Patent Description:
<NUM> of Patent Literature <NUM> and description of a specification related to FIG. <NUM> disclose an antenna having a 3D structure in which a substrate (<NUM>), a high-density, low-speed silicon IC device (<NUM>), an insulating substrate (<NUM>), a low-density, high-speed device (<NUM>), and a substrate (<NUM>) having patch antennas (<NUM>) are stacked on top of each other in this order. The high-density, low-speed silicon IC device has elements (<NUM>) and wiring lines (<NUM>). The low-density, high-speed device has heterojunction bipolar transistors formed thereon.

<CIT> describes a microwave antenna apparatus that comprises a semiconductor package module comprising a mold layer, a semiconductor element, a coupling element and a redistribution layer, and an antenna module mounted on top of the semiconductor package module, said antenna module comprising an antenna substrate, one or more antenna elements, an antenna feed layer and an antenna ground layer. The footprint of the antenna module is larger than the footprint of the semiconductor package module.

<CIT> describes techniques for a patch to couple one or more surface dies to an interposer or motherboard. In an example, the patch can include multiple embedded dies. In an example, a microelectronic device can be formed to include a patch on an interposer, where the patch can include multiple embedded dies and each die can have a different thickness.

<CIT> describes an ultra slim semiconductor package comprising: a multilayer thin film layer including at least one or more dielectric layers and at least one or more redistribution layers; at least one semiconductor chip electrically connected to the redistribution layer and mounted on the multilayer thin film layer; conductive structures electrically connected to the redistribution layer and each formed in a post shape at one side of the multilayer thin film layer; a molding part formed on the multilayer thin film layer and at least partially covering the conductive structures and the semiconductor chip; and bumps for external connection formed on the molding part and electrically connected to the conductive structures.

According to the antenna disclosed in this Patent Literature <NUM>, the area of each compound semiconductor IC chip (<NUM>) arranged at a low density is larger than the area of each of the silicon IC chips (<NUM>) arranged at a high density. Hence, when power is supplied to a silicon wafer (Si wafer) from the substrate having the antennas, it is difficult to provide a feeder that directly connects the substrate having the antennas to the silicon wafer. This necessitates an area for feeding that is provided on the device having the compound semiconductor IC chips mounted thereon, which causes the compound semiconductor IC chips and the Si wafer to share power. Thus, there is a problem that there is a possibility of power supply to the Si wafer becoming unstable due to heat generated upon operation of the compound semiconductor IC chips.

The present disclosure is made to solve a problem such as that described above, and an object of one aspect of embodiments is to provide an active phased array antenna having a 3D structure in which power to an Si wafer is separated from power to compound semiconductor chips.

The above mentioned problems are solved by the antenna according to any of the claims
One aspect of an active phased array antenna of an embodiment is an active phased array antenna including a substrate having a plurality of antenna elements; a pseudo wafer containing a group of semiconductor chips including a plurality of semiconductor chips made of compound semiconductors; and a silicon wafer made of silicon, wherein the silicon wafer includes phase shifters, variable gain amplifiers, and a digital control circuit that control signals of the active phased array antenna; the substrate, the pseudo wafer, and the silicon wafer being stacked on top of each other in this order, and the pseudo wafer includes first feeders to supply power to the group of semiconductor chips from the substrate, wherein each first feeder is a power wiring line; and a second feeder to supply power to the silicon wafer from the substrate, the second feeder passing through the pseudo wafer in a thickness direction of the pseudo wafer, wherein the second feeder is a power wiring line.

Another aspect of an active phased array antenna of an embodiment is an active phased array antenna including a substrate having a plurality of antenna elements formed thereon; a first pseudo wafer containing a first group of semiconductor chips including a plurality of semiconductor chips made of compound semiconductors; a second pseudo wafer containing one or more silicon wafers made of silicon, wherein the one or more silicon wafers includes phase shifters, variable gain amplifiers, and a digital control circuit that control signals of the active phased array antenna; and a third pseudo wafer containing a second group of semiconductor chips including a plurality of semiconductor chips made of compound semiconductors, the substrate, the first pseudo wafer, the second pseudo wafer, and the third pseudo wafer being stacked on top of each other in this order, and the first pseudo wafer includes first feeders to supply power to the first group of semiconductor chips from the substrate, wherein each first feeder is a power wiring line; a second feeder to supply power to the one or more silicon wafers from the substrate, the second feeder passing through the first pseudo wafer in a thickness direction of the first pseudo wafer, wherein the second feeder is a power wiring line; and a third feeder to supply power to the second group of semiconductor chips from the substrate, the third feeder passing through the first pseudo wafer in the thickness direction of the first pseudo wafer, wherein the third feeder is a power wiring line.

According to the above-described one aspect of the active phased array antenna, the pseudo wafer includes the first feeders for supplying power to the group of semiconductor chips from the substrate; and the second feeder for supplying power to the silicon wafer from the substrate, the second feeder passing through the pseudo wafer in the thickness direction of the pseudo wafer. Thus, power to the Si wafer is separated from power to the compound semiconductor chips.

According to the above-described another aspect of the active phased array antenna, the first pseudo wafer includes the first feeders for supplying power to the first group of semiconductor chips from the substrate; the second feeder for supplying power to the silicon wafer from the substrate, the second feeder passing through the first pseudo wafer in the thickness direction of the first pseudo wafer; and the third feeder for supplying power to the second group of semiconductor chips from the substrate, the third feeder passing through the first pseudo wafer in the thickness direction of the first pseudo wafer. Thus, power to the compound semiconductor chips is separated from power to the Si wafer.

Embodiments of the present disclosure will be described below with reference to the accompanying drawings.

With reference to <FIG>, a 3D structured active phased array antenna (APAA) of a first embodiment will be described. First, a configuration of the 3D structured APAA will be described.

<FIG> is a partially cutaway perspective cross-sectional view according to one example of a 3D structured APAA <NUM> of the first embodiment. As shown in <FIG>, the 3D structured APAA <NUM> has a configuration in which a substrate <NUM> having a plurality of antenna elements <NUM>-<NUM> and <NUM>-<NUM> arranged in an array, a pseudo wafer <NUM> that contains a group of semiconductor chips including a plurality of semiconductor chips <NUM>-<NUM> and <NUM>-<NUM> which are made of compound semiconductors, and a silicon (Si) wafer <NUM> made of silicon are stacked on top of each other in this order. The Si wafer <NUM> and the pseudo wafer <NUM> are connected to each other through a first connecting structure group <NUM>. The first connecting structure group <NUM> includes, for example, wiring junctions between metallic wiring lines on the front surface of the Si wafer <NUM>, solder balls, and gold bumps. The pseudo wafer <NUM> and the substrate <NUM> are connected to each other through a second connecting structure group <NUM>. The second connecting structure group <NUM> includes, for example, solder balls and gold bumps. The solder balls and gold bumps do not need to be spherical in shape and may have other shapes. The solder balls and gold bumps may be, for example, cylindrical such as copper posts (copper pillars). An array antenna <NUM> is formed on the underside of the substrate <NUM>. Examples of the array antenna <NUM> include a patch array antenna patterned on the substrate <NUM> and a waveguide slot array antenna having a 3D structure. For one antenna element, one phase shifter is included in the Si wafer <NUM>, and a high power amplifier <NUM> and a low noise amplifier <NUM> are included in the pseudo wafer <NUM>. As such, the 3D structured APAA <NUM> has a configuration of an active phased array antenna having a 3D structure. Each element or component will be described below.

The Si wafer <NUM> is a wafer made of silicon. The Si wafer <NUM> includes phase shifters, variable gain amplifiers (VGAs), and a digital control circuit (not shown) that control signals of the 3D structured APAA <NUM>. Devices such as the phase shifters are provided in the Si wafer <NUM> located on the opposite side of the substrate <NUM> with the pseudo wafer <NUM> interposed, thereby widening the antenna plane of the substrate <NUM>.

The pseudo wafer <NUM> is a pseudo wafer in which the first compound semiconductor chip <NUM>-<NUM> and the second compound semiconductor chip <NUM>-<NUM> are covered with an insulating material. The pseudo wafer <NUM> can be formed using a technology such as fan out wafer level package (FOWLP) or a component-embedded board. Although <FIG> shows only two compound semiconductor chips, the pseudo wafer <NUM> has compound semiconductor chips (not shown) based on the number of antenna elements arranged in an array.

Circuit elements such as transistors are formed on a surface of each of the first compound semiconductor chip <NUM>-<NUM> and the second compound semiconductor chip <NUM>-<NUM> that faces a substrate <NUM> side.

The pseudo wafer <NUM> has a first pseudo wafer pass-through wiring line <NUM>-<NUM>, a second pseudo wafer pass-through wiring line <NUM>-<NUM>, and a third pseudo wafer pass-through wiring line <NUM>-<NUM> as wiring lines that pass through the pseudo wafer <NUM> in the thickness direction. In addition, the pseudo wafer <NUM> has a first via <NUM>-<NUM>, a second via <NUM>-<NUM>, a third via <NUM>-<NUM>, and a fourth via <NUM>-<NUM> as vias that connect the compound semiconductor chips <NUM> in the pseudo wafer <NUM> to terminals provided on the front surface of the pseudo wafer <NUM>. In addition, the pseudo wafer <NUM> has a fifth via <NUM>-<NUM>, a sixth via <NUM>-<NUM>, a seventh via <NUM>-<NUM>, and an eighth via <NUM>-<NUM> as vias that connect the compound semiconductor chips <NUM> in the pseudo wafer <NUM> to terminals provided on the rear surface of the pseudo wafer <NUM>.

The first compound semiconductor chip <NUM>-<NUM> and the second compound semiconductor chip <NUM>-<NUM> are chips made of compound semiconductors such as gallium arsenide (GaAs), gallium nitride (GaN), and indium phosphide (InP). The first compound semiconductor chip <NUM>-<NUM> and the second compound semiconductor chip <NUM>-<NUM> each are structured to have input and output terminals for signals on both of the front surface (a surface on the substrate <NUM> side in <FIG>) thereof and the rear surface (a surface on a Si wafer <NUM> side in <FIG>) thereof. Input and output terminals do not need to be provided on the front and rear surfaces of all compound semiconductor chips. Some input and output terminals on the rear surface of the pseudo wafer <NUM> are connected to the input and output terminals on the rear surfaces of the first compound semiconductor chip <NUM>-<NUM> and the second compound semiconductor chip <NUM>-<NUM>, and some input and output terminals on the substrate <NUM> side of the pseudo wafer <NUM> are connected to the input and output terminals on the front surfaces of the first compound semiconductor chip <NUM>-<NUM> and the second compound semiconductor chip <NUM>-<NUM>.

The first compound semiconductor chip <NUM>-<NUM> and the second compound semiconductor chip <NUM>-<NUM> are the compound semiconductor chips <NUM> of the same structure and have a circuit block such as that shown in <FIG>, for example. As shown in <FIG>, the compound semiconductor chips <NUM> each include a high power amplifier <NUM>, a low noise amplifier <NUM>, an SPDT switch <NUM>, a transmission signal input terminal <NUM>, a transmission and reception signal input and output terminal <NUM>, and a reception signal output terminal <NUM>. An input terminal of the high power amplifier <NUM> is connected to the transmission signal input terminal <NUM>, and an output terminal of the high power amplifier <NUM> is connected to a first terminal of the SPDT switch <NUM>. A second terminal of the SPDT switch <NUM> is connected to the transmission and reception signal input and output terminal <NUM>, and a third terminal of the SPDT switch <NUM> is connected to an input terminal of the low noise amplifier <NUM>. An output terminal of the low noise amplifier is connected to the reception signal output terminal <NUM> of the compound semiconductor chip <NUM>.

Connection of wiring lines from the Si wafer <NUM> to the first compound semiconductor chip <NUM>-<NUM> and the second compound semiconductor chip <NUM>-<NUM> will be described. Power to and control signals for the Si wafer <NUM> are supplied from the substrate <NUM> through the first pseudo wafer pass-through wiring line <NUM>-<NUM>, the second pseudo wafer pass-through wiring line <NUM>-<NUM>, and the third pseudo wafer pass-through wiring line <NUM>-<NUM>. As shown in <FIG>, the pseudo wafer pass-through wiring lines <NUM>-<NUM> to <NUM>-<NUM> pass through the pseudo wafer <NUM> in the thickness direction. Which one of the pseudo wafer pass-through wiring lines supplies power or a signal is determined as appropriate. For example, the first pseudo wafer pass-through wiring line <NUM>-<NUM> supplies power, and the second pseudo wafer pass-through wiring line <NUM>-<NUM> and the third pseudo wafer pass-through wiring line <NUM>-<NUM> supply signals. Power to the first compound semiconductor chip <NUM>-<NUM> is supplied from the substrate <NUM> through the first via <NUM>-<NUM>. Likewise, power to the second compound semiconductor chip <NUM>-<NUM> is supplied from the substrate <NUM> through the third via <NUM>-<NUM>. As such, power to the Si wafer <NUM> and power to the compound semiconductor chips <NUM> are supplied through different lines. Namely, power separation is implemented.

Wiring lines to the first compound semiconductor chip <NUM>-<NUM> and the second compound semiconductor chip <NUM>-<NUM> may be changed as shown in <FIG> is a perspective view showing a configuration of a 3D structured APAA <NUM> which is a variant of the 3D structured APAA <NUM>. In the 3D structured APAA <NUM> of <FIG>, the input and output terminals of the first compound semiconductor chip <NUM>-<NUM> and the second compound semiconductor chip <NUM>-<NUM> contained in the pseudo wafer <NUM> are provided on both of the front and rear surfaces of the first compound semiconductor chip <NUM>-<NUM> and the second compound semiconductor chip <NUM>-<NUM>, but as with the 3D structure APAA <NUM> of <FIG>, the input and output terminals of each compound semiconductor chip <NUM> may be provided only on the front surface (a substrate <NUM> side of <FIG>) of the compound semiconductor chip <NUM> (<NUM>-<NUM>, <NUM>-<NUM>). In this case, the input and output terminals provided on the front surface of the compound semiconductor chip <NUM> (<NUM>-<NUM>, <NUM>-<NUM>) are connected to terminals provided on the rear surface (a surface on an Si wafer <NUM> side in <FIG>) of a pseudo wafer <NUM>, using multilayer redistribution implemented by redistribution using the FOWLP technology and a via structure (vias <NUM>-<NUM> to <NUM>-<NUM>).

In addition, thermal vias <NUM>-<NUM> and <NUM>-<NUM> that thermally connect a surface of the pseudo wafer <NUM> facing the substrate <NUM> to the compound semiconductor chips <NUM> (<NUM>-<NUM>, <NUM>-<NUM>) may be provided in the pseudo wafer <NUM>. The thermal vias <NUM>-<NUM> and <NUM>-<NUM> do not electrically connect the surface of the pseudo wafer <NUM> facing the substrate <NUM> to the compound semiconductor chips <NUM> (<NUM>-<NUM>, <NUM>-<NUM>). The thermal vias <NUM>-<NUM> and <NUM>-<NUM> are vias for heat dissipation and are made of a material with excellent thermal conductivity such as copper. The thermal vias <NUM>-<NUM> and <NUM>-<NUM> can be formed using the FOWLP technology. The high power amplifiers <NUM> included in the first compound semiconductor chip <NUM>-<NUM> and the second compound semiconductor chip <NUM>-<NUM> have high power consumption. By providing the thermal vias <NUM>-<NUM> and <NUM>-<NUM>, heat generated in the first compound semiconductor chip <NUM>-<NUM> and the second compound semiconductor chip <NUM>-<NUM> can be dissipated to the substrate <NUM> serving as a heat dissipator.

The array antenna <NUM> is an array antenna in which antenna elements are arranged in an array or at regular intervals. Examples of the array antenna <NUM> include a patch array antenna patterned on the substrate <NUM> and a waveguide slot array antenna having a 3D structure. Here, with reference to <FIG>, a relationship between the areas of the Si wafer <NUM>, the compound semiconductor chips <NUM>-<NUM> and <NUM>-<NUM>, and the antenna elements <NUM>-<NUM>, <NUM>-<NUM> will be described. <FIG> is a diagram showing an example of a case in which the array antenna <NUM> is formed of a plurality of patch antennas, and showing a relationship between the areas of the Si wafer <NUM>, the compound semiconductor chips <NUM>-<NUM> and <NUM>-<NUM>, and the antenna elements <NUM>-<NUM>, <NUM>-<NUM> as viewed from the front (radiation direction) of the array antenna <NUM>.

As shown in <FIG>, the area of the Si wafer <NUM> is greater than or equal to the sum of the areas of antenna planes of two adjacent elements (<NUM>-<NUM>, <NUM>-<NUM>) among the plurality of antenna elements, and the area of each of the compound semiconductor chips <NUM>-<NUM> and <NUM>-<NUM> is smaller than the area of an antenna plane of a corresponding one of the antenna elements <NUM>-<NUM> and <NUM>-<NUM> among the plurality of antenna elements. By having such a relationship, it is easier to provide a feeder through which power is supplied to the Si wafer <NUM> from the substrate <NUM> separately from feeders through which power is supplied to the compound semiconductor chips <NUM>-<NUM> and <NUM>-<NUM> from the substrate <NUM>.

Next, transmission and reception operations of the 3D structured APAA <NUM> will be described. Upon transmission, transmission signals of the APAA <NUM> generated by the Si wafer <NUM> are inputted to the first compound semiconductor chip <NUM>-<NUM> and the second compound semiconductor chip <NUM>-<NUM> through the fifth via <NUM>-<NUM> and the seventh via <NUM>-<NUM>. The transmission signal inputted to the first compound semiconductor chip <NUM>-<NUM> is inputted to the array antenna <NUM> formed on the substrate <NUM> through the high power amplifier <NUM> and the SPDT switch <NUM> that are contained in the first compound semiconductor chip <NUM>-<NUM>, and the second via <NUM>-<NUM>. On the other hand, the transmission signal inputted to the second compound semiconductor chip <NUM>-<NUM> is inputted to the array antenna <NUM> formed on the substrate <NUM> through the high power amplifier <NUM> and the SPDT switch <NUM> that are contained in the second compound semiconductor chip <NUM>-<NUM>, and the fourth via <NUM>-<NUM>.

Upon reception, reception signals received by the array antenna <NUM> are inputted to the respective first compound semiconductor chip <NUM>-<NUM> and second compound semiconductor chip <NUM>-<NUM> through the second via <NUM>-<NUM> and the fourth via <NUM>-<NUM>. The reception signal inputted to the first compound semiconductor chip <NUM>-<NUM> is amplified by the low noise amplifier <NUM> contained in the first compound semiconductor chip <NUM>-<NUM>, and is inputted to the Si wafer <NUM> through the sixth via <NUM>-<NUM>. On the other hand, the reception signal inputted to the second compound semiconductor chip <NUM>-<NUM> is amplified by the low noise amplifier <NUM> contained in the second compound semiconductor chip <NUM>-<NUM>, and is inputted to the Si wafer <NUM> through the eighth via <NUM>-<NUM>. In the Si wafer <NUM>, a phase difference, amplitudes, etc., of the received signals are processed by a reception circuit contained in the Si wafer <NUM>.

Heat generated in the high power amplifiers <NUM> in the first compound semiconductor chip <NUM>-<NUM> and the second compound semiconductor chip <NUM>-<NUM> is dissipated to the substrate <NUM> through the thermal vias <NUM>-<NUM> and <NUM>-<NUM> as shown by an arrow <NUM> of <FIG>. In addition, vias <NUM>-<NUM> to <NUM>-<NUM> are also in contact with the first compound semiconductor chip <NUM>-<NUM> or the second compound semiconductor chip <NUM>-<NUM> and the substrate <NUM>, and thus, heat generated in the high power amplifiers <NUM> is dissipated to the substrate <NUM> also through the vias <NUM>-<NUM> to <NUM>-<NUM> as shown by the arrow <NUM>.

As described above, the 3D structured APAA <NUM> includes the vias <NUM>-<NUM> and <NUM>-<NUM> for supplying power to the first compound semiconductor chip <NUM>-<NUM> and the second compound semiconductor chip <NUM>-<NUM> from the substrate <NUM>; and the pseudo wafer pass-through wiring lines <NUM>-<NUM> to <NUM>-<NUM> for supplying power to the Si wafer <NUM> from the substrate <NUM>. Namely, power to the compound semiconductor chips <NUM>-<NUM> and <NUM>-<NUM> is separated from power to the Si wafer <NUM>. This prevents the heat generated in the compound semiconductor chips <NUM>-<NUM> and <NUM>-<NUM> from affecting the power to the Si wafer <NUM>, and thus the operations of the 3D structured APAA <NUM> can be more stabilized.

In addition, the area of the Si wafer <NUM> is greater than or equal to the sum of the areas of antenna planes of two adjacent elements among the plurality of antenna elements, and the area of one compound semiconductor chip among a plurality of compound semiconductor chips is smaller than the area of an antenna plane of one antenna element, and thus, it is easier to provide a feeder through which power is supplied to the Si wafer <NUM> from the substrate <NUM> separately from feeders through which power is supplied to the compound semiconductor chips <NUM>-<NUM> and <NUM>-<NUM> from the substrate <NUM>.

Although the first embodiment and the variant thereof show a case in which the pseudo wafer and the silicon wafer each have one layer, either one of the wafers may include a plurality of layers. For example, as shown in <FIG>, a structure may be adopted in which a plurality of pseudo wafers <NUM>-<NUM> and <NUM>-<NUM> are stacked on top of each other. A 3D structured APAA <NUM> of <FIG> includes the plurality of pseudo wafers <NUM>-<NUM> and <NUM>-<NUM> arranged between the Si wafer <NUM> and the substrate <NUM> having antenna elements. The pseudo wafer <NUM>-<NUM> includes, for example, compound semiconductor chips for transmission <NUM>-<NUM> and <NUM>-<NUM> which are made of GaN, etc., and the pseudo wafer <NUM>-<NUM> includes, for example, compound semiconductor chips for reception <NUM>-<NUM> and <NUM>-<NUM> which are made of GaAs, etc. As in the first embodiment, the Si wafer <NUM> includes an analog circuit including VGAs, phase shifters, etc., for radio-frequency signal control.

Alternatively, as shown in <FIG>, a structure may be adopted in which a plurality of silicon wafers <NUM>-<NUM> and <NUM>-<NUM> are stacked on top of each other. In a 3D structured APAA 1MMM of <FIG>, as in the first embodiment, the pseudo wafer <NUM> is a pseudo wafer including the compound semiconductors <NUM>-<NUM> and <NUM>-<NUM>. The silicon wafer <NUM>-<NUM> includes, for example, an analog circuit including VGAs, phase shifters, etc., for radio-frequency signal control. The silicon wafer <NUM>-<NUM> includes, for example, a digital circuit for controlling the silicon wafer <NUM>-<NUM>.

As a still another variant, by combining together a configuration of <FIG> and a configuration of <FIG>, both of the pseudo wafer and the silicon wafer may include a plurality of layers. Note that for easy understanding, in <FIG>, depiction of wiring lines and bumps is omitted.

Next, with reference to <FIG>, <FIG>, and <FIG>, a 3D structured active phased array antenna of a second embodiment will be described. The same elements or components as those included in the 3D structured APAA <NUM> of the first embodiment are given the same numbers and an overlapping description is omitted.

<FIG> is a diagram showing a 3D structured APAA <NUM>-<NUM> according to the second embodiment. The 3D structured APAA <NUM>-<NUM> shown in <FIG> includes a first pseudo wafer <NUM>-<NUM>, a second pseudo wafer <NUM>-<NUM>, a third pseudo wafer <NUM>-<NUM>, a connecting structure group <NUM>-<NUM>, a substrate <NUM>, and an array antenna <NUM>.

The first pseudo wafer <NUM>-<NUM> includes a first GaAs chip <NUM>-<NUM>, a second GaAs chip <NUM>-<NUM>, a third GaAs chip <NUM>-<NUM>, and a fourth GaAs chip <NUM>-<NUM>. The first GaAs chip <NUM>-<NUM>, the second GaAs chip <NUM>-<NUM>, the third GaAs chip <NUM>-<NUM>, and the fourth GaAs chip <NUM>-<NUM> each include the high power amplifier <NUM> and the low noise amplifier <NUM> such as those shown in <FIG>. Note that instead of GaAs chips, compound semiconductor chips such as GaN chips and InP chips may be used.

The second pseudo wafer <NUM>-<NUM> includes a first Si wafer <NUM>-<NUM> and a second Si wafer <NUM>-<NUM>. In the second embodiment, the Si wafers are also formed as pseudo wafers, and power feeders to the third pseudo wafer <NUM>-<NUM> are provided in a resin layer of the second pseudo wafer <NUM>-<NUM>. As in the first embodiment, the area of each of the Si wafers <NUM>-<NUM> and <NUM>-<NUM> contained in the second pseudo wafer <NUM>-<NUM> is greater than the sum of the areas of two adjacent GaAs chips contained in the first pseudo wafer <NUM>-<NUM> (see <FIG>). The first Si wafer <NUM>-<NUM> and the second Si wafer <NUM>-<NUM> each include a control circuit other than a phase shifter, a variable-gain amplifier, and a VCO in a PLL.

The third pseudo wafer <NUM>-<NUM> includes a first signal source GaAs chip <NUM>-<NUM> and a second signal source GaAs chip <NUM>-<NUM>. The first signal source GaAs chip <NUM>-<NUM> and the second signal source GaAs chip <NUM>-<NUM> each include a device such as a voltage controlled oscillator (VCO). Note that instead of GaAs chips, Si chips, GaN chips, InP chips, etc., may be used.

In addition, as described with reference to <FIG>, the pseudo wafers <NUM>-<NUM> to <NUM>-<NUM> or the silicon wafers <NUM>-<NUM> and <NUM>-<NUM> included in the pseudo wafer <NUM>-<NUM> may also be changed in such a manner that any of the wafers includes a plurality of layers as appropriate. For example, the pseudo wafer <NUM>-<NUM> may be changed in such a manner that the pseudo wafer <NUM>-<NUM> includes, as shown in <FIG>, a pseudo wafer having compound semiconductors for transmission and a pseudo wafer having compound semiconductors for reception by providing a plurality of layers in the pseudo wafer <NUM>-<NUM>.

Wiring lines between the substrate <NUM>, the first pseudo wafer <NUM>-<NUM>, the second pseudo wafer <NUM>-<NUM>, and the third pseudo wafer <NUM>-<NUM> will be described.

Power to the first GaAs chip <NUM>-<NUM>, the second GaAs chip <NUM>-<NUM>, the third GaAs chip <NUM>-<NUM>, and the fourth GaAs chip <NUM>-<NUM> included in the first pseudo wafer <NUM>-<NUM> is supplied through respective power wiring lines <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM>. The power wiring lines <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> electrically connect the substrate <NUM> to the GaAs chips <NUM>-<NUM> to <NUM>-<NUM>.

Power to the first Si wafer <NUM>-<NUM> and the second Si wafer <NUM>-<NUM> included in the second pseudo wafer <NUM>-<NUM> is supplied from the substrate <NUM> through a power wiring line <NUM> passing through the first pseudo wafer <NUM>-<NUM>.

Power to the first signal source GaAs chip <NUM>-<NUM> and the second signal source GaAs chip <NUM>-<NUM> included in the third pseudo wafer <NUM>-<NUM> is supplied from the substrate <NUM> through a power wiring line <NUM>-<NUM> passing through the first pseudo wafer <NUM>-<NUM> and the second pseudo wafer <NUM>-<NUM>, and a power wiring line <NUM>-<NUM> in the third pseudo wafer <NUM>-<NUM>.

A radio-frequency signal between the first signal source GaAs chip <NUM>-<NUM> and the first Si wafer <NUM>-<NUM> is supplied through a radio-frequency wiring line <NUM>-<NUM> that connects these elements, and a radio-frequency signal between the second signal source GaAs chip <NUM>-<NUM> and the second Si wafer <NUM>-<NUM> is supplied through a radio-frequency wiring line <NUM>-<NUM> that connects these elements.

A radio-frequency signal between the first Si wafer <NUM>-<NUM> and the first GaAs chip <NUM>-<NUM> is supplied through a radio-frequency wiring line <NUM>-<NUM> that connects these elements, and a radio-frequency signal between the first Si wafer <NUM>-<NUM> and the second GaAs chip <NUM>-<NUM> is supplied through a radio-frequency wiring line <NUM>-<NUM> that connects these elements. In addition, a radio-frequency signal between the second Si wafer <NUM>-<NUM> and the third GaAs chip <NUM>-<NUM> is supplied through a radio-frequency wiring line <NUM>-<NUM> that connects these elements, and a radio-frequency signal between the second Si wafer <NUM>-<NUM> and the fourth GaAs chip <NUM>-<NUM> is supplied through a radio-frequency wiring line <NUM>-<NUM> that connects these elements.

Although in <FIG> the input and output terminals of each of the GaAs chips <NUM>-<NUM> to <NUM>-<NUM> are provided on both of the front and rear surfaces of the chip, as shown in the variant of the first embodiment (<FIG>), the input and output terminals may be arranged only on one surface (front surface) of each chip, and multilayer redistribution may be provided using the FOWLP technology. In this case, the radio-frequency wiring lines <NUM>-<NUM> to <NUM>-<NUM> are routed to the front surfaces of the GaAs chips <NUM>-<NUM> to <NUM>-<NUM> (surfaces of the GaAs chips <NUM>-<NUM> to <NUM>-<NUM> facing antenna elements).

In addition, as in the case of the first embodiment, in the first pseudo wafer <NUM>-<NUM> there may be provided thermal vias <NUM>-<NUM> to <NUM>-<NUM> that thermally connect a surface of the first pseudo wafer <NUM>-<NUM> facing the substrate <NUM> to the GaAs chips <NUM>-<NUM> to <NUM>-<NUM>.

<FIG> shows heat dissipation paths of the 3D structured APAA <NUM>-<NUM> shown in <FIG>. The power consumption of the first GaAs chip <NUM>-<NUM>, the second GaAs chip <NUM>-<NUM>, the third GaAs chip <NUM>-<NUM>, and the fourth GaAs chip <NUM>-<NUM> each including the high power amplifier <NUM> is high. As in the first embodiment, as shown by arrow <NUM>, heat generated in the 3D structured APAA <NUM>-<NUM> is dissipated to the substrate <NUM> through the thermal vias <NUM>-<NUM> to <NUM>-<NUM>. In addition, as in the first embodiment, such heat is dissipated to the substrate <NUM> also through wiring lines between the GaAs chips <NUM>-<NUM> to <NUM>-<NUM> and a surface of the first pseudo wafer <NUM>-<NUM> facing the substrate <NUM> (e.g., the power wiring line <NUM>-<NUM> and wiring lines between the GaAs chips <NUM> and the antenna elements) as shown by the arrow <NUM>.

The 3D structured APAA <NUM>-<NUM> configured in the above-described manner operates in the same manner as the 3D structured APAA <NUM> according to the first embodiment.

As described above, the 3D structured APAA <NUM>-<NUM> includes the power wiring lines <NUM>-<NUM> to <NUM>-<NUM> for supplying power to the GaAs chips <NUM>-<NUM> to <NUM>-<NUM> from the substrate <NUM>; the power wiring line <NUM> for supplying power to the Si wafers <NUM>-<NUM> and <NUM>-<NUM> from the substrate <NUM>, the power wiring line <NUM> passing through the first pseudo wafer <NUM>-<NUM> in the thickness direction; and the power wiring line <NUM>-<NUM> for supplying power to the signal source GaAs chips <NUM>-<NUM> and <NUM>-<NUM> from the substrate <NUM>, the power wiring line <NUM>-<NUM> passing through the second pseudo wafer <NUM>-<NUM> in the thickness direction. Namely, power to the GaAs chips <NUM>-<NUM> to <NUM>-<NUM>, power to the Si wafers <NUM>-<NUM> and <NUM>-<NUM>, and power to the signal source GaAs chips <NUM>-<NUM> and <NUM>-<NUM> are separated from each other.

Hence, power to the first Si wafer <NUM>-<NUM> and the second Si wafer <NUM>-<NUM> contained in the second pseudo wafer <NUM>-<NUM> is fed without passing through the GaAs chips <NUM>-<NUM> to <NUM>-<NUM> contained in the first pseudo wafer <NUM>-<NUM>. Likewise, power to the first signal source GaAs chip <NUM>-<NUM> and the second signal source GaAs chip <NUM>-<NUM> contained in the third pseudo wafer <NUM>-<NUM> is fed without passing through the first GaAs chips <NUM>-<NUM> to <NUM>-<NUM> contained in the first pseudo wafer <NUM>-<NUM> or the first Si wafer <NUM>-<NUM> or the second Si wafer <NUM>-<NUM> contained in the second pseudo wafer <NUM>-<NUM>. Therefore, power used by the signal source GaAs chips <NUM>-<NUM> and <NUM>-<NUM> does not pass through the Si wafers <NUM>-<NUM> and <NUM>-<NUM>. This prevents the heat generated in the GaAs chips <NUM>-<NUM> to <NUM>-<NUM> from affecting the power to the Si wafers <NUM>-<NUM> and <NUM>-<NUM> and the power to the signal source GaAs chips <NUM>-<NUM> and <NUM>-<NUM>, and thus, the operations of the 3D structured APAA <NUM>-<NUM> can be more stabilized.

Some aspects of the embodiments of the present disclosure will be summarized below.

An active phased array antenna (<NUM>; <NUM>) is an active phased array antenna (<NUM>; <NUM>) including a substrate (<NUM>) having a plurality of antenna elements (<NUM>-<NUM>, <NUM>-<NUM>); a pseudo wafer (<NUM>; <NUM>) containing a group of semiconductor chips including a plurality of semiconductor chips (<NUM>-<NUM>, <NUM>-<NUM>; <NUM>-<NUM>, <NUM>-<NUM>) made of compound semiconductors; and a silicon wafer (<NUM>; <NUM>-<NUM>, <NUM>-<NUM>) made of silicon, the substrate, the pseudo wafer, and the silicon wafer being stacked on top of each other in this order, and the pseudo wafer includes first feeders (<NUM>-<NUM>, <NUM>-<NUM>; <NUM>-<NUM>, <NUM>-<NUM>) for supplying power to the group of semiconductor chips from the substrate; and a second feeder (<NUM>-<NUM> to <NUM>-<NUM>; <NUM>-<NUM> to <NUM>-<NUM>) for supplying power to the silicon wafer from the substrate, the second feeder passing through the pseudo wafer in a thickness direction of the pseudo wafer.

An active phased array antenna of additional note <NUM> is the active phased array antenna of additional note <NUM>, and the area of the silicon wafer is greater than or equal to the sum of the areas of antenna planes of two adjacent elements among the plurality of antenna elements, and the area of one semiconductor chip among the plurality of semiconductor chips is smaller than the area of an antenna plane of one antenna element among the plurality of antenna elements.

An active phased array antenna of additional note <NUM> is the active phased array antenna described in additional note <NUM> or <NUM>, and the plurality of semiconductor chips includes a semiconductor chip having input and output terminals (<NUM> to <NUM>) formed on both the front and rear surfaces of the semiconductor chip.

An active phased array antenna of additional note <NUM> is the active phased array antenna described in additional note <NUM> or <NUM>, and the plurality of semiconductor chips includes a semiconductor chip having input and output terminals formed only on one surface of the semiconductor chip, and the pseudo wafer has multilayer redistribution (<NUM>-<NUM> to <NUM>-<NUM>) that connects the input and output terminals of the semiconductor chip to input and output terminals of the silicon wafer.

An active phased array antenna of additional note <NUM> is any one of the active phased array antennas described in additional notes <NUM> to <NUM>, and the pseudo wafer has a thermal via (<NUM>-<NUM>, <NUM>-<NUM>) that thermally connects, instead of electrically connects, a surface of the pseudo wafer facing the substrate to any one of the semiconductor chips included in the group of semiconductor chips.

An active phased array antenna (<NUM>-<NUM>) is an active phased array antenna (<NUM>-<NUM>) including a substrate (<NUM>) having a plurality of antenna elements (<NUM>-<NUM>, <NUM>-<NUM>) formed thereon; a first pseudo wafer (<NUM>-<NUM>) containing a first group of semiconductor chips including a plurality of semiconductor chips (<NUM>-<NUM> to <NUM>-<NUM>) made of compound semiconductors; a second pseudo wafer (<NUM>-<NUM>) containing one or more silicon wafers (<NUM>-<NUM>, <NUM>-<NUM>) made of silicon; and a third pseudo wafer (<NUM>-<NUM>) containing a second group of semiconductor chips including a plurality of semiconductor chips (<NUM>-<NUM>, <NUM>-<NUM>) made of compound semiconductors, the substrate, the first pseudo wafer, the second pseudo wafer, and the third pseudo wafer being stacked on top of each other in this order, and the first pseudo wafer includes first feeders (<NUM>-<NUM> to <NUM>-<NUM>) for supplying power to the first group of semiconductor chips from the substrate; a second feeder (<NUM>) for supplying power to the one or more silicon wafers from the substrate, the second feeder passing through the first pseudo wafer in a thickness direction of the first pseudo wafer; and a third feeder (<NUM>-<NUM>) for supplying power to the second group of semiconductor chips from the substrate, the third feeder passing through the first pseudo wafer in the thickness direction of the first pseudo wafer.

An active phased array antenna of additional note <NUM> is the active phased array antenna described in additional note <NUM>, and the plurality of semiconductor chips includes a semiconductor chip having input and output terminals (<NUM> to <NUM>) formed on both the front and rear surfaces of the semiconductor chip.

An active phased array antenna of additional note <NUM> is the active phased array antenna described in additional note <NUM>, and the plurality of semiconductor chips includes a semiconductor chip having input and output terminals formed only on one surface of the semiconductor chip, and the first pseudo wafer has multilayer redistribution (<NUM>-<NUM> to <NUM>-<NUM>) that connects the input and output terminals of the semiconductor chip to input and output terminals of the silicon wafer.

An active phased array antenna of additional note <NUM> is any one of the active phased array antennas described in additional notes <NUM> to <NUM>, and the first pseudo wafer has a thermal via (<NUM>-<NUM> to <NUM>-<NUM>) that thermally connects, instead of electrically connects, a surface of the first pseudo wafer facing the substrate to any one of the semiconductor chips included in the first group of semiconductor chips.

An active phased array antenna of additional note <NUM> is any one of the active phased array antennas described in additional notes <NUM> to <NUM>, and the third feeder passes through the second pseudo wafer in a thickness direction of the second pseudo wafer.

Note that the embodiments may be combined together or may be modified, and any component may be omitted.

In an active phased array antenna of the present disclosure, power to devices for allowing the active phased array antenna to operate is separated. Thus, the active phased array antenna of the present disclosure can be used as an active phased array antenna whose operations are more stabilized.

Claim 1:
An active phased array antenna (<NUM>, <NUM>) comprising:
a substrate (<NUM>) having a plurality of antenna elements (<NUM>-<NUM>, <NUM>-<NUM>);
a pseudo wafer (<NUM>, <NUM>) containing a group of semiconductor chips including a plurality of semiconductor chips (<NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>) made of compound semiconductors; and
a silicon wafer (<NUM>, <NUM>-<NUM>, <NUM>-<NUM>) made of silicon, wherein the silicon wafer includes phase shifters, variable gain amplifiers, and a digital control circuit that control signals of the active phased array antenna;
the substrate, the pseudo wafer, and the silicon wafer being stacked on top of each other in this order,
wherein the pseudo wafer includes:
first feeders (<NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>) to supply power to the group of semiconductor chips from the substrate, wherein each first feeder is a power wiring line; and
a second feeder (<NUM>-<NUM> to <NUM>-<NUM>, <NUM>-<NUM> to <NUM>-<NUM>) to supply power to the silicon wafer from the substrate, the second feeder passing through the pseudo wafer in a thickness direction of the pseudo wafer, wherein the second feeder is a power wiring line.