Thin antenna device

Abstract

The present invention discloses an antenna device, which includes a first subassembly having a plurality of antenna elements and a second subassembly attached to the first subassembly. The second subassembly may include a plurality of components of a beamforming network encapsulated in a molding material. One or more interconnect layers may be disposed on the molding material to electrically couple the plurality of components of the beamforming network to the plurality of antenna elements. The present invention also discloses a method of manufacturing the antenna device.

Description

Technical Field

[0001] The present disclosure relates generally to antenna arrays. Background Art

[0002] Antenna arrays are currently deployed in various applications at microwave and millimeter-wave frequencies, such as in aircraft, satellites, vehicles, and base stations for general terrestrial communication. Such antenna arrays typically include microstrip radiating elements that are driven by a phase-shift beamforming circuit to generate a phased array for beam steering. In many cases, it is desirable for the entire antenna system, including the antenna array and the beamforming circuit, to occupy a minimal amount of space in a thin form while still meeting the necessary performance metrics. Summary of the Invention

[0003] In one aspect of the technology disclosed by the present invention, an antenna device includes a first subassembly having a plurality of antenna elements and a second subassembly attached to the first subassembly. The second subassembly includes a plurality of components of a beamforming network encapsulated in a molding material and one or more interconnect layers on the molding material. The one or more interconnect layers electrically couple the plurality of components of the beamforming network to the plurality of antenna elements.

[0004] The components may include integrated circuit (IC) chips having dynamically controlled phase shifters such that the antenna device can operate as a phased array.

[0005] In another aspect, a method of forming an antenna device includes: forming a first subassembly including a plurality of antenna elements; and encapsulating a plurality of beamforming components of a beamforming network in a molding material to form an embedded component structure. One or more interconnect layers may then be formed on the embedded component structure to form a second subassembly. The first subassembly may then be attached and electrically connected to the second subassembly such that the plurality of beamforming components are electrically coupled to the plurality of antenna elements. Brief Description of the Drawings

[0006] The above and other aspects and features of the disclosed technology will become more apparent from the following detailed description in conjunction with the drawings, in which like reference numerals indicate the same elements or features, where:

[0007] Figure 1 is a perspective view of an example antenna device according to an embodiment.

[0008] Figure 2A is a perspective view of an example antenna element of the antenna device.

[0009] Figure 2B is a cross-sectional view showing an example arrangement and connection technique between the antenna element and an IC chip of the antenna device.

[0010] Figure 3A An example of an antenna device 100 configured for transmission and reception operations is schematically shown.

[0011] Figure 3B Is schematically shown Figure 3A An example of the T / R circuit.

[0012] Figure 4 Is a cross-sectional view of a portion of the antenna device taken along the Figure 1 IV-IV' line.

[0013] Figure 5 Is a plan view of an example embedded component sub-assembly of the antenna device.

[0014] Figure 6 Is a flowchart depicting an example method for manufacturing the antenna device.

[0015] Figure 7 Is a flowchart of an example method for forming the embedded component sub-assembly.

[0016] Figure 8A , Figure 8B , Figure 8C , Figure 8D , Figure 8E , Figure 8F And Figure 8G Are cross-sectional views showing the corresponding steps in the method of forming the Figure 7 Embedded component sub-assembly.

[0017] Figure 9 Is a plan view of another example embedded component sub-assembly of the antenna device.

[0018] Figure 10 Is a flowchart of another example method for forming the embedded component sub-assembly.

[0019] Figure 11A , Figure 11B , Figure 11C , Figure 11D And Figure 11E Are cross-sectional views showing the corresponding steps in the method of forming the Figure 10 Embedded component sub-assembly. Detailed Description

[0020] For illustrative purposes, the following description is provided with reference to the accompanying drawings to assist in a comprehensive understanding of certain exemplary embodiments of the technology disclosed herein. This description includes various specific details to assist those of ordinary skill in the art in understanding the technology, but these details should be considered merely exemplary. When a description of well-known functions and structures may obscure the understanding of the technology by those skilled in the art, the description of well-known functions and structures may be omitted for clarity and conciseness.

[0021] Figure 1 is a perspective view of an exemplary antenna device 100 according to an embodiment. The antenna device 100 may include an antenna subassembly 110 that is attached to an embedded component subassembly 150 to form a stacked structure having a thin profile. The antenna subassembly 110 includes a plurality of antenna elements 120 that are spatially arranged on a top major surface of a substrate 117 to form an antenna array 122. The number, type, size, shape, inter-element spacing, and the way in which the antenna elements 120 are driven may be varied by design to achieve target performance metrics. Examples of such performance metrics include beam width, pointing direction, polarization, sidelobes, power loss, beam shape, etc. in a necessary frequency band. In a typical case, the antenna array 122 includes at least 16 antenna elements 120. The antenna elements 120 may be microstrip patch antenna elements as Figure 1 shown, but may be replaced with other radiator types, such as printed dipoles or slotted elements. A ground layer 119 may be formed on a bottom major surface of the substrate 117. Depending on the application, the antenna elements 120 may be connected to beamforming components for transmitting and / or receiving RF signals. The following description will assume that the antenna device 100 has concurrent transmit and receive capabilities, but other embodiments may be configured for only receiving or transmitting. In one example, the antenna elements 120 are designed to operate in a millimeter (mm) wave frequency band that is typically defined as a frequency band in the range of 30 GHz to 300 GHz. In other examples, the antenna elements 120 are designed to operate below 30 GHz.

[0022] Referring temporarily to Figure 2A , an example of the antenna elements 120 within the antenna device 100 is shown in a perspective view. (The Figure 2BThe antenna element 120 is shown in a cross-sectional view. ) The antenna element 120 can be printed on the top surface of the substrate 117 or can be disposed within the substrate 117 below the top surface. The ground layer 119, which can be metallized and printed on the bottom surface of the substrate 117, reflects signal energy to / from the antenna element 120. The substrate 117 can be a low-loss tangent material such as quartz or fused silica. This can be particularly advantageous for high-frequency operation to minimize losses. Each antenna element 120 can be driven by a corresponding microstrip probe feed 114 that extends vertically through the substrate 117 and is directly connected to the lower surface of the antenna element at point p. The microstrip probe feed 114 can be formed as a through-substrate via (TSV) (hereinafter referred to as a "via") through the substrate 117. Thus, the plurality of probe feeds 114 feeding the corresponding plurality of antenna elements 120 can be considered an array of vias extending through the dielectric 117. Point p can be selected to be at a certain position within the body of the antenna element 120 to achieve a desired polarization (e.g., circular when offset a certain distance from the center). A slit 121 can be formed in the patch element for impedance matching. Note that in an alternative design, the probe feed can be replaced with a plug-in feed and / or a non-contact coupling connection to the antenna element 120.

[0023] Still referring to Figure 1 , the embedded component subassembly 150 includes beamforming network components encapsulated within a molding material 152 to together form an embedded structure 154, which can sometimes be referred to as a reconfigured wafer. The subassembly 150 can also include one or more interconnect layers 155 (which can be interchangeably referred to herein as "redistribution layers (RDL)") formed on the molding material 152 (e.g., using a multi-step deposition process of dielectric and conductive materials) to electrically couple the beamforming network components to the antenna elements 120. Examples of such beamforming network components include: integrated circuit (IC) chips 160; transmission line segments 180 that can form a combiner / distributor network; and at least one RF feedthrough transmission line 170. The IC chips 160 can be monolithic microwave IC (MMIC) chips. In one example, the IC chips 160 are each indium phosphide (InP). In another example, the IC chips can be another semiconductor material such as gallium arsenide (GaAs), gallium nitride (GaN), etc. Any IC chip 160 can feed a number of antenna elements 120. (Herein, "feeding" an antenna element means transmitting signals to and / or receiving signals from the antenna element.)

[0024] Hereinafter, the transmission line section 180 may be interchangeably referred to as the combiner / splitter network 180. In the transmission direction, the combiner / splitter network 180 acts as a splitter that divides the RF transmission signal applied through the transmission line 170 into multiple separate transmission signals, and each separate transmission signal is applied to one of the IC chips 160 in the IC chip 160. In the reception direction, the combiner / splitter network 180 acts as a combiner that combines multiple received signals, each of which is received by a set of antenna elements 120 and routed through the IC chip 160 (and typically modified by the IC chip). Thus, the IC chips 160 may collectively include an "RF front end" electrically coupled to the antenna array 122. For transmitting signals, the RF front end may include a power amplifier that is used to amplify the RF signal applied through the transmission line 170 in a distributed manner. In the reception direction, the RF front end may include a low-noise amplifier, a mixer, a filter, a switch, etc. If the antenna array 122 is fed as a phased array, the IC chips 160 may include phase shifters effective in the transmission and / or reception paths for phasing the antenna elements 120 relative to each other to dynamically direct the antenna beam. In an example, a single coaxial feedthrough transmission line ("coax feedthrough") 170 may route the input RF signal on the transmission side and / or the combined received signals from all the antenna elements 120 on the reception side. In other cases, two or more coax feedthroughs 170 are provided, and additional separation / combination of the transmit / receive signals is performed at another layer of the antenna device 100, such as by separating / combining the signals going to / from the multiple coax feedthroughs 170. The coax feedthrough 170 is an example of an input / output port of the antenna device 100. It may be replaced with other types of feedthroughs, such as CPW feedthroughs.

[0025] Figure 3A An example of an antenna device 100 configured as a phased array antenna for transmission and reception operations is schematically shown. The antenna device 100 in this example includes N IC chips 1601 to 160 N and (N × k) antenna elements (1201-1 to 1201-k), …, (120 N -1 to 120 N -k), where each chip 160 is connected to k antenna elements 120, and the variables N and k are each two or greater. (However, it should be noted that in some other embodiments, only one antenna element 120 may be connected to each IC chip 160.) In Figure 1 the example, it can be seen that one IC chip 160 is located below four antenna elements 120 (and connected to the four antenna elements), and thus k = 4. Each IC chip 160 i(i = any number from 1 to N) includes k transmit / receive (T / R) circuits 165 i -1 to 165 i -k. Any T / R circuit 165 i -j (j = any number from 1 to k) has one end connected to a corresponding antenna element 120 i -j, and the T / R circuit 165 i -j has its other end connected to a corresponding feed point of the combiner / distributor network 180. In the transmit direction, a transmit RF signal (e.g., provided from a modem) from the feedthrough 170 is split by the combiner / distributor 180 into (N × k) signals, where each separate signal is fed to a separate T / R circuit 165 and modified (e.g., amplified, phase shifted, and / or filtered) by that T / R circuit 165. The modified signal of each T / R circuit 165 is output to the corresponding antenna element 120 to be radiated. In the receive direction, a received signal received by each antenna element 120 is fed through each corresponding T / R circuit 165 and modified (e.g., amplified, filtered, and / or phase shifted). Each modified received signal is output to an input point of the combiner / distributor 180, which combines all the modified received signals and provides the combined received signal to the feedthrough 170.

[0026] Figure 3B An example of the T / R circuit 165 i -j, which can be used for any T / R circuit 165 in the antenna device 100. The T / R circuit 165 i -j may include: a pair of T / R switches 70, 72; a transmit path phase shifter 82; a transmit amplifier 80; a receive amplifier 60, and a receive path phase shifter 62. A control signal CNTRL can be applied to the T / R circuit 165 i -j to control the switching states of the T / R switches 70, 72, and can also dynamically control the phase shifts of the phase shifters 62, 82. During a transmit interval, the T / R switches 70 and 72 are switched to a first switch position to route an incident transmit signal from the combiner / distributor network 180 through the phase shifter 82 and amplifier 80 to the antenna 120 i -j. During a receive interval, the T / R switches 70 and 72 are switched to a second switch position to route an RF received signal from the antenna 120 i -j through the amplifier 60 and phase shifter 62 to the combiner / distributor network 180. The same frequency band or different frequency bands can be used for transmit and receive operations.

[0027] Figure 3B of the T / R circuit 165 i-j is merely an example of a T / R circuit that routes transmit and receive signals between a shared antenna element 120 (shared for processing transmit and receive signals) and a shared combiner / splitter network 180. It may be replaced with other configurations known to those skilled in the art. For example, an alternative T / R circuit may omit the T / R switches 70, 72 and use appropriate isolation mechanisms to utilize different frequency bands for transmit and receive operations respectively to prevent transmit signal power from damaging the receive amplifier 60. The T / R switches 70, 72 may also be omitted by implementing a polarization diversity scheme (e.g., left-hand circular for transmit and right-hand circular for receive, or vice versa).

[0028] Return Figure 2B , shows a cross-sectional view that illustrates an example arrangement and connection technique between any antenna element 120 of the antenna device 100 and the IC chip 160. The IC chip 160 is embedded within the embedded structure 154 and may have signal line contacts 162s and a pair of ground contacts 162g at or near the top surface S1 of the embedded structure 154 for routing RF signals. The conductive vias Vs, Vg formed within the interconnect layer 155 each have respective ends connected to the contacts 162s, 162g and opposite ends having respective contact pads Ps, Pg. During the assembly stage, the antenna subassembly 110 may be attached to the subassembly 150 by attaching the bottom surface of the ground layer 119 to the top surface S2 of the interconnect layer 155. Such attachment may be achieved using an electrically conductive bonding material (e.g., solder) between the corresponding pads on the subassemblies 110, 150 and optionally using an adhesive on other surface areas of the subassemblies 110, 150 to supplement. During this assembly stage, the pad Ps may be soldered to the microstrip probe feed 114 by melting and then cooling the solder balls (or bumps / pillars) 147s during the attachment process. Similarly, a pair of pads Pg may be soldered to the ground layer 119 by a corresponding pair of solder balls 147g, thereby forming a ground-signal-ground (GSG) connection between the feed 114 / ground layer 119 and the signal / ground points of the IC chip 160. The solder balls 147s, 147g may initially be attached to the antenna feed 114 / ground layer 119, as Figure 2B shown, or alternatively attached to the pads Ps, Pg.

[0029] In the illustrated embodiment, when the IC chip 160 is located directly below the antenna element 120, the vias Vs, Vg form a desired short connection between the IC chip 160 and the antenna element 120 contact members. In other embodiments where the IC chip 160 is not located directly below the antenna element 120, GSG connections can be made to points on the coplanar waveguide (CPW) transmission line within the interconnect layer 155. Such CPW transmission lines can have an internal trace extending to a pad Ps and a pair of ground traces (one on each side of the internal trace) extending to a pair of pads Pg, respectively.

[0030] Figure 4 is a cross-sectional view of a portion of the antenna device 100 taken along the Figure 1 IV-IV' path. In this example cross-section, the embedded component subassembly 150 includes an IC chip 160, a transmission line section 180, a coaxial ("coax") feedthrough 170, and a DC via 190. The IC chip 160 can be connected to one or more antenna elements 120 of the subassembly 110 in the manner described above for Figure 2B . After the above attachment phase, an insulating attachment layer 130 can be formed between the subassemblies 110, 150. If an adhesive is applied to supplement the electromechanical attachment of the subassemblies 110, 150 using GSG solder connections, the attachment layer 130 is present; otherwise, the attachment layer 130 can be omitted. In the illustrated example, the one or more RDL layers 155 include a lower RDL layer 155a and an upper RDL layer 155b, where the upper RDL layer 155b separates conductive traces (such as 198, 168, and 188) from the attachment layer 130 / ground layer 119. In an alternative design, the upper RDL layer 155b is omitted such that only the attachment layer 130 separates the ground layer 119 from the conductive traces on top of the RDL layer 155a.

[0031] The IC chip 160, transmission line section 180, and coax feedthrough 170 are each examples of beamforming network components embedded within the molding material (“package”) 152 and may each have an upper surface that is substantially coplanar with the upper surface s1 of the package 152. RDL layer connections between these components may be formed via respective vias V1 that extend from the surface s1 to the upper surface s4 of the RDL layer 155a. Any via (such as V1, Vg, or 190) may have a barrel (e.g., barrel 191 of via 190) that extends through the surrounding dielectric material and a pair of pads on opposite ends, such as P1, P3, Pg, Ps. For example, the IC chip 160 may have a contact 162f connected to via V1, which in turn is connected to a conductive trace 198, another via V1, and a DC via 190. The DC via 190 may extend to the lower surface s3 of the package 152 where its opposite end has a lower pad P3. Conductive traces 198, 168, 188 patterned along the surface s4 may interconnect the beamforming components by connecting to via pads. Any via pads formed on the top surface s1 of the package 152 may be formed before applying the dielectric layer to form the RDL layer 155a. After applying the RDL layer 155a dielectric, the opposite pads of the via may be formed, and then via holes may be drilled through the top pad and extending through the lower pad. The via holes may then be filled with a conductor (e.g., electroplated) to complete via formation.

[0032] Coplanar waveguide (CPW) connections may also be made between the various components via the RDL layer 155 to form interconnects for routing RF signals. For example, the transmission line section 180 may include conductive traces, such as internal CPW traces 182 that extend along the top surface of a low-loss dielectric material 185 (such as quartz or fused silica). The dielectric material 185 is desirably a material having a lower loss tangent than the loss tangent of the package 152. External CPW traces, not shown in Figure 5 but discussed later as Figure 4 trace lines 184a, 184b, may extend parallel to the internal trace 182 on its opposite sides. (In a cross-sectional view of Figure 4 , one CPW external trace may be located in front of the internal trace 182 while the other external trace is located behind the internal trace 182.) One end of the internal trace 182 may be connected to the signal contact 162t of the IC chip 160 via an interconnect formed by an RDL trace 168 between a pair of vias V1. Similarly, a pair of external RDL traces (not shown) may connect the external CPW traces of the transmission line section 180 to a pair of ground contacts ( Figure 4 not shown in Figure 5 but exemplified as contacts 162g in

[0033] The coaxial line 170 is composed of a dielectric 176, such as glass that separates the inner conductor 172 and the outer cylindrical conductor 174. The coaxial line 170 can extend vertically from the surface s1 to the lower surface s3 of the package 152. The inner conductor 172 can be connected to the other end of the inner CPW trace 182 through an interconnect including an RDL trace 188 between a pair of vias V1. The outer conductor 174 can be connected to the outer traces on opposite sides of the inner trace 182 at two points. For example, in Figure 4 the cross-sectional view, a via V2 can be formed behind the inner CPW RDL trace 188. This via V2 can electrically connect a point of the outer conductor 174 to one of the RDL outer CPW traces in the RDL outer CPW traces located behind the inner CPW RDL trace 188. The coax feedthrough 170 and the DC via 190 can each be connected to a surface-mount connector (not shown) at the surface s3. One or more additional IC chips can be mounted to the surface s3 as needed and connected to the IC chip 160 through additional vias. An example of such an additional IC chip is a voltage regulator chip that supplies voltage to the IC chip 160. Another example is a microprocessor chip that supplies control signals to a beamforming circuit system, such as phase shifters and / or T / R switches within the IC chip 160.

[0034] Figure 5 is a plan view of an example embedded component subassembly 150 of the antenna device 100. The subassembly 150 can include IC chips 160 arranged in a planar grid layout. Transmission line segments 180 are disposed in the spaces (“streets”) between some of the IC chips 160. Although the transmission line segments 180 are depicted as a single segment, they can be composed of multiple segments interconnected to each other through interconnects in the RDL layer 155. A gap “g” can separate the edges of the transmission line segments 180 from the adjacent sides of the IC chips 160. In some cases, the minimum gap g size is allocated to account for thermal expansion. It is generally desirable to have a small gap g, but the gap size can be mainly determined by manufacturing constraints. Multiple vias 190 can be disposed adjacent to one or more edges of each IC chip 160. Each via 190 can be connected to the corresponding contact 162f of an adjacent IC chip 160 through an RDL interconnect 198 to route a DC bias signal or a control signal to / from the IC chip 160. For example, the DC bias signal can bias the transmit-direction power amplifier and / or the receive-direction low-noise amplifier (LNA) of the IC chip 160. The control signal can dynamically control the phase of the phase shifter within the IC chip 160.

[0035] The IC chip 160 may have a rectangular profile. At least some of the IC chips in the IC chip 160 may be located directly below portions of a number of antenna elements 120 such that a short connection to the probe feed 114 is achieved through vias. For example, the signal contact 162f of the IC chip 160 may be located directly below a corresponding via in the interconnect layer 155, which in turn is located directly below the probe feed 114. Most portions of each antenna element 120 (e.g., the portion including the probe feed point) may cover a corresponding portion of the IC chip 160. Some of the antenna elements 120 may have most portions covering the corners of the IC chip 160, with a small portion located outside the perimeter of the IC chip 160.

[0036] A coax feedthrough 170 having an inner conductor 172 and an outer conductor 174 may route an input RF signal to some or all of the IC chips 160 via a transmission line section 180. As Figure 4 described, the inner conductor 172 may be connected to the proximal end of the inner CPW trace 182 via an RDL interconnect 188. Additionally, the first CPW outer trace 184a and the second CPW outer trace 184b may be connected to the outer conductor 174 at separate points in the RDL layer 155 via corresponding pads P1 and RDL interconnects 189a, 189b. A splitter network (in transmission) may be formed by splitting the inner CPW trace 182 into multiple paths as Figure 5 shown to separate the signal energy of the RF transmission signal and by providing additional CPW outer traces (such as traces 184c, 184d, and 184e). A power amplifier within each IC chip 160 may amplify portions of the split RF signal before routing to the antenna elements 120. Through appropriate transmit / receive (T / R) switching, the same CPW conductive traces may be used as a combiner network in the receive path to combine RF receive signals received by the antenna elements 120 and amplified by low noise amplifiers (LNAs) within the IC chips 160. The CPW outer traces may each be connected to a ground contact 162g within an adjacent IC chip 160 using RDL interconnects. Similarly, the distal ends of the inner CPW traces 182 may each be connected to a signal contact 162t in a corresponding one of the IC chips in the IC chip 160 (see Figure 4 )

[0037] Figure 6is a flowchart depicting an example method 600 for manufacturing an antenna device 100. Initially, the antenna element subassembly 110 and the embedded component subassembly 150 can be formed separately (block S610). For example, the antenna element subassembly 110 can be formed by first pre-cutting a block of low-loss dielectric 117 (e.g., quartz or fused silica) into the desired profile of the antenna device 100. Then, the lower major surface of the dielectric 117 can be patterned to have a ground layer 119 except for a circular region surrounding the location of each probe feed 114. Then pads for the probe feeds 114 can be formed on the lower surface within this circular region, and via holes can be drilled through the pads. The via holes can then be electroplated to form the probe feeds 114 embodied as vias. Note that the ground layer 119 can be formed either before or after forming the probe feeds 114. Then the antenna element 120 can be formed on the upper major surface of the dielectric 117 by pattern metallization in the region aligned with the location of the probe feeds 114, thereby completing the antenna element subassembly 110. In an alternative sequence, the antenna element 120 is formed before the processes for forming the probe feeds 114 and / or the ground layer 119. The embedded component subassembly 150 can be formed in the manner described below in conjunction with Figure 7 The GSG solder balls can be attached to the GSG contacts of the subassembly 110 or 150.

[0038] Next, the antenna component subassembly 110 can be directly attached (S620) to the embedded component subassembly 150 while concurrently melting and cooling the GSG solder balls to form a GSG interconnect between the two subassemblies, as Figure 2B discussed. (As described above, in some embodiments, the GSG solder connection can serve as the entire mechanical connection without the need for supplementary adhesives.) Then the remaining components can be attached (S630) to the embedded component subassembly 150. These components can include the surface-mount coaxial connectors and DC connectors described above, as well as an IC mounted to the lower surface s3 of the package 152.

[0039] Figure 7 is a flowchart of an example method 700 for forming the embedded component subassembly 150, and Figures 8A - 8G is a cross-sectional view showing the structure corresponding to the respective steps in method 700. In an initial step S710, an adhesive foil 810 (see Figure 8A ) is laminated onto a carrier plate 820, thereby forming a carrier assembly 830. Then the beamforming components can be placed (S720) onto the foil using a pick-and-place tool (see Figure 8B). The beamforming component may include, for example: an IC chip 160; a transmission line section 180 (e.g., a quartz section with or without already formed CPW conductive traces 182, 184); one or more RF feedthroughs, e.g., a coax feedthrough 170; and other IC chips (not shown) having different functions / materials / sizes from the IC chip 160. Some beamforming components (e.g., any of the IC chips in the IC chip 160) may have heat sinks (e.g., Figure 11B the heat sink 1102, discussed later) attached to the beamforming component before being placed on the adhesive foil 810.

[0040] Then, the uncured (liquid or soft) molding material 152 can be applied (S730) to the surface of the adhesive foil around the beamforming component and over the surface of at least some of the beamforming components. Examples of the molding material 152 include epoxy molding compounds, liquid crystal polymers (LCPs), and other plastics such as polyimides. Here, the molding material 152 can be applied with a thickness that is at least the height of the tallest component (e.g., the coax feedthrough 170) relative to the foil surface. Then, the molding material 152 can be cured and optionally trimmed / planarized to form a transition structure with an embedded component structure 154, as Figure 8C depicted. In this way, the embedded component structure 154 can be formed as a wafer-like structure having substantially planar opposing major surfaces s1, s3, and it can also be processed as a wafer.

[0041] In the following step (S740), the carrier 820 and the foil 810 can be removed from the transition structure by debonding from the embedded structure 154 using a debonding tool, and the embedded structure 154 can be flipped, as Figure 8D seen. (Note that in Figure 8D , if the heat sink is attached to the IC chip 160, the thickness of the heat sink may have been preset or trimmed later so that the lower surface of the heat sink is coplanar with the surface s3 of the molding material 152.) Then, pads can be formed (S750) on the opposing surfaces s1 and s3 of the structure 154 at the locations where vias are to be formed or electrical contacts are to be formed for connection to other components. As Figure 8EAs shown, pads P1, Ps, and Pg for forming portions of subsequent vias through the interconnect layer 155 are formed on the top surface s1 by pattern metallization. During this processing stage, if the transmission line section 180 is embedded without the CPW conductive traces 182, 184, the CPW conductive traces can be concurrently formed by pattern metallization when forming the pads P1, Ps, Pg. Portions of vias (such as 190) for forming through the molding material 152 and / or pads P3 for connection to other components can also be formed on the bottom surface s3. Via holes can be drilled through the pads and the molding material 152 and filled with a conductive material (S760) (e.g., by electroplating) to form complete vias (such as 190). Note that as an alternative to providing the coax feedthrough 170 in the form of a single component prior to the embedding process, multiple separate embedded components can be used to form the coax feedthrough at this processing stage.

[0042] One or more RDL layers 155 with vias and interconnects can then be formed over the embedded component structure 154 (S770). For example, in a design having a first RDL layer 155a and a second RDL layer 155b, the first RDL layer 155a can be first formed on the top surface s3 of the embedded structure 154, as Figure 8F shown. Subsequent steps can form a via V1 through the RDL layer 155a, and conductive traces (such as 198, 168, and 188) on the surface s4 of the RDL layer 155a to complete the interconnection between the beamforming components. After that, the second RDL layer 155b can be formed on the top surface s4 of the first RDL layer 155b. Then vias Vg and Vs can be formed that extend through both the first RDL layer 155a and the second RDL layer 155b. In an alternative sequence, the lower portions of each of the vias Vs and Vg can be first formed when the via V1 is formed (i.e., before the second RDL layer 155b is applied). Then the upper portions of the vias Vs and Vg can be formed after the second RDL layer 155b is applied.

[0043] Figure 9Shows a partial layout of another example antenna device 100' according to another embodiment. The antenna device 100' may include an antenna subassembly 110' attached to an embedded component subassembly 150'. The antenna subassembly 110' may have a construction substantially the same as that of the antenna subassembly 110, but with an extended dielectric portion 117 to which an ADC / DAC / processor 910 is attached or embedded. Alternatively, the ADC / DAC / processor 910 is attached to or embedded in an extended portion of the subassembly 150', and the dielectric portion 117 may not extend. The subassembly 150' may include an embedded IC chip 160' and an embedded IC chip 960, which are interconnected with each other through at least one interconnect layer 155 having a construction similar or identical to that described above. The IC chip 960 may have different functions and / or may be made of a different semiconductor material than the IC chip 160'. In an example, the IC chip 160' includes InP transistors (e.g., power amplifiers, low-noise amplifiers, etc.), while the IC chip 960 includes silicon-based or SiGe-based transistors (e.g., beamforming elements such as phase shifters, etc.). The IC chip 160' may include an RF power amplifier and may be directly connected to the antenna element 120 of the antenna subassembly 110' through a via in the at least one interconnect layer 155 in the manner previously described for the IC chip 160. The IC chip 960 may be connected to the antenna element 120 through an extended signal path.

[0044] In one example, the IC chip 960 includes receiver front-end circuitry, such as a low-noise amplifier (LNA), a bandpass filter, a phase shifter, etc., which is connected to the antenna element 120 through conductive traces within the IC chip 160' and / or within the one or more interconnect layers 155. In this case, the receiver circuitry within the given IC chip 960 may modify (e.g., amplify, phase-shift, and / or filter) one or more received signals routed from one or more antenna elements 120 and output the modified received signals to a combiner / distributor network 180' disposed between the IC chip 160' and the IC chip 960. The IC chip 960 may also include or alternatively include a vector generator. An IC chip 970 (e.g., a modem) may also be embedded within the embedded component subassembly 150', and the IC chip may be coupled between the ADC / DAC / processor 910 and the IC chips 960 and 160'.

[0045] Figure 10 Is a flowchart of a method 1000 for manufacturing the embedded component subassembly 150 or 150', where heat sinks are integrated with at least some beamforming components. Figures 11A - 11E Is a cross-sectional view showing a structure corresponding to the respective steps in the method 1000. In the method 1000, an adhesive foil 810 may be laminated (S1010, Figure 11Aonto the carrier 820 to form a carrier assembly 830. Heat sinks can be attached (S1020) to the surface of the selected beamforming components, e.g., in Figure 11B heat sink 1102 is attached to IC chip 160'. The thickness and profile of the heat sink can be selected based on an estimate of the heat generated by the attached beamforming components, their desired operating temperature range, and the heat dissipation characteristics of the heat sink.

[0046] Then the beamforming components (including those with attached heat sinks 1102) can be placed on the surface of the foil 810 (S1030, Figure 11B ). Then a molding material 152 can be applied (S1040, Figure 11C ) around the beamforming components and cured. The molding material 152 can be trimmed as needed to expose the surface of the heat sink 1102, e.g., so that the exposed surface of the fin 1102 is coplanar with the main surface s3 of the molding material 152. If other beamforming components (such as coax feedthroughs 170) are higher than the beamforming components with attached heat sinks (where height is measured from the foil surface 810), the heat sink can be pre-designed to have a certain thickness such that the surface s3 is coplanar with both the exposed surface of the heat sink and the exposed surface of the tallest beamforming component (e.g., 170), as Figure 11C seen. Alternatively, the heat sink and / or the coax feedthrough 170 can be trimmed during a later surface s3 planarization process. Thus, the resulting embedded component structure 154 can be wafer-like with relatively main surfaces that are all substantially flat.

[0047] Subsequently, the carrier and the foil can be debonded from the embedded components and the molding material (S1050), resulting in a wafer-like embedded component structure 154 with opposite surfaces s1 and s3 ( Figure 11D ). One main surface of each beamforming component can be coplanar with the surface s1. Then pads for vias can be formed on the surface s1 and also on the surface s3 (if vias are to be formed through the molding material 152) (S1060). Via holes can be drilled through the pads (S1070) and filled with a conductive material to form vias in the molding material for DC biasing and low-frequency control signals. Then one or more interconnect layers 155 with vias and interconnects can be formed on top of the embedded component structure 154 (S1080), as Figure 11E shown. Note that although not shown in Figures 11A - 11E , vias 190 can be formed in the embedded component subassembly 150' in the same manner as described above for the subassembly 150, and the vias can be connected to the IC chips 160', 960, and / or 970. In Figure 11EIn the example of, the IC chip 160' is electrically connected to the IC chip 960 through an interconnect including signal traces 998 between a pair of vias V1. As in Figures 8A - 8G In the foregoing example of, a single interconnect layer or three or more interconnect layers may replace the pair of RDL layers 155a, 155b in an alternative design example.

[0048] The embodiments of the antenna device as described above can be formed to have a thin profile and can thus be particularly advantageous in constrained space applications. Further, the configuration is adapted to include low-loss elements such as low-loss transmission lines and antenna substrates, which can be particularly beneficial at millimeter-wave frequencies.

[0049] Although the techniques described herein have been particularly shown and described with reference to exemplary embodiments of the techniques described herein, those of ordinary skill in the art should understand that various changes in form and detail may be made therein without departing from the spirit and scope of the claimed subject matter defined by the following claims and their equivalents.

Claims

1. An antenna device (100, 100'), comprising: A first sub - assembly (110, 110'), the first sub - assembly including a plurality of antenna elements (120); And A second sub - assembly (150, 150'), the second sub - assembly being attached to the first sub - assembly, the second sub - assembly including a plurality of components (160, 170, 180) of a beam - forming network encapsulated in a molding material (152), and further including one or more interconnect layers (155) located on the molding material to electrically couple the plurality of components of the beam - forming network to the plurality of antenna elements, Wherein the plurality of components includes an input / output port (170), a combiner / distributor network (180), and a plurality of integrated circuit (IC) chips (160), each of the plurality of IC chips being electrically coupled to at least one of the antenna elements, and wherein: The input / output port routes a transmitted radio - frequency (RF) signal to the combiner / distributor network in a transmission direction, and / or routes a combined received RF signal from the combiner / distributor network in a reception direction; The combiner / distributor network is configured to: split the RF transmission signal into a plurality of separate transmitted RF signals, and / or combine a plurality of modified RF received signals into the combined RF received signal, each of the modified RF received signals being received from one of the IC chips; and Each of the IC chips is configured to: modify a corresponding one of the separate RF transmission signals to provide a modified RF transmission signal, and output the modified RF transmission signal to at least one of the antenna elements coupled to the IC chip; and / or modify an RF received signal provided from at least one of the antenna elements coupled to the IC chip to provide one of the modified RF received signals to the combiner / distributor network.

2. The antenna device (100, 100') according to claim 1, wherein the surfaces of the plurality of components of the beam - forming network are coplanar with the surface of the molding material.

3. The antenna device (100, 100') according to claim 1, wherein the plurality of antenna elements are on a first surface of the first sub - assembly, and the first sub - assembly further includes a via array that is directly connected to the plurality of antenna elements and extends to a second surface of the first sub - assembly, wherein the second sub - assembly is attached to the second surface of the first sub - assembly.

4. The antenna device (100, 100') according to claim 1, wherein the plurality of components includes a plurality of amplifiers (60, 80), the plurality of amplifiers being coupled to the plurality of antenna elements through a plurality of vias (Vs) in the one or more interconnect layers.

5. The antenna device (100, 100’) according to claim 4, wherein an amplifier (60, 80) among the plurality of amplifiers is coupled to a corresponding one of the plurality of antenna elements and is located below the corresponding one of the plurality of antenna elements.

6. The antenna device (100, 100’) according to claim 1, wherein the second subassembly further includes one or more vias (190) that are coupled to the one or more interconnect layers and extend through the molding material to the surface of the second subassembly.

7. The antenna device (100, 100’) according to claim 1, wherein at least one of the components is a transmission line (170) that is coupled to the one or more interconnect layers and extends through the molding material to the surface of the second subassembly.

8. The antenna device (100, 100’) according to claim 1, wherein the first subassembly has a top surface and a bottom surface, the plurality of antenna elements are disposed at the top surface, and the first subassembly further includes a ground layer (119) disposed at the bottom surface.

9. The antenna device (100, 100’) according to claim 1, wherein each of the antenna elements is a patch antenna element having a body that is fed from a point directly below the body by a probe feed perpendicular to a main surface of the body.

10. The antenna device (100, 100’) according to claim 1, wherein the first subassembly and the second subassembly are attached to each other by at least a plurality of ground-signal-ground (GSG) solder connections (147s, 147g), and each of the GSG solder connections electrically connects one of the antenna elements to a signal contact and a ground contact on the one or more interconnect layers.

11. The antenna device (100, 100’) according to claim 1, wherein each of the IC chips includes at least one of (i) a transmit amplifier and / or a transmit phase shifter or (ii) a receive amplifier and / or a receive phase shifter to modify the separate RF transmit signals and / or the RF receive signals provided to the IC chip.

12. The antenna device (100, 100’) according to claim 1, wherein: the input / output port is a coaxial transmission line that extends from a first main surface of the second subassembly to an opposite second main surface of the second subassembly; and the combiner / distributor network is constituted by coplanar waveguides (184a, 184b, 184c) supported by a dielectric (185) disposed between the input / output port and the plurality of IC chips.

13. The antenna device (100, 100’) according to claim 12, wherein the dielectric has a tangent of the loss angle less than that of the molding material.

14. The antenna device (100, 100') according to claim 12, wherein: the dielectric (185) is quartz and the molding material is a liquid crystal polymer; and the first subassembly includes a quartz substrate that supports the plurality of antenna elements.

15. The antenna device (100, 100') according to claim 1, wherein: the component includes a plurality of integrated circuit (IC) chips (160, 160'), the plurality of IC chips are arranged in rows and columns of a two-dimensional array, each IC chip is spaced apart from each other in the row direction and in the column direction, and each IC chip is located directly below at least two probe feeders and is electrically connected to the at least two probe feeders, the at least two probe feeders connect at least two corresponding antenna elements to the corresponding IC chips.

16. The antenna device (100, 100') according to claim 1, wherein the component includes a plurality of integrated circuit (IC) chips (160'), and the second subassembly includes a plurality of heat dissipation fins (1102), each of the heat dissipation fins is attached to a main surface of one of the IC chips.

17. The antenna device (100, 100') according to claim 16, wherein a first main surface of each of the heat dissipation fins is attached to the corresponding IC chip among the IC chips, and an opposite second main surface of the heat dissipation fin is exposed outside the molding material.

18. The antenna device (100, 100') according to claim 1, wherein the beamforming network and the antenna elements are configured to transmit and / or receive signals at millimeter wave frequencies.

19. The antenna device (100, 100') according to claim 1, wherein the plurality of antenna elements includes at least sixteen antenna elements.

20. A method (600) of forming an antenna device, comprising: forming a first subassembly (S610) including a plurality of antenna elements; encapsulating a plurality of beamforming components of a beamforming network in a molding material to form an embedded component structure (S610, 700, 1000); forming one or more interconnect layers (S770) on the embedded component structure, thereby forming a second subassembly; and attaching and electrically connecting the first subassembly to the second subassembly such that the plurality of beamforming components are electrically coupled to the plurality of antenna elements (S620), wherein encapsulating the plurality of beamforming components includes: providing a carrier having an adhesive foil attached to the carrier (S710, S1010); placing the plurality of beamforming components on a surface of the adhesive foil (S720); applying the molding material in an uncured state around the beamforming components when the beamforming components are placed on the adhesive foil surface (S730, S1030); curing the molding material to form a transition structure (S730, S1040); and removing the carrier and the adhesive foil from the transition structure to form the embedded component structure (S740, S1050), The plurality of beamforming components include: a plurality of integrated circuit (IC) chips (160); a combiner / splitter network formed within at least one transmission line section (180); and coaxial feedthrough transmission lines (170), and before applying the molding material, the plurality of IC chips, the combiner / splitter network, and the coaxial feedthrough transmission lines are each placed on the surface of the adhesive foil.

21. The method (600) according to claim 20, wherein attaching and electrically connecting the first sub-component to the second sub-component comprises: Heat and cool a plurality of ground-signal-ground (GSG) solder connections (147s, 147g) between corresponding signal pads (Ps) and corresponding ground pads (Pg) on each of the first subassembly and the second subassembly.

22. The method (600) according to claim 20, wherein forming one or more interconnect layers comprises: Form a plurality of vias (Vs) that pass completely through the one or more interconnect layers for directly electrically connecting at least some of the beamforming components in the beamforming component to corresponding antenna elements in the antenna elements when the first subassembly and the second subassembly are attached to and electrically connected to each other.

23. The method (600) according to claim 20, further comprising: After the molding material is cured, form a plurality of vias through the molding material for subsequent connection to at least one of the IC chips (S760, S1070) in the IC chips through the one or more interconnect layers.

24. The method (600) according to claim 20, further comprising: Before encapsulating the beamforming component, attach heat sinks (1102) to corresponding main surfaces (S1020) of at least some of the beamforming components in the beamforming component.

25. An antenna device (100, 100'), the antenna device is formed by: Form a first subassembly (S610) including a plurality of antenna elements; Encapsulate a plurality of beamforming components of a beamforming network in a molding material to form an embedded component structure (S610, 700, 1000); Form one or more interconnect layers (S770) on the embedded component structure, thereby forming a second subassembly; and Attach and electrically connect the first subassembly to the second subassembly such that the plurality of beamforming components are electrically coupled to the plurality of antenna elements (S620), Wherein the plurality of beamforming components include input / output ports (170), a combiner / splitter network (180), and a plurality of integrated circuit (IC) chips (160, 160'), and each of the IC chips is electrically coupled to at least one of the antenna elements, wherein: The input / output port routes a transmitted radio frequency (RF) signal to the combiner / splitter network in a transmission direction, and / or routes a combined received RF signal from the combiner / splitter network in a reception direction; The combiner / splitter network is configured to: divide the RF transmission signal into a plurality of separate transmitted RF signals, and / or combine a plurality of modified RF received signals into the combined RF received signal, and each of the modified RF received signals is received from one of the IC chips; and Each IC chip in the IC chips is configured to: modify a respective one of the separate RF transmission signals to provide a modified RF transmission signal, and output the modified RF transmission signal to the at least one antenna element coupled to the IC chip; and / or modify an RF reception signal provided from the at least one antenna element coupled to the IC chip to provide one of the modified RF reception signals to the combiner / splitter network, wherein each IC chip in the IC chips includes at least one of (i) a transmission amplifier (80) and / or a transmission phase shifter (82) or (ii) a reception amplifier (60) and / or a reception phase shifter (62) to modify the separate RF transmission signal and / or the RF reception signal provided to the IC chip.

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