Patent Application
20170347490
This invention relates to an antenna for high-frequency, wireless electronic circuits. More particularly, this invention relates a heat dissipating antenna that facilitates heat removal from high-frequency electronic circuits with antennas such as those used for mobile applications.
The power density of high-frequency integrated circuits such as are used in baseband, radio frequency, and power amplifiers is increasing as the geometries in high-frequency integrated circuits such as are used for wireless applications are scaled smaller and smaller. The increased power density results in increased thermal density requiring the attachment of heat spreaders to the wireless chips to dissipate the heat in order to keep the wireless chips operating within a safe thermal range.
Some wireless chips like those used in mobile applications such as 5G wireless communication may generate significant amounts of heat during operation and require the attachment of heat spreaders to dissipate the heat. However, an antenna array may also need to be attached to the wireless chips to broadcast and receive the wireless signals. These antenna arrays may block area to which heat spreaders (heat sinks) may be attached.
In
A magnified cross sectional view of a high frequency integrated circuit 100 with an overlying antenna array 112 is shown in
When a conventional heat spreader 120 (FIG. C) is attached directly to the antenna array 112, the gain (strength of high-frequency wireless signals transmitted from or detected by) of the antenna is severely degraded. A parallel fin copper heat spreader 120 bonded directly to the antenna array 112 reduced the antenna gain by more than 50%. (from about 16 dB to about 7.6 dB at a frequency of 32 GHz).
For this reason, as is illustrated in
A heat dissipating antenna is comprised of a low-attenuating heat spreader bonded to a high frequency antenna or antenna array.
An integrated circuit is comprised of a wireless integrated circuit chip, and a heat dissipating antenna coupled to the wireless integrated circuit chip.
A heat dissipating antenna is formed by forming a low-attenuating heat spreader from dielectric material with high thermal conductivity and bonding it to a high frequency antenna.
Embodiments of the invention are described with reference to the attached figures. The figures are not drawn to scale and they are provided merely to illustrate the invention. Several aspects of the embodiments are described below with reference to example applications for illustration. It should be understood that numerous specific details, relationships, and methods are set forth to provide an understanding of the invention. One skilled in the relevant art, however, will readily recognize that the invention can be practiced without one or more of the specific details or with other methods. In other instances, well-known structures or operations are not shown in detail to avoid obscuring the invention. The embodiments are not limited by the illustrated ordering of acts or events, as some acts may occur in different orders and/or concurrently with other acts or events. Furthermore, not all illustrated acts or events are required to implement a methodology in accordance with the present invention.
The inventors have formed a high frequency antenna with high gain and with high heat dissipation. The inventors discovered that low-attenuating heat spreaders may be created by using dielectric materials with high thermal conductivity. These low-attenuating heat spreaders may be bonded to high frequency antennas or high frequency antenna arrays to form heat dissipating antennas with high gain.
Dielectric materials with high thermal conductivity such as aluminum nitride (AlN), aluminum oxide (Al2O3) and beryllium oxide (BeO) may be formed into a heat spreader that only slightly attenuates antenna gain. Table 1 is a list of aluminum plus several dielectric materials along with their thermal conductivity.
The low-attenuating heat spreader may be manufactured with a variety of designs. Illustrative example designs are portrayed in
The low-attenuating heat spreaders 200, 202, and 204 may be bonded to an antenna array 112 as shown in
Table 2 shows the impact low-attenuating heat spreaders 112 have on the antenna gain of a 16×16 antenna array. The material of the low-attenuating heat spreaders in Table 2 is aluminum nitride. As shown in Table 2 the low-attenuating heat spreaders reduce antenna gain by a few percent in contrast to the conventional metallic heat spreader which reduces antenna gain by more than 50%.
As shown in
As is illustrated in
In step 600 a high-frequency antenna is provided.
In step 602 a low-attenuating heat spreader is formed of a dielectric material with high thermal conductivity such as aluminum nitride, barium oxide, and silicon carbide.
In step 604 the low-attenuating heat spreader is coupled to the front side of the high frequency antenna using a thermally conductive bonding agent such as a thermally conductive epoxy for example.
In step 606 a decision is made if a low-attenuating heat spreader is to be coupled to the front side of the high frequency antenna only or if a low-attenuating heat spreader is also to be coupled to the backside. If a low-attenuating heat spreader is to be coupled to the front side only the flow chart proceeds to step 612 and terminates.
If, however, a second low-attenuating heat spreader is to be coupled to the backside of the high frequency antenna, the flow chart proceeds to step 608 to form a second low-attenuating heat spreader and then to step 610 to attach the second low-attenuating heat spreader to the backside of the high frequency antenna before terminating in step 612.
While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only and not limitation. Numerous changes to the disclosed embodiments can be made in accordance with the disclosure herein without departing from the spirit or scope of the invention. Thus, the breadth and scope of the present invention should not be limited by any of the above described embodiments. Rather, the scope of the invention should be defined in accordance with the following claims and their equivalents.
