Dielectric filter, antenna duplexer

A method of manufacturing a dielectric filter, comprising the steps of:

• providing resonator electrodes of metallic foil;
• embedding the resonator electrodes in a dielectric substrate to form a resonator dielectric substrate;
• and
• laminating the resonator dielectric substrate with another dielectric substrate having an conductive layer thereon to form a laminated dielectric substrate.

A dielectric filter comprising:

• first, second, and third dielectric substrates laminated together, at least one of the first, second, and third dielectric substrates includes a portion thereof having a different relative dielectric constant from other portion thereof;
• resonator electrodes on the first dielectric substrate, being electro-magnetically coupled with each other;
• an inter-stage coupling capacitor electrode on the second dielectric substrate for coupling the resonator electrodes;
• and
• an input/output coupling capacitor electrode on the third dielectric substrate for inputting and outputting a signal to the resonator electrodes.

A method of manufacturing a dielectric filter comprising the steps of:

• providing a composite dielectric block through laminating a first dielectric material and a second dielectric material having a lower dielectric constant than the first dielectric material;
• providing composite dielectric substrates through slicing the composite dielectric block in parallel with a direction of laminating the first and second dielectric materials;
• providing an inter-stage coupling capacitor electrode, resonator electrodes, and an input/output coupling capacitor electrode on the composite dielectric substrates, respectively;
• and
• laminating the composite dielectric substrates having the inter-stage coupling capacitor electrode, the resonator electrodes, and the input/output coupling capacitor electrode thereon.

A method of manufacturing a dielectric filter comprising the steps of:

• providing a composite dielectric block in green sheet form through laminating a first dielectric material in green sheet form and a second dielectric material in green sheet form having a lower dielectric constant than the first dielectric material;
• providing composite dielectric substrates in green sheet form through slicing the composite dielectric block in green sheet form in parallel with a direction of laminating the first and second dielectric materials;
• providing an inter-stage coupling capacitor electrode, resonator electrodes, and an input/output coupling capacitor electrode on the composite dielectric substrates in green sheet form, respectively;
• laminating the composite dielectric substrates in green sheet form having the inter-stage coupling capacitor electrode, the resonator electrodes, and the input/output coupling capacitor electrode thereon;
• and
• firing the laminated composite dielectric substrates in green sheet form.

A method of manufacturing a dielectric filter comprising the steps of:

• providing a ceramic dielectric block in green sheet form through laminating a first dielectric material in green sheet form and a second dielectric material in green sheet form having a lower dielectric constant than the first dielectric material;
• providing a plurality of composite dielectric substrates in green sheet form through slicing the composite ceramic dielectric block in green sheet form in parallel with a direction of laminating the first and second dielectric materials;
• firing the composite dielectric substrates in green sheet form;
• providing an inter-stage coupling capacitor electrode, resonator electrodes, and an input/output coupling capacitor electrode on the fired composite dielectric substrates;
• and
• laminating the composite dielectric substrates having the inter-stage coupling capacitor electrode, resonator electrodes, and input/output coupling capacitor electrode thereon.