Patent ID: 7286025

Claim:
A circulator element comprising: a garnet type ferrite material; and a permanent magnet for applying a direct-current magnetic field to said garnet type ferrite material, wherein S 11 represents the saturation magnetization of said garnet type ferrite material at a temperature T 1 , S 12 represents one at a temperature T 2 , and S 13 represents one at a temperature T 3 ; and S 21 represents the saturation magnetization of said permanent magnet at a temperature T 1 , S 22 represents one at a temperature T 2 , and S 23 represents one at a temperature T 3 , where T 1 <T 2 <T 3 , and the saturation magnetizations S 11 , S 12 , S 13 , S 21 , S 22 and S 23 are relative values providing that the saturation magnetizations at the temperature T 2 is 1 , and wherein the relations |(S 12 −S 11 )/(T 2 −T 1 )|<|(S 22 −S 21 )/(T 2 −T 1 )| and |(S 13 −S 12 )/(T 3 −T 2 )|>|(S 23 −S 22 )/(T 3 −T 2 )| are satisfied; wherein T 1 =−35° C., T 2 =25° C. and T 3 =85° C.