Electromagnetic band gap microwave filter
View Patent ↗A microwave filter is formed from an electromagnetic band gap structure. The electromagnetic band gap structure includes a periodic array of metal features ( 16, 42, 44, 50 ) formed within a dielectric matrix ( 14, 52 ). A defect feature ( 17, 48 ) is formed within the periodic array of metal features ( 16, 42, 44, 50 ) in order to create a pass band within a stop band region.
1. An electromagnetic band gap filter, comprised of:
a dielectric matrix;
a lattice formed within said dielectric matrix, that has a stop
band response that includes zero frequency; and
a defect feature formed in said lattice, thereby forming a pass band within said stop band at a microwave frequency;
wherein said defect feature is comprised of a capacitor placed within said periodic lattice.
2. An electromagnetic band gap filter, comprised of:
a dielectric matrix;
a lattice formed within said dielectric matrix that has a stop
band response that includes zero frequency; and
a defect feature formed in said lattice, thereby forming a pass band within said band at a microwave frequency;
wherein said periodic lattice is comprised of a row of metallic rods
3. An electromagnetic band gap filter, comprised of:
a dielectric matrix;
a lattice formed within said dielectric matrix that has a stop
band response that includes zero frequency; and
a defect feature formed in said lattice, thereby forming a pass band within said band at a microwave frequency;
wherein said periodic lattice is comprised of a row of capacitors.
4. The filter of claim 3 , wherein said defect feature is comprised of a defect capacitor having a capacitance different from said capacitors forming the periodic lattice.
5. An electromagnetic band gap filter, comprised of:
a dielectric matrix;
a lattice formed within said dielectric matrix that has a stop
band response that includes zero frequency; and
a defect feature formed in said lattice, thereby forming a pass band within said band at a microwave frequency;
wherein said lattice is comprised of:
a row of metallic posts having alternating heights; and
a plurality of metallic plates placed proximal to the ends of each metal post in said row of metal posts, wherein said metal plates overlap thereby forming a periodic array of capacitors.
6. An electromagnetic band gap filter, comprised of:
a dielectric matrix;
a lattice formed within said dielectric matrix that has a stop
band response that includes zero frequency; and
a defect feature formed in said lattice, thereby forming a pass band within said band at a microwave frequency;
wherein said defect is comprised of an oversized metal plate formed in the periodic lattice.
7. An electromagnetic band gap filter, comprised of:
a dielectric matrix;
a lattice formed within said dielectric matrix that has a stop
band response that includes zero frequency; and
a defect feature formed in said lattice, thereby forming a pass band within said band at a microwave frequency;
wherein the periodic lattice couples a signal line to a ground line, thereby selectively rejecting signals propagating through said signal line and said ground line.
8. A microwave filter, comprised of:
lattice means to form an electromagnetic band gap structure within a dielectric matrix, thereby creating a transmission spectrum having a stop band that includes zero frequency; and
defect means to form a defect in said periodic metal lattice, thereby forming a pass band in said stop band at a microwave frequency;
wherein said lattice means is comprised of vias formed in said dielectric matrix.