Low loss tangent dielectric based on spinel-structured oxide
Disclosed herein are embodiments of high Q, temperature stable materials with low dielectric constants. In one aspect, a low loss dielectric material includes one or more transition metal oxides based on the (Zn, Ni, Co)O—Al 2 O 3 —TiO 2 system comprising an aluminate comprising one of cobalt (Co) or nickel (Ni) crystallized in a spinel structure. The low loss dielectric material additionally comprises one or more of: a titanate comprising the one of Co or Ni crystallized in a spinel structure, an aluminum oxide and a titanium oxide crystallized in a rutile structure.
1 . A low loss dielectric material for radio frequency applications, comprising:
an aluminate including one of cobalt (Co) or nickel (Ni) crystallized in a spinel structure; and
a titanate including one of Co or Ni crystallized in a spinel structure,
wherein the low loss dielectric material has a loss tangent less than 0.0001, a dielectric constant of 8-15 and a temperature coefficient of resonant frequency having a magnitude less than 20 ppm/° C.
2 . The low loss dielectric material of claim 1 , wherein the aluminate comprises NiAl 2 O 4 and the titanate comprises Ni 2 TiO 4 .
3 . The low loss dielectric material of claim 2 , wherein the NiAl 2 O 4 and the Ni 2 TiO 4 form a solid solution including Ni 1+x Al 2-2x Ti x O 4 , wherein x is greater than 0 and less than or equal to 0.5.
4 . The low loss dielectric material of claim 1 , further comprising one or both of NiTiO 3 and Ni 5 TiO 7 .
5 . The low loss dielectric material of claim 1 , wherein the aluminate comprises CoAl 2 O 4 and the titanate comprises includes Co 2 TiO 4 .
6 . The low loss dielectric material of claim 5 , wherein the CoAl 2 O 4 and the Co 2 TiO 4 form a solid solution including Co 1+x Al 2-2x Ti x O 4 , where x is greater than 0 and less than or equal to 0.5.
7 . The low loss dielectric material of claim 5 , further comprising CoTi 2 O 5 .
8 . The low loss dielectric material of claim 1 , wherein one or both of the aluminate and the titanate further comprise zinc.
9 . The low loss dielectric material of claim 8 , wherein the aluminate comprises (Zn 1-y Co y )Al 2 O 4 and the titanate comprises (Zn 1-z Co z ) 2 TiO 4 , and each of y and z is greater than zero and less than 1.
10 . The low loss dielectric material of claim 9 , wherein the (Zn 1-y Co y )Al 2 O 4 and the (Zn 1-z Co z ) 2 TiO 4 form a solid solution including (Zn 1-y Co y ) 1+x Al 2-2x Ti x O 4 , and x is greater than 0 and less than 0.5.
11 . The low loss dielectric material of claim 8 , wherein the aluminate comprises (Zn 1-y Ni y )Al 2 O 4 and the titanate comprises (Zn 1-z Ni z ) 2 TiO 4 , and each of y and z is greater than zero and less than 1.
12 . The low loss dielectric material of claim 11 , wherein the (Zn 1-y Ni y )Al 2 O 4 and the (Zn 1-z Ni z ) 2 TiO 4 , form a solid solution including (Zn 1-y Ni y ) 1+x Al 2-2x Ti x O 4 , and x is greater than 0 and less than 0.5.
13 . A radiofrequency component comprising:
a ceramic disk formed of a low loss dielectric material, the low loss dielectric material including an aluminate including one of cobalt (Co) or nickel (Ni) crystallized in a spinel structure, and a titanate including one of Co or Ni crystallized in a spinel structure.
14 . The radiofrequency component of claim 13 , wherein the radiofrequency component comprises one or more of a co-axial resonator, a dielectric filter, an isolator and a circulator.
15 . The radiofrequency component of claim 14 , wherein the low loss dielectric material has a loss tangent less than 0.0001, a dielectric constant of 8-15 and a temperature coefficient of resonant frequency having a magnitude less than 20 ppm/° C.
16 . The radiofrequency component of claim 15 , wherein the aluminate includes one of NiAl 2 O 4 and CoAl 2 O 4 , and the titanate includes one of Ni 2 TiO 4 and Co 2 TiO 4 .
17 . The radiofrequency component of claim 15 , wherein the aluminate and the titanate form a solid solution.
18 . A method of manufacturing a component for a radio frequency device, the method comprising:
mixing component oxide powders to form a mixed powder;
calcining the mixed powder;
forming the calcined mixed powder into a ceramic disk; and
sintering the ceramic disk, thereby forming the component formed of a low loss dielectric material, the low loss dielectric material including an aluminate including one of cobalt (Co) or nickel (Ni) crystallized in a spinel structure, and a titanate including one of Co or Ni crystallized in a spinel structure.
19 . The method of claim 18 , wherein the component is selected from the group consisting of a filter, an isolator, a circulator and a resonator.
20 . The method of claim 19 , wherein the low loss dielectric material has a loss tangent less than 0.0001, a dielectric constant of 8-15 and a temperature coefficient of resonant frequency having a magnitude less than 20 ppm/° C.