Antenna array architecture with electrically conductive columns between substrates
An antenna apparatus includes an antenna substrate with opposite first and second surfaces; and a PCB having opposite first and second surfaces. Antenna elements are disposed at the first surface of the antenna substrate. Electrically conductive columns, each having a first end attached to the second surface of the PCB and a second end attached to the second surface of the antenna substrate, secure the PCB to the antenna substrate and provide an electrical interconnect between the PCB and the antenna substrate. RFIC chips are each attached to the second surface of the antenna substrate and are coupled to the antenna elements. At least one circuit element is attached to the first surface of the PCB and electrically coupled to at least one of the RFIC chips through at least one of the electrically conductive columns.
1. An antenna apparatus comprising:
an antenna substrate having opposite first and second surfaces;
a plurality of antenna elements disposed at the first surface of the antenna substrate;
a printed circuit board (PCB) having opposite first and second surfaces;
a plurality of deformable electrically conductive columns, each comprising at least one of springs, micro-coaxial cables, and cylinders with copper spiral wrappings, and each having a first end attached to the second surface of the PCB and a second end attached to the second surface of the antenna substrate, to secure the PCB to the antenna substrate and to provide an electrical interconnects between the PCB and the antenna substrate;
a plurality of radio frequency integrated circuit (RFIC) chips each attached to the second surface of the antenna substrate and coupled to the plurality of antenna elements; and
at least one circuit element attached to the first surface of the PCB and electrically coupled to at least one of the RFIC chips through at least one of the electrically conductive columns.
2. The antenna apparatus of claim 1 , wherein at least one of the electrical interconnects is a radio frequency (RF) interconnect to communicate an RF signal.
3. The antenna apparatus of claim 1 , wherein at least one of the electrical interconnects is a direct current (DC) interconnect to communicate a DC signal.
4. The antenna apparatus of claim 1 , wherein at least one of the electrical interconnects is a data control signal interconnect to communicate a data control signal.
5. The antenna apparatus of claim 4 , wherein the data control signal is provided to multiple ones of the RFIC chips to adjust phase shifters therein to create a phased array.
6. The antenna apparatus of claim 1 , wherein the PCB and the antenna substrate have different coefficients of thermal expansion (CTEs), and the columns are configured to deform by flexing, compressing or stretching to provide relief of stress due to the different CTEs.
7. The antenna apparatus of claim 1 , wherein the at least one circuit element comprises an IC chip that provides control signals and/or bias voltages to the RFIC chips through the at least one of the columns and a conductive trace layer at the second surface of the antenna substrate.
8. The antenna apparatus of claim 7 wherein the IC chip is a field-programmable gate array (FPGA).
9. The antenna apparatus of claim 1 , wherein the at least one circuit element comprises a DC connector that provides a DC voltage to the RFIC chips through the at least one of the columns and a conductive trace layer at the second surface of the antenna substrate.
10. The antenna apparatus of claim 1 , wherein the at least one circuit element comprises an RF connector that routes an RF signal to or from the RFIC chips through the at least one of the columns.
11. The antenna apparatus of claim 10 , wherein:
the plurality of columns comprise a first column and second and third columns on opposite sides of the first column; and
the RF connector is coupled to the RFIC chips through a ground-signal-ground interconnect comprising the first column serving as a signal interconnect and the second and third columns serving as respective ground interconnects.
12. The antenna apparatus of claim 1 , wherein:
the second surface of the antenna substrate comprises an antenna ground plane having openings for interconnects to electrically couple the RFICs and the antenna elements; and
the RFIC chips have respective ground connection points electrically coupled to the antenna ground plane.
13. The antenna apparatus of claim 1 , wherein each of the RFIC chips has a lower surface attached to the second surface of the antenna substrate through a plurality of electrical connection joints, and an upper surface separated from the second surface of the PCB by an air gap.
14. The antenna apparatus of claim 13 , wherein the plurality of electrical connection joints are solder bumps or copper pillars.
15. The antenna apparatus of claim 1 , wherein the plurality of electrically conductive columns comprise the springs.
16. The antenna apparatus of claim 1 , wherein;
the plurality of electrically conductive columns comprise the cylinders with copper spiral wrappings;
the cylinders are solder columns; and
the electrically conductive columns form a column grid array (CGA).
17. The antenna apparatus of claim 1 , wherein the RFIC chips each comprise at least one of a receive amplifier, a transmit amplifier and a phase shifter.
18. The antenna apparatus of claim 1 , wherein the RFIC chips are each coupled to one or more of the antenna elements through a respective via formed within the antenna substrate.
19. The antenna apparatus of claim 1 , further comprising a beamforming network (BFN) formed on at least one dielectric substrate situated between the plurality of RFIC chips and attached to the second surface of the antenna substrate.
20. The antenna apparatus of claim 19 , wherein the antenna substrate comprises:
a first layer adjacent to the antenna elements;
a second layer proximate to the RFICs; and
an antenna ground plane between the first and second layers;
wherein the second layer comprises a transmission line coupling the plurality of RFIC chips to the BFN.
21. The antenna apparatus of claim 20 , wherein the antenna ground plane includes openings for first vias traversing therethrough, the first vias connecting the RFIC chips to the antenna elements; and
the second layer includes a plurality of second vias that couple the antenna ground plane to the RFIC chips.
22. The antenna apparatus of claim 1 , wherein the antenna substrate comprises a patterned metal layer that forms a beamforming network for the antenna apparatus.
23. The antenna apparatus of claim 1 , further comprising a plurality of serial peripheral interface (SPI) chips attached to the second surface of the antenna substrate and coplanarly arranged with and coupled to the RFIC chips, the SPI chips being coupled to the at least one circuit element through at least one of the solder columns.
24. The antenna apparatus of claim 1 , wherein the plurality of electrically conductive columns comprise the micro-coaxial cables.