Method for producing a hyperfrequency component comprising a plurality of elements including an yttrium iron garnet ferrite, characterised in that said ferrite is prepared by a method comprising the following steps in succession: - the raw materials containing the components of the ferrite are weighed in proportions such that the final ferrite obtained has the following composition: Y a TR b Bi c Fe d Al e In f Ca g Cu h Zr i V j Co k Si l O 12 ± γ where: * -1 ≤ γ ≤ 1 * 3(a+b+c+d+e+f) + 2(g+h+k) + 4(i+l) + 5j = 24 ± 2γ * 1 ≤ a ≤ 3.5 * 0 ≤ b ≤ 1.5 * 0.1 ≤ c ≤ 1, preferably 0.65 ≤ c ≤ 1 * 4 ≤ d ≤ 5 * 0 ≤ e ≤ 1.5 * 0 ≤ f ≤ 0.8 * 0 ≤ g ≤ 1 * 0.01 ≤ h ≤ 0.05 *0 ≤ i ≤ 0.2 * 0 ≤ j ≤ 0.8 * 0 ≤ k ≤ 0.5 * 0 ≤ l ≤ 0.5 where TR is a rare earth chosen preferably from Gd, Dy or Ho, or a mixture of rare earths; - said raw materials are mixed and ground in a first grinding operation to obtain a first powder; - said first powder is calcined at from 800 to 1100°C in air, nitrogen or oxygen; - the calcined powder is ground in a second grinding operation to obtain a second powder; - organic products such as binders and/or deflocculating agents and/or surfactants are mixed with said second powder to obtain a paste; - said paste is deposited in the form of a layer or of a superposition of layers; - said layer or superposition of layers is preferably pressed at a pressure of from 100 to 200 bar; - said pressed layer or superposition of layers is sintered to obtain the ferrite, sintering taking place between 850 and 1150°C, preferably between 900 and 1000°C, for from 30 minutes to 3 hours and, during sintering, said ferrite is attached to at least one of said other elements of said component or to a precursor of said element by a co-sintering method, and in that at least one of said elements other than the ferrite is a permanent magnet, such as a hexaferrite or a Sm-Co alloy or a Nd-Fe-B alloy. - the raw materials containing the components of the ferrite are weighed in proportions such that the final ferrite obtained has the following composition: Y a TR b Bi c Fe d Al e In f Ca g Cu h Zr i V j Co k Si l O 12 ± γ where: * -1 ≤ γ ≤ 1 * 3(a+b+c+d+e+f) + 2(g+h+k) + 4(i+l) + 5j = 24 ± 2γ * 1 ≤ a ≤ 3.5 * 0 ≤ b ≤ 1.5 * 0.1 ≤ c ≤ 1, preferably 0.65 ≤ c ≤ 1 * 4 ≤ d ≤ 5 * 0 ≤ e ≤ 1.5 * 0 ≤ f ≤ 0.8 * 0 ≤ g ≤ 1 * 0.01 ≤ h ≤ 0.05 *0 ≤ i ≤ 0.2 * 0 ≤ j ≤ 0.8 * 0 ≤ k ≤ 0.5 * 0 ≤ l ≤ 0.5 where TR is a rare earth chosen preferably from Gd, Dy or Ho, or a mixture of rare earths; * -1 ≤ γ ≤ 1 * 3(a+b+c+d+e+f) + 2(g+h+k) + 4(i+l) + 5j = 24 ± 2γ * 1 ≤ a ≤ 3.5 * 0 ≤ b ≤ 1.5 * 0.1 ≤ c ≤ 1, preferably 0.65 ≤ c ≤ 1 * 4 ≤ d ≤ 5 * 0 ≤ e ≤ 1.5 * 0 ≤ f ≤ 0.8 * 0 ≤ g ≤ 1 * 0.01 ≤ h ≤ 0.05 *0 ≤ i ≤ 0.2 * 0 ≤ j ≤ 0.8 * 0 ≤ k ≤ 0.5 * 0 ≤ l ≤ 0.5 - said raw materials are mixed and ground in a first grinding operation to obtain a first powder; - said first powder is calcined at from 800 to 1100°C in air, nitrogen or oxygen; - the calcined powder is ground in a second grinding operation to obtain a second powder; - organic products such as binders and/or deflocculating agents and/or surfactants are mixed with said second powder to obtain a paste; - said paste is deposited in the form of a layer or of a superposition of layers; - said layer or superposition of layers is preferably pressed at a pressure of from 100 to 200 bar; - said pressed layer or superposition of layers is sintered to obtain the ferrite, sintering taking place between 850 and 1150°C, preferably between 900 and 1000°C, for from 30 minutes to 3 hours and, during sintering, said ferrite is attached to at least one of said other elements of said component or to a precursor of said element by a co-sintering method, and in that at least one of said elements other than the ferrite is a permanent magnet, such as a hexaferrite or a Sm-Co alloy or a Nd-Fe-B alloy.