Vertical switched filter bank
A microwave or radio frequency (RF) device includes stacked printed circuit boards (PCBs) mounted on a flexible PCB having at least one ground plane and a signal terminal. Each of the stacked PCBs includes through-holes the sidewalls of which are coated with a conductive material. Microwave components are mounted on the flexible PCB within the through-holes, such that signal terminals of the components bond to signal terminals of respective through-holes. A conductive cover is mounted on the PCBs such that the cover is in electrical contact with the ground plane of the flexible PCB through the conductive material, forming shielding cavities around the components. The flexible PCB is folded such that the cover of one PCB faces the cover of the second PCB. The flexible PCB includes striplines or microstrips that carry RF or microwave signals to the signal terminals.
1. A microwave device, comprising:
a first substrate having a top surface, the top surface having at least one ground terminal and at least one signal terminal of the first substrate;
a second substrate having a first surface and an opposing second surface, the second substrate disposed over the top surface of the first substrate, the second substrate having a through-hole extending between the first surface and the second surface;
a conductive material covering sidewalls of the through-hole, and covering at least a portion of the first surface and at least a portion of the second surface at rim edges of the through-hole, the conductive material on the first surface in electrical contact with the at least one ground terminal of the first substrate;
a microwave component disposed within the through-hole and on the top surface of the first substrate, the microwave component having a ground terminal in electrical contact with the at least one ground terminal of the first substrate, and a signal terminal in electrical contact with the at least one signal terminal of the first substrate;
a cover at least partially covering the through-hole, the cover including a conductive surface in electrical contact with the conductive material covering at least a portion of the second surface of the second substrate;
at least one transmission line coupled to the at least one signal terminal, the at least one transmission line formed in the first substrate and below the top surface of the first substrate; and
a dielectric material in the first substrate covering at least a portion of the at least one transmission line.
2. The microwave device of claim 1 , comprising:
a first ground plane and a second ground plane disposed on the first substrate, the at least one transmission line disposed between the first ground plane and the second ground plane.
3. The microwave device of claim 1 , wherein the conductive material covers all surfaces of the sidewalls of the through-hole.
4. The microwave device of claim 1 , wherein the conductive material comprises a layer of conductive material having a mesh structure.
5. The microwave device of claim 1 , comprising:
a first ground plane disposed over the top surface of the first substrate, the first ground plane, the conductive material, and the cover forming a shielding enclosure for the microwave component.
6. The microwave device of claim 1 , wherein the microwave component has a thickness between 0.045 inches to 0.055 inches.
7. A microwave device, comprising:
a first substrate having a top surface, the top surface having at least one ground terminal and at least one signal terminal of the first substrate;
a second substrate having a first surface and an opposing second surface, the second substrate disposed over the top surface of the first substrate, the second substrate having a through-hole extending between the first surface and the second surface;
a conductive material covering sidewalls of the through-hole, and covering at least a portion of the first surface and at least a portion of the second surface at rim edges of the through-hole, the conductive material on the first surface in electrical contact with the at least one ground terminal of the first substrate;
a microwave component disposed within the through-hole and on the top surface of the first substrate, the microwave component having a ground terminal in electrical contact with the at least one ground terminal of the first substrate, and a signal terminal in electrical contact with the at least one signal terminal of the first substrate;
a cover at least partially covering the through-hole, the cover including a conductive surface in electrical contact with the conductive material covering at least a portion of the second surface of the second substrate; and
at least one microstrip transmission line coupled to the at least one signal terminal, the at least one microstrip transmission line disposed over the top surface of the first substrate.
8. The microwave device of claim 7 , wherein a cavity extends over the at least one microstrip transmission line and is located below the first surface of the second substrate.
9. The microwave device of claim 7 , comprising:
a ground plane disposed on the first substrate, the at least one microstrip transmission line separated from the ground plane by a dielectric material.
10. A microwave device, comprising:
a first substrate having a first ground plane;
a second substrate including a plurality of through-holes having conductive sidewalls;
a plurality of microwave components disposed over the first substrate within the respective through-holes;
a conductive cover disposed over the second substrate and positioned to at least partially cover the plurality of through-holes, the cover electrically coupled to the first ground plane via the conductive sidewalls;
a plurality of transmission lines coupled to a respective signal terminal of the plurality of microwave components;
a dielectric material disposed in the first substrate covering at least a portion of each of the plurality of transmission lines; and
a second ground plane disposed on the first substrate, wherein the plurality of transmission lines are disposed non-coplanar in relation to the first ground plane and to the second ground plane.
11. The microwave device of claim 10 , wherein the first substrate includes a plurality of signal terminals, each signal terminal of the plurality of signal terminals coupled to a signal terminal of a respective microwave component of the plurality of microwave components.
12. The microwave device of claim 10 , wherein the plurality of microwave components are configured to operate within a frequency range of 300 MHz to 300 GHz.
13. The microwave device of claim 10 , wherein the conductive sidewalls include a layer of conductive material having a mesh shaped structure.
14. The microwave device of claim 10 , wherein the plurality of microwave components have a thickness between 0.045 inches to 0.055 inches.
15. A microwave device, comprising:
a first substrate having a first ground plane;
a second substrate including a plurality of through-holes having conductive sidewalls;
a plurality of microwave components disposed over the first substrate within the respective through-holes;
a conductive cover disposed over the second substrate and positioned to at least partially cover the plurality of through-holes, the conductive cover electrically coupled to the first ground plane via the conductive sidewalls; and
a plurality of microstrip transmission lines coupled to a respective signal terminal of the plurality of microwave components, at least one of the plurality of microstrip transmission lines disposed over a top surface of the first substrate, the top surface of the first substrate facing the second substrate.
16. The microwave device of claim 15 , comprising:
a plurality of cavities each extending over a respective one of the plurality of microstrip transmission lines and located below a first surface of the second substrate.
17. The microwave device of claim 15 , comprising:
a ground plane disposed on the first substrate, the plurality of microstrip transmission lines separated from the ground plane by a dielectric material.