TW201711282A - Antenna - Google Patents

Abstract

An array 1 of aligned, coplanar patches 2 of stamped or deposited foil, comprised of rectangles connected serpentine lines 3. Each line comprises short elements 4 extending from their patches towards a neighbouring patch. The short elements extend on the centre line C of the array. Next each line has a transverse short element 5, followed by a semi-circular element 6. These are followed by twice as long not-so-short elements 7 crossing the centreline. A further semi-circular element interconnects these elements on the opposite side of the centreline from the two elements 6. The elements in the lines are coplanar with the patches. An end contact 8 is provided. To form the preferred omni-directional dipole antenna, two such arrays 11, 12 are provided on opposite sides of a dielectric support 14. They are parallel with each other, with the patches of one array positioned between those of the other.

Description

antenna

The present invention relates to an antenna, and particularly, but not exclusively, to an omlinear collinear microstrip antenna for use in systems such as mobile telephone networks, Wifi, Zigbee, and others.

Conventional omnidirectional antennas such as dipoles are limited in gain. To increase gain and maintain true omnidirectionality, one of the drivers is toward collinear antennas.

Collinear antennas have been known for many years. The original concept in the collinear principle of antenna design is described in British Patent No. 242,342, named after Franklin in 1924. It is configured to configure a series of half-wave cables separated by a quarter-wave stub so that each cable is radiated in phase with the outside. This design ensures that the RF energy is radiated omnidirectionally and under a major lobes.

A coaxial collinear antenna has been described by Balsley and Ecklund, "Portable Coaxial Antennas", IEEE Transactions on Antennas and Propagation, vol. 20, 1972, pp. 511-516, ISSN 0018-926X. This system utilizes a series of half-wave coaxial cables and alternates between internal and external. One of these types of earliest microstrip antennas has been described by K. Solbach's "Microstrip-Franklin Antenna", IEEE Transactions on Propagation and Propagation, 1982, Vol. 30, No. 4, pp. 773-775. It describes how a microstrip printed configuration can be utilized to produce an antenna of a Franklin type antenna design that is formed by conductive geometries on opposing substrate layers. Where the inner surface contains electrically conductive components.

Bancroft and Bateman describe a microstrip change in the Balsley and Ecklund antennas in the "omnidirectional planar microstrip antenna", IEEE Transactions on Propagation and Propagation, No. 52, No. 11 of November 2004. Here, the patches are alternately staggered on both sides of a single substrate. In these designs, it is advantageous to have an interval between the patches close to a multiple of λg/2, where λg is the wavelength in the microstrip trace. For microstrips, this wavelength λg is dependent on the dielectric material chosen, and to a lesser extent depending on the geometry of the microstrip.

There are two problems with the design of this antenna. First, the length of the straight trace must be about λg/2, which is determined by the dielectric constant and geometry of the microstrip. This means that the patch length must be the same. Secondly, the dielectric substrate absorbs the power that would otherwise be radiated, thus reducing the gain of the antenna.

This first problem can be solved according to our invention, which is solved by the introduction of a meandering trace that is longer than the straight trace. This can be made to be a multiple of λg/2, and the patch length can be changed by changing the 蜿蜒. This allows the patch length to be selected to optimize the performance of the antenna. The file can be square, sinusoidal, triangular, or any other form.

This second problem can be mitigated by a preferred feature of our invention, which is mitigated by the use of low loss materials such as RT Duroid, but these materials can be expensive. In a preferred feature of our invention, another solution to this problem is to use an inverted microstrip. In the inverted microstrip, most of the electric field is contained in the low loss gap, and the loss is greatly reduced. This system enables cheaper substrate materials and processes Used to be used in high frequency antennas.

By utilizing inverted microstrips, the fields are mostly in air, which means that the loss is low and the wavelength is closer to the wavelength in the air. Under a straight trace, this will result in a patch length of almost half the wavelength. In order to optimize antenna performance in terms of gain, bandwidth, and reflection loss, a patch length of about 1/4 of a wavelength in air is desirable. This can be achieved by twisting the line.

It is an object of the invention to provide an improved antenna.

According to the present invention, there is provided an antenna comprising an array of a plurality of aligned patches, the adjacent patches being interconnected by non-linear lines, the configuration being such that The distance of one of the lines between the two of the patches is greater than their physical spacing.

In other words, the antenna system includes a plurality of dimensionally separated patch elements interconnected by a meandering trace. The tortuous routing allows the patch length to be independent of the patch spacing. This allows for a patch length that is optimized for the performance of the antenna. Although the patches may be formed three-dimensionally, such as having a cylindrical shape that is aligned, such as a cylindrical shape, in the preferred embodiment they are planar and coplanar.

The patches may have curved edges. Preferably, however, they have straight edges. Likewise, the corners between the edges may be curved, but are preferably angled. In a preferred embodiment, the patches are rectangular.

The wires may be irregularly shaped, having straight or curved elements. The elements may be connected angularly or in a curved manner. However, these components are preferred They are interconnected smoothly, as if they were in a shape. In the preferred embodiment, the shape of the crucible is formed by semi-circular elements joined by short linear elements in a vertically aligned direction. A smooth alternative will be a sinusoidal shape. Preferably, the elements extend over a centerline of the patches or extend to both sides of the centerline.

In a preferred embodiment, the non-linear lines have a length along the patch therebetween that is substantially equal to a half wavelength of the electromagnetic propagation therein or an integer multiple of a half wavelength, and The physical spacing of the patches and their length between the non-linear lines is substantially one quarter of the wavelength.

Although the antenna may be constructed from an array of single aligned patches, it is preferably constructed of a pair of aligned arrays, one of which is attached to the patch in another array. The gap between them is opposite.

The patches can be supported on opposite sides of a dielectric constant support. Alternatively, the two arrays can be supported on the facing side of two such supports separated by a gap. Preferably, the gap is an air gap or is occupied by a low loss dielectric material, typically a foam material.

Preferably, the dielectric constant support is a resin or ceramic material having a polymeric reinforcement, and the patches or wires are metal deposition or lamination.

1‧‧‧Array

2‧‧‧SMD

3‧‧‧蜿蜒的线

4‧‧‧Short components

5‧‧‧Horizontal short components

6‧‧‧ semi-circular components

7‧‧‧Two times longer and not too short components

8‧‧‧Terminal point

11, 12‧‧‧ array

14‧‧‧Dielectric support

21, 22‧‧‧ array

23, 24‧‧‧Support (dielectric substrate)

C‧‧‧ center line

To assist in the understanding of the present invention, two specific embodiments thereof will now be described by way of example and with reference to the accompanying drawings in which: FIG. 1 is a patch of an array of an antenna for use in the present invention. Plan view, FIG. 2 is a similar view of the array of FIG. 1 with overlapping intervals in a similar array In the above, Figure 3 is an end view of two overlapping arrays on opposite sides of a single support in an embodiment, and Figure 4 is supported on the facing side of two spaced apart supports A similar end view of two overlapping arrays.

Referring to Figure 1, an array of aligned coplanar patches 2 having stamped or deposited foils includes a line 3 of rectangularly connected turns. Each of the wires includes a short element 4 extending from its patch toward an adjacent patch. The short elements extend over the centerline C of the array. Next, each of the wires has a laterally short element 5 followed by a semi-circular element 6. These are followed by twice as long and not too short elements 7 that traverse the centerline. The other semi-circular element interconnects the elements from the two elements 6 on opposite sides of the centerline. The components in the lines are coplanar with the patches. One end contact 8 is set.

To form a preferred omnidirectional dipole antenna, as shown in FIG. 3, two such arrays 11, 12 are disposed on opposite sides of a dielectric support 14. They are parallel to each other with an array of patches disposed between those patches of another array.

The patches have a length of substantially 1/4 of the wavelength of electromagnetic waves to be propagated in the air from the direction of the centerline. They are separated by the same distance, plus a tolerance for the length of the short elements, whereby each patch is opposite the entirety of the semi-circular elements. The length of the lines along their range is substantially 1/2 of the wavelength.

In an alternative embodiment of FIG. 4, the two arrays 21, 22 are disposed on the facing sides of the two supports 23, 24. The gap between them can be, for example, a foamed poly Styrene foam material is occupied to control its spacing.

In other words, in a first embodiment of the invention, the single substrate is geometrically conductive on both sides. The geometries include radiating elements, such as patches that are joined together by microstrip routing. The patches are arranged on both sides of the substrate such that they are staggered as shown in FIG. The microstrip trace uses a ground plane that is a patch on the other side of the substrate. The electrical length of the microstrip trace needs to be an integer multiple of about 1/2 wavelength. The actual physical length of the microstrip trace is fixed by the selected dielectric constant and geometric electrical characteristics, which can be evaluated by any person skilled in the art. The optimum length and spacing of the patch for antenna performance is mostly different from the physical length of the microstrip. In order to match the length of the microstrip and the patch spacing, the microstrip traces are meandering. The file can be sinusoidal, square, triangular or other pattern.

In a second embodiment of the invention, as shown in Figure 4, the antenna is configured with an inverted microstrip comprising two facing dielectric substrates 23 and 24 separated by a gap. The gap can be air or a low loss dielectric. As shown in Figure 4, the substrates have a conductive geometry on the inner surface. The geometry consists of, for example, radiating elements of the patch that are joined together by microstrip routing. The patches are disposed on the two substrates such that they are interlaced with each other, but unlike the first embodiment, the patches are separated by separating the gaps of the two substrates. The microstrip trace uses a ground plane that is a facing patch on another substrate such that the microstrip is placed across the two substrates. Most of the field of the microstrip is contained within the gap, which is air, or a very low loss of dielectric, thus reducing losses in the microstrip.

In these designs, a pair of substantially 1/4 λ patch elements determines the electrical connection. The length of the network of interleaved or adjacent patches is a factor defined by 1/4 λ, so the required length is essentially 1/2 λ. In the present invention, the interlaced pattern of elements is combined with a microstrip configuration, and the present invention additionally includes an optimum 1/2 λ electrical phase match by utilizing a meandering trace to extend the electrical length.

In this first embodiment, the introduction of the traces of the turns allows the electrical length to be independent of the component spacing. This improves antenna performance in terms of gain and bandwidth, and also allows for a wider variety of materials that may not be considered. In this second embodiment, the introduction of the inverted microstrip is an improvement in the antenna design of a single substrate in which most of the RF field is located in the substrate that absorbs energy. This allows a wider variety of substrates to be selected, which may have higher losses, but may be less expensive to manufacture.

The present invention is progressive over typical two omnidirectional microstrip antennas having two conductive geometries on either side of a dielectric substrate. Typical conductive geometries are made up of patches or components that are separated by straight traces as in the design of Bancroft or Bateman. In the present invention, the separate straight traces are replaced by a tortuous trace. This produces many advantages as previously described. A second advancement is the use of inverted microstrips to reduce antenna losses, which yields the previously described advantages.

Preferably, the electrical length of the microstrip patch geometry is 1/4 λ of the center frequency of the desired operating band, and the trace is 1/2 λ. The tortuous traces may be under or over the patches on the alternating layers, which maintains the characteristics of the microstrip.

The present invention can incorporate patches having different electrical lengths to increase the resulting operating frequency band in the resulting antenna.

1‧‧‧Array

2‧‧‧SMD

3‧‧‧蜿蜒的线

4‧‧‧Short components

5‧‧‧Horizontal short components

6‧‧‧ semi-circular components

7‧‧‧Two times longer and not too short components

8‧‧‧Terminal point

C‧‧‧ center line

Claims (23)

An antenna comprising an array of a plurality of aligned patches, the adjacent patches being interconnected by non-linear lines, the configuration being such that along between the two of the patches The distance of one of the lines is greater than its physical spacing. The antenna of claim 1, wherein the antenna comprises a plurality of patch elements, and the adjacent patch elements are interconnected by a meandering trace, whereby the meandering trace allows the sticker The length of the patch is independent of the patch spacing. An antenna according to claim 1 or 2, wherein the patches are three-dimensionally shaped, for example, having an aligned cylindrical shape, such as a cyclic cylindrical shape. An antenna according to claim 3, wherein the patches have an aligned cylindrical shape, preferably a cyclic cylindrical shape. An antenna according to claim 1 or 2, wherein the patches are planar and preferably coplanar. The antenna of claim 5, wherein the patches have curved edges. The antenna of claim 5, wherein the patches have straight edges, wherein the corners between the edges are curved or angled. The antenna of claim 7, wherein the patches are rectangular. An antenna according to claim 1, wherein the non-linear wires are irregularly shaped, and have straight or curved members. The antenna of claim 1, wherein the non-linear wires are regularly formed, having straight or curved elements. Such as the antenna of claim 9 or 10, wherein the elements are angularly Or connect them in a curved way. An antenna according to claim 10, wherein the elements are smoothly interconnected, preferably interconnected in a meandering shape. An antenna according to claim 12, wherein the shape of the crucible is constituted by a semicircular element connected by a short linear element perpendicular to the aligned direction. An antenna according to claim 12, wherein the shape of the crucible is a sinusoidal shape. The antenna of claim 2, wherein the components extend on a centerline of the patches or extend to both sides of the centerline. An antenna according to claim 1 or 2, wherein the non-linear lines have a length along the patch therebetween, substantially equal to a half wavelength of electromagnetic propagation therein or An integer multiple of a half wavelength, and the physical spacing of the patches and their length between the non-linear lines is substantially one quarter of the wavelength. An antenna according to claim 1 or 2, wherein the antenna is formed by a single aligned array of patches. An antenna according to claim 1, wherein the antenna is formed by a pair of aligned arrays, wherein an array of patches is opposite the gap between the patches in the other array. The antenna of claim 18, wherein the patches of the aligned array of the pair are supported on opposite sides of a dielectric constant support. An antenna according to claim 18, wherein the patches of the aligned array of the pair are supported on the facing sides of the two dielectric constant supports separated by a gap. Such as the antenna of claim 19 or 20, wherein the dielectric constants are supported The struts are resin or ceramic materials having polymerization strengthening, and the patches or wires are metal deposition or lamination. An antenna according to claim 20, wherein the gap is an air gap or is occupied by a low loss dielectric material, usually a foam material. For example, the antenna of claim 1 or 2, wherein the antenna is an omnidirectional collinear antenna.