CN103036005B - Projector - Google Patents

Abstract

A projector includes a metamaterial antenna, a signal processing module, and a projector optical system, the metamaterial antenna includes a dielectric substrate and a feed point arranged on a surface of the dielectric substrate, and the feed point is connected to the feed point A connected feeder and a metal structure; the feeder is coupled to the metal structure, the metamaterial antenna receives electromagnetic wave signals containing video and audio information and converts them into electrical signals, and the signal processing module is used to process the electrical signals and generate Resulting information, the projector optics projecting an image in response to the resulting signal. The projector of the present invention uses a built-in metamaterial antenna, which can realize the wireless transmission of high-speed, ultra-broadband, large-capacity video signals to the projector in the above-mentioned wireless manner, which greatly reduces the need for the projector to set various data interfaces. cost.

Description

projector

technical field

The invention relates to projector equipment, in particular to a projector for wireless video and audio access.

Background technique

With the development of various projector technologies, projectors are widely used in various video output display devices. With the various requirements of video transmission, the projector equipment is equipped with various specifications of video and audio input interfaces, such as VGA input interface, USB interface, DVI interface, HDMI interface, RS232 interface and other video and audio input interfaces. Therefore, it is necessary to include various interface data cables in the projector setting accessories, and it is necessary to use wired methods to transmit video and audio signals from various signal sources to the projector. In particular, you can carry a projector with you, also known as a mini projector or a pocket projector. When using these portable projectors, every time a video and audio source (such as a laptop, etc.) is connected to the projector using a wired method, the installation and removal operations are complicated, and the video and audio source is in a wired connection. Greatly restricted.

However, when the above-mentioned wireless transmission of video and audio signals requires not only the fast processing capability of the electronic circuit, but also the requirements for the wireless transmission device-antenna to transmit these video signals at high speed, ultra-wideband, and large capacity, especially high-definition video signals. As the radiating unit and receiving device of the final radio frequency signal, the working characteristics of the antenna will directly affect the working performance of the entire electronic system. However, important indicators such as the size, bandwidth, and gain of the antenna are limited by basic physical principles (gain limit, bandwidth limit, etc. under a fixed size). The basic principle of the limit of these indicators makes the technical difficulty of the built-in antenna far more than that of other devices, and due to the complexity of the electromagnetic field analysis of radio frequency devices, approaching these limit values has become a huge technical challenge.

Contents of the invention

In order to solve the problems existing in existing projectors, the present invention provides a projector for wireless video access, through the application of high-performance metamaterial built-in antenna technology, the built-in antenna can be realized on the premise of meeting the performance requirements of the projector , the present invention adopts the following technical solutions:

A projector includes a metamaterial antenna, a signal processing module, and a projector optical system, the metamaterial antenna includes a dielectric substrate and a feed point arranged on a surface of the dielectric substrate, and the feed point is connected to the feed point A connected feeder and a metal structure; the feeder is coupled to the metal structure, the metamaterial antenna receives electromagnetic wave signals containing video and audio information and converts them into electrical signals, and the signal processing module is used to process the electrical signals and generate Resulting information, the projector optics projecting an image in response to the resulting signal.

Further, the metal structure is formed by engraving a groove topology on a metal sheet.

Further, the metamaterial antenna further includes a grounding unit, which is symmetrically distributed on both sides of the feed point; and several metallized through holes are arranged on the grounding unit.

Further, the metamaterial antenna also includes a reference ground, the reference ground includes a first reference ground unit and a second reference ground unit located on opposite surfaces of the dielectric substrate, the first reference ground unit makes the One end of the feeder line forms a microstrip line.

Further, the first reference ground unit and the second reference ground unit are electrically connected to each other.

Further, the dielectric substrate is provided with several metallized through holes, and the first reference ground unit and the second reference ground unit are electrically connected through the metallized through holes.

Further, the first reference ground unit is provided with a first metal plane unit and a second metal plane unit electrically connected to each other, the first metal plane unit is opposite to one end of the feeder line, so that one end of the feeder line The microstrip line is formed; the second reference ground unit is provided with a third metal plane unit, and the third metal plane unit is opposite to the second metal plane unit.

Further, the dielectric substrate is provided with a plurality of metallized through holes at the second metal surface unit and the third metal surface unit, and the second metal surface unit and the third metal surface unit pass through the Metallized vias for electrical connections.

Further, the second reference ground unit further includes a fourth metal surface unit, the fourth metal surface unit is located on one side of one end of the feeder line, and is located in the extension direction of the feeder line, and the first metal surface unit The unit is electrically connected to the unit on the fourth metal surface through the metallized through hole.

Further, the resonance frequency band of the metamaterial antenna includes at least 2.4GHz-2.49GHz and 5.72GHz-5.85GHz.

Compared with the prior art, the projector of the present invention uses a built-in metamaterial antenna. However, based on the metamaterial antenna technology, a metamaterial antenna designed to resonate electromagnetic waves in one band, two or more different bands determines the volume of the antenna. The physical size of the metal structure is not limited by the physical length of the half-wavelength, and the corresponding antenna can be designed according to the size of the projector itself to meet the needs of miniaturization of wireless communication equipment and built-in antennas. In addition, through the built-in metamaterial antenna, it is possible to wirelessly transmit video and audio signals such as high-speed, ultra-wideband, and large-capacity video signals to the projector through the above-mentioned wireless methods, which greatly reduces the cost of setting various data interfaces for the projector.

Description of drawings

Fig. 1 is the schematic diagram of projector of the present invention;

Fig. 2 is a block diagram of the projector shown in Fig. 1;

3 is a front view of the first embodiment of the antenna in the projector of the present invention;

Fig. 4 is a rear view of the antenna shown in Fig. 3;

Fig. 5 is a simulation diagram of S parameters of the first embodiment of the antenna of the present invention;

Fig. 6 is a front view of the second embodiment of the antenna in the projector of the present invention;

7 is a front view of a third embodiment of the antenna in the projector of the present invention;

Fig. 8 is an enlarged view of the metal structure of the second and third embodiments of the antenna of the present invention;

Fig. 9 is a simulation diagram of S parameters of the first embodiment of the antenna of the present invention;

Figure 10 is a diagram of the far-field simulation results in the E direction when the embodiment 2 of the present invention operates at 2.4, 2.44, and 2.48 GHz;

Fig. 11 is a diagram of the far-field simulation results in the H direction when the embodiment 2 of the present invention operates at 2.4, 2.44, and 2.48 GHz;

Figure 12 is a diagram of the far-field simulation results in the E direction when the embodiment 2 of the present invention operates at 5.725, 5.8, and 5.85 GHz;

Fig. 13 is a diagram of far-field simulation results in the H direction when the embodiment 2 of the present invention operates at 5.725, 5.8, and 5.85 GHz.

detailed description

The projector of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

Please refer to FIG. 1 and FIG. 2 together, which are schematic diagrams and block diagrams of the projector in the present invention. The projector 100 includes a metamaterial antenna 10 , a signal processing module 11 and a projector optical system 12 . The metamaterial antenna 10 receives electromagnetic wave signals containing video and audio information and converts them into electrical signals. The signal processing module 11 is used to process the electrical signals and generate result information. The projector optical system 10 responds to the result signals and projects them into image. In the present invention, the projector 100 includes but not limited to desktop projectors, portable projectors, floor projectors, reflective projectors, transmissive projectors, multifunctional projectors and the like. The wireless input of video and audio signals mentioned above greatly saves the cost of various video interfaces, thereby reducing the cost of the projector.

The antenna in the projector of the present invention is designed based on artificial electromagnetic material technology. Artificial electromagnetic material refers to a topological metal structure that engraves a metal sheet into a specific shape, and the topological metal structure of a specific shape is set at a certain dielectric constant and The performance parameters of the equivalent special electromagnetic materials processed and manufactured on the magnetic permeability substrate mainly depend on the topological metal structure of its subwavelength specific shape. In the resonant frequency band, artificial electromagnetic materials usually exhibit high dispersion characteristics. In other words, the impedance, capacitive inductance, equivalent permittivity and magnetic permeability of the antenna will change drastically with frequency. Therefore, artificial electromagnetic material technology can be used to modify the basic characteristics of the above antenna, so that the metal structure and its attached dielectric substrate equivalently form a highly dispersive special electromagnetic material, thereby realizing a new type of antenna with rich radiation characteristics. The following introduces several implementation methods in the application projector in detail:

first embodiment

Please refer to FIG. 3 and FIG. 4 together. The metamaterial antenna 10 includes a dielectric substrate 1, a metal structure 2, a feeder 3 and reference grounds 41, 42. The dielectric substrate 1 is in the shape of a rectangular plate, which can be made of polymer, Made of materials such as ceramics, ferroelectric materials, ferrite materials or ferromagnetic materials. In this embodiment, the material of the dielectric substrate 1 is made of glass fiber material (FR4), so that not only the cost is low, but also good antenna working characteristics can be maintained at different working frequencies.

The metal structure 2 , the feeder 3 and the reference grounds 41 and 42 are respectively placed on the two opposite surfaces of the dielectric substrate 1 , the metal structure 2 , the feeder 3 and the reference grounds 41 and 42 are formed with the dielectric substrate 1 Metamaterial antenna, the performance of the metamaterial antenna depends on the metal structure 2, in the resonant frequency band, the metamaterial usually exhibits high dispersion characteristics, that is, its impedance, capacitive inductance, equivalent permittivity and magnetic permeability The frequency will change drastically, so by changing the basic characteristics of the metal structure 2 and the dielectric substrate 1, the metal structure 2 and the dielectric substrate 1 are equivalent to form a height according to the Lorentz material resonance model Dispersion of special electromagnetic materials.

Please refer to FIG. 5 , the working frequency bands of the metamaterial antenna in this embodiment are 2.4GHZ˜2.49GHZ and 5.72GHZ˜5.85GHZ, and the gains of the above two frequency bands can reach 3.58dBi and 3.14dBi respectively. It can be understood that the metamaterial antenna 10 can be set to only respond to a frequency band of 2.4GHZ-2.49GHZ, that is, a single-frequency antenna.

The feeder 3 is arranged on one side of the metal structure 2, and extends along the length direction of the metal structure 2, and is coupled with the metal structure 2, wherein, one end of the feeder 3 is bent and extends to One side of the end of the metal structure 2 . In addition, capacitive electronic components can be embedded in the space between the feeder 3 and the metal structure 2 as required, and the signal coupling between the feeder 3 and the metal structure 2 can be adjusted by embedding the capacitive electronic components, according to the formula: It can be seen that the capacitance value is inversely proportional to the square of the operating frequency, so when the required operating frequency is a lower operating frequency, it can be realized by embedding appropriate capacitive electronic components. The capacitance value range of the added capacitive electronic components is usually between 0-2pF, but the embedded capacitance value may also exceed the range of 0-2pF as the operating frequency of the antenna changes.

The reference ground is located at one side of the feeder 3 , so that one end of the feeder 3 at the end of the metal structure 2 forms a microstrip line 31 . In this embodiment, the reference ground includes a first reference ground unit 41 and a second reference ground unit 42, and the first reference ground unit 41 and the second reference ground unit 42 are respectively located on opposite sides of the dielectric substrate 1. surface. The first reference ground unit 41 is provided with a first metal plane unit 411 and a second metal plane unit 412 electrically connected to each other. The second reference ground unit 42 is located on the same side of the dielectric substrate 1 as the feeder 3 , and is provided with a third metal plane unit 421 and a fourth metal plane unit 422 .

The first metal surface unit 411 is opposite to the feeder 3 , so that one end of the feeder 3 at the end of the metal structure 2 forms the microstrip line 31 , that is, the reference ground is a virtual ground. The second metal surface unit 412 is opposite to the third metal surface unit 421 . The third metal surface unit 421 is located at one end of the metal structure 2 , and the third metal surface unit 421 is in the shape of a rectangular plate and extends in the same direction as the feeder 3 . The dielectric substrate 1 is provided with a plurality of metallized through holes 5 at the second metal surface unit 412 and the third metal surface unit 421. The second metal surface unit 412 and the third metal surface unit 421 Electrical connections are made through the metallized vias 5 .

The fourth metal surface unit 422 is located on one side of one end of the feeder 3 and in the extending direction of the feeder 3 . The dielectric substrate 1 is located at the first metal surface unit 411 and the fourth metal surface unit 422 to open a number of metallized through holes 5, the first metal surface unit 411 and the fourth metal surface unit 422 Electrical connections are made through the metallized vias 5 . The microstrip line 31 is formed by the first metal surface unit 411 and one end of the feeder 3, thereby reducing external signal interference to signals transmitted on the feeder 3, improving antenna gain, and achieving better impedance matching. Material saving and low cost. The space between the first metal surface unit 411 and the fourth metal surface unit 422 is ingeniously arranged, so that the reference ground occupies a smaller space and realizes a larger area. In addition, by providing the metallized through hole 5, the area of the reference ground can be further increased.

In summary, the high-gain metamaterial antenna of the present invention obtains the required equivalent permittivity and permeability distribution by precisely controlling the topology of the metal structure 2 and the layout of the microstrip line 31, so that the antenna can work It achieves better impedance matching in the frequency band, completes energy conversion efficiently, and obtains an ideal radiation pattern. It occupies a small volume, has low environmental requirements, high gain, and a wide range of applications. It is suitable for the built-in antenna of the projector.

second embodiment

As shown in FIG. 6 , it is a schematic structural diagram of a metamaterial antenna 10 according to an embodiment of the present invention. The metamaterial antenna 10 in this embodiment includes a dielectric substrate 7 , a feeding point 5 arranged on the dielectric substrate 7 , a feeding line 4 connected to the feeding point 5 , and a planar metal structure 6 . Among them, the feeder 4 and the metal structure 6 are coupled to each other; the metal structure 6 is formed by engraving a slot topology 61 on a metal sheet, and the material corresponding to the slot topology 61 is removed during engraving, and the remaining metal sheet is the metal structure 6. After exiting the topological structure 61 of the slot, metal traces 62 included in the metal structure 6 appear on the metal sheet; the distance between adjacent slots in the topological slot structure 61 is the width of the traces 62, and the width of the topological structure 61 is the same as The widths of the metal traces 62 are equal, and both are 0.15mm; the dielectric substrate 7 can be made of ceramic materials, polymer materials, ferroelectric materials, ferrite materials or ferromagnetic materials, preferably, polymer materials, specifically The ground can be polymer materials such as FR-4 and F4B.

In this embodiment, the metal structure 6 is in the shape of an axisymmetric planar plate. Wherein the metal structure 6 is made of copper or silver. It is preferably copper, which is cheap and has good electrical conductivity. In order to achieve better impedance matching, the metal structure 6 can also be a combination of copper and silver.

Please refer to FIG. 7, which is a front view of the third embodiment of the present invention. The difference between the third embodiment and the second embodiment is that it also includes a grounding unit 8, and a plurality of metallized through holes 81 are arranged on the grounding unit 8; the grounding unit 8 is symmetrical. The two sides of the feeding point 5 are distributed in a uniform manner, and the selection of the dielectric substrate 7 is the same as that of the first embodiment. FIG. 8 is an enlarged view of the metal structures of the second embodiment and the third embodiment. It can be understood that there may be multiple ways of feeding signals between the feeder line 4 and the metal structure 6 . The feeder 4 is directly connected to the metal structure 6 ; and the connection point between the feeder 4 and the metal structure 6 can be located at any position on the metal structure 6 . The feeder 4 is arranged on the periphery of the metal structure 6 in a surrounding manner and the end of the feeder 4 is arranged at any position on the periphery of the metal structure 6 .

This embodiment takes advantage of the characteristics of artificial electromagnetic materials, and adopts the method of engraving a metal structure on a metal sheet, so that the metal structure and the dielectric substrate attached to the metal structure together form an equivalent dielectric constant according to the dispersion of the Lorentz material resonance model. Electromagnetic materials, so as to design antennas with multiple resonant frequency bands. In this embodiment, the antennas shown in the second embodiment and the third embodiment resonate electromagnetic waves in two frequency bands of 2.4GHz-2.49GHz and 5.72GHz-5.85GHz, and the length and width of the metal structure 6 can be adjusted according to the structure of the communication equipment. The layout can be adjusted arbitrarily, but the structural shape of the metal structure 6 can be kept consistent with that in this embodiment. The monopole antenna can be used for single-frequency 2.4GHz-2.49GHz or 5.72GHz-5.85GHz Dual-band 2.4GHz-2.49GHz and 5.72GHz-5.85GHz frequency band communication equipment.

As shown in Figure 9, it is the S-parameter simulation diagram of the second embodiment and the third embodiment of the present invention, which shows that the antennas of the second embodiment and the third embodiment have -15.426dB at 2.4GHz and 5.8018GHz respectively And the loss of -19.184dB, in the 2.4GHz-2.49GHz and 5.72GHz-5.85GHz frequency bands required by the present invention, there is a loss below -10dB, showing that the antenna of the present invention can operate independently at 2.4GHz-2.49GHz or 5.72GHz -Work in the frequency band of 5.85GHz, and can also work in the frequency bands of 2.4GHz-2.49GHz and 5.72GHz-5.85GHz at the same time, and meet the requirements for the metamaterial antenna 10 in the projector.

Fig. 10, Fig. 11, Fig. 12 and Fig. 13 respectively show the second embodiment and the third embodiment of the present invention when the metamaterial antenna 10 operates at 2.4, 2.44, 2.48GHz and 5.725, 5.8, 5.85GHz respectively in the vertical plane (E-Plane) and horizontal plane (H-Plane) direction far-field simulation result diagram, in this result, it can be observed that the polarization effect of the metamaterial antenna of the present invention is no less than that of the existing antenna and meets the application standard.

In the present invention, regarding the processing and manufacturing of the metamaterial antenna 10 , as long as the design principle of the present invention is satisfied, various manufacturing methods can be adopted. The most common method is to use various printed circuit board (PCB) manufacturing methods, such as copper-clad PCB manufacturing, which can meet the processing requirements of the present invention. In addition to this processing method, other processing methods can also be introduced according to actual needs, such as the processing method of conductive silver paste ink, flexible PCB processing of various deformable devices, the processing method of iron sheet antenna, and the processing method of combining iron sheet and PCB. Among them, the combined processing method of iron sheet and PCB refers to the use of precise processing of PCB to complete the processing of slot topology, and use iron sheet to complete other auxiliary parts. Since the metal structure 6 is formed of low-cost copper material, it is easily oxidized when exposed to the air, causing the resonant frequency of the metamaterial antenna 10 to shift or the performance to drop sharply. Therefore, a non-metallic anti-oxidation film is provided on the surface of the monopole antenna . Since the main performance of the present invention is focused on the design of the 6-slot topology 61 of the metal structure, the lead wire of the feeder 4 has relatively little influence on the radiation frequency of the metamaterial antenna 10 . Based on this feature, the monopole antenna can be flexibly placed anywhere in the system, simplifying the complexity of installation and testing.

Embodiments of the present invention have been described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementations, and the above-mentioned specific implementations are only illustrative, rather than restrictive, and those of ordinary skill in the art will Under the enlightenment of the present invention, many forms can also be made without departing from the gist of the present invention and the protection scope of the claims, and these all belong to the protection of the present invention.

Claims (4)

1. A projector, comprising a metamaterial antenna, a signal processing module and a projector optical system, characterized in that, the metamaterial antenna comprises a dielectric substrate and a feeding point arranged on a surface of the dielectric substrate, A feeder connected to the feed point and a metal structure; the feeder is coupled to the metal structure, the metamaterial antenna receives an electromagnetic wave signal containing video and audio information and converts it into an electrical signal, and the signal processing module is used for processing the electrical signal and producing resulting information, the projector optics projecting an image in response to the resulting signal; Wherein, the metamaterial antenna also includes a reference ground located on one side of the feeder line, the reference ground includes a first reference ground unit and a second reference ground unit located on opposite surfaces of the dielectric substrate, the reference ground making one end of the feeder line located at the end of the metal structure form a microstrip line; The first reference ground unit is provided with a first metal surface unit and a second metal surface unit electrically connected to each other, and the first metal surface unit is opposite to one end of the feeder line so that one end of the feeder line forms the Microstrip line; the second reference ground unit is provided with a third metal plane unit, and the third metal plane unit is opposite to the second metal plane unit; the second reference ground unit also includes a fourth metal plane unit, the fourth metal surface unit is located on one side of one end of the feeder line, and is located in the extension direction of the feeder line; the dielectric substrate is provided with a number of metallized through holes, the first reference ground unit and the The second reference ground unit is electrically connected through the metallized through hole. 2 . The projector according to claim 1 , wherein the metal structure is formed by engraving a groove topology on a metal sheet. 3 . 3. The projector according to claim 1, wherein the dielectric substrate is provided with a plurality of metallized through holes at the second metal surface unit and the third metal surface unit, and the second metal surface unit The plane unit is electrically connected to the third metal plane unit through the metallized through hole. 4. The projector according to any one of claims 1-3, wherein the resonant frequency bands of the metamaterial antenna at least include 2.4GHz-2.49GHz and 5.72GHz-5.85GHz.