured to 28 days until there are no burrs and chamfers. Then, it is dried in a drying oven to a constant weight with the temperature of 50°C and then kept in a dry environment. The test frequency band of electromagnetic parameters is 0.2 to 5 GHz, and the coaxial transmission/reflection method is adopted by using a vector network analyzer produced by China Ceyear Technology Co., Ltd.