CMOS IC and high-gain antenna integration for point-to-point wireless communication

A point-to-point radio communications device, with an integrated antenna-IC module, includes highly-directional antenna elements and silicon CMOS-based ICs in plastic packaging material. The high-gain horn-type antenna includes two sections made of molded plastic and covered in a metallic coating. When combined, the two sections form an aperture and an opening on a face. The face of the antenna element can be mounted directly to an integrated circuit with an antenna coupling element, such that the aperture forms a horn-IC module. The module can be completely enclosed in a plastic-packaging environment using low-cost approach. The antenna-IC module can be manufactured as an integral part of a case for a point-to-point wireless electronic device such as a mobile video phone or a set-top box with tens of gigabits of video downloading capability.

FIELD

The present invention relates generally to highly-directional antenna integration with silicon integrated circuits, and more specifically to millimeter wave high-gain horn antenna integration with CMOS ICs.

BACKGROUND

Current trend in utilizing 57-64 GHz high-data-rate spectrum for wireless communication calls for new, low-cost radios, integrated with set-top boxes or mobile platform/handsets. Energy propagation in this mm-wave band has unique characteristics which enables excellent immunity to interference, highly-secured communication, frequency re-use, etc. For low-cost point-to-point communication at this frequency range, highly directional, high-gain antennas are desired for integration with complementary metal oxide semiconductor (CMOS)-technology-based radios.

Waveguide horn structures are typically used for high gain, directional antennas at millimeter (mm) wave frequencies. Currently available metal horns are bulky, heavy, expensive, and non-ideal for planar, integrated circuit (IC) integration.

DESCRIPTION OF EMBODIMENTS

FIG. 1shows perspective views of horn antenna sections. Horn antenna sections110and140each have an axis shown at116and146, respectively. Horn antenna section110has an interior face112parallel to axis116, and horn antenna section140has an interior face142parallel to axis146.

Horn antenna section110has a notch in interior face112parallel to axis116. The notch in section110has planar faces114. Although the notch in section110is shown with four planar faces, this is not a limitation of the present invention. Any number of planar faces may be included. Horn antenna section140has a notch in interior face142parallel to axis146. The notch in section140has a semicircular cross section144. Other cross-section shapes may be utilized without departing from the scope of the present invention. For example, a cross-section of a notch may have any geometric shape.

The notches in sections110and140may have non-uniform depths. For example, the notch in horn antenna section110may be deeper at end115than at end117. Also for example, the notch in horn antenna section140may be deeper at end145than at end147. As described further below, when two sections with non-uniform depth notches are mated, the notches may form an angular or conical horn aperture.

In some embodiments, sections110and140are made of molded plastic. For example, the sections may be molded in the shape shown, or may be molded with a solid interior face and the notch may be machined. Portions of horn antenna sections110and140may be covered with a conductive material. For example, the notches and inner sides in sections110and140may be covered with a metallic material. In some embodiments, all of sections110and140are covered in a metallic material.

In some embodiments, a horn antenna may be made when two sections are combined such that the interior faces mate, and the notches form an aperture. For example, section120may be identical to section110, and they may be coupled such that their interior faces mate. The notches in sections110and120form an aperture with openings on two ends. An exploded view of an octagonal opening124is shown at end122of the horn antenna formed by sections110and120. Also for example, section150may be identical to section140, and they may be coupled such that their interior faces mate and an aperture is formed with an opening on two ends. An exploded view of a circular opening154is shown at end152of the horn antenna formed by sections140and150.

Apertures in the horn antennas may be diagonal, conical, or any other shape. For example, when the notches in sections110and120have non uniform depths, a diagonal shaped aperture may be formed in the resulting horn radiator. Also for example, when the notches in sections140and150have non-uniform depths, a conical shaped aperture may be formed in the resulting horn antenna.

In some embodiment, only the surface area of the notches are metallized. In these embodiments, the interior surfaces of the aperture are radiative. In other embodiments, the entire antenna radiator sections are metallized. This insures good metal coverage at the joints between reflector sections as well as good electrical connectivity. The ends of the horn may be metallized. For example, ends122and152have metallic coatings to allow the ends to be soldered to an integrated circuit having exposed metal. Various embodiments of horn antenna radiators coupled to CMOS-based integrated circuits are described below with reference toFIG. 3.

FIG. 2shows an integrated circuit to highly directional antenna transition top view and cross section. As an example, top view210and cross sectional view220show metal face212, patch214, and antenna feed line216. Top view210also shows cross slots218in patch214, and cross section view220also shows metal layer224.

Metal face212, patch214, metal layer224, and feed line216are all formed on metal layers within the integrated circuit. As shown in cross section view220, the metal layers are separated by insulating layers. The integrated circuit structure shown inFIG. 2may be manufactured using dielectric and metal layers on top of the CMOS-based silicon IC substrate.

Metal face212is formed in a geometric pattern. Metal face212is shown as octagonal in shape inFIG. 2, but this is not a limitation of the present invention. For example, metal face212may be circular, oval, hexagonal, or any other geometric shape. In general, the geometric pattern of metal face212matches the geometric pattern of a horn antenna radiator opening to which it will be mated, although the various embodiments of the invention also contemplate mating dissimilar shaped metal faces and horn radiator openings.

In operation, feed line216is excited with a signal, and energy radiates through the hole in metal layer224, and through cross-slot218in patch214. A horn antenna may be attached to metal face212, thereby creating a directional antenna-IC module. The dimensions of the various elements in the integrated circuit and the size of the horn may be modified to tune the antenna structure to various frequencies. For example, the elements may be sized to tune the antenna structure to mm-wave frequencies.

FIG. 3shows a combination of CMOS-based silicon integrated circuit and horn antenna that are presented inFIGS. 2 and 1. Integrated circuit220is described above with reference toFIG. 2. Horn antenna310has an aperture312between two ends320and342. End342of horn antenna310is coupled to integrated circuit220such that energy radiated through patch214is directed by aperture312.

Horn antenna radiator310may be attached to integrated circuit220using any suitable method. For example, in some embodiments, end342is metal, face212is metal, and horn antenna310is soldered to integrated circuit220. Also for example, in some embodiments, horn antenna310is glued with a conductive material to CMOS integrated circuit220.

Horn antenna310may be any of the horn antenna embodiments disclosed herein. For example, horn antenna310may be any of the horn antenna made up of sections as shown inFIG. 1. The CMOS IC can be mounted on any plastic materials,355. PCB type plastic boards can be used as355. Section350presents the junction between355and metallized plastic-horn faces,342. Thermal vias,360, may be used, if necessary in the modular assembly.

FIG. 4shows a mobile communications device. Mobile communications device400includes horn antenna320. In some embodiments, horn antenna radiator assemblies370,380,390are manufactured separately from, and then attached to, the different parts of the body of the mobile communications device400. Also in some embodiments, the two pieces of horn antenna320are manufactured as part of two pieces of the body of mobile communications device400. The aperture in horn antenna320is then formed when the body for mobile communications device is assembled. Horn antenna320is coupled to an integrated circuit as shown inFIG. 3. Horn antenna assemblies370,380,390may be mounted at different parts of the mobile communications device, as necessary for the communication.

Mobile communications device400may be any type of device that includes a horn antenna. For example, mobile communications device400may be a mobile video downloading device, mobile phone, a personal digital assistant, a portable music player, or any other mobile communications device. Horn antenna320may be coupled to an antenna used for any type of communications. For example, the antenna may support signal transmission and reception in support of wireless high definition multimedia interface (HDMI), point-to-point personal area networks (WPAN) type of applications.

The antenna-CMOS-IC embodiments may be mounted on a set-top box similar to the mobile device for high-data rate communications, such as, video downloading.