TWM517431U - Wireless radio frequency antenna structure - Google Patents

Description

Radio frequency antenna structure

The present invention relates to a radio frequency antenna structure, which can set a current path of such a radio frequency antenna originally set to a specific width and a large extension length to a small area, so that the volume occupied by the entire antenna product is greatly reduced.

The planar antenna structure and the operating principle used today mainly include a radiating metal plate and a reflective (grounding) metal plate, and a non-conductive dielectric material is placed between the two metal plates, and at the same time, between the two metal plates. More than one hole is provided to transmit or receive radio frequency signals via conductive metal lines. When the RF signal reaches a desired resonant frequency between the two metal plates, the set RF signal can be transmitted or received.

In the known Micro Strip Antenna (MSA) technology, a common rectangular microstrip antenna (RMSA) or a circular microstrip antenna is included, wherein the width of the rectangular microstrip antenna is generally compatible with the frequency wavelength to enhance the radiation. Capability, but under the same design conditions, the antenna gain that such a microstrip antenna can achieve is small. In the book "Broadband Micro Strip Antenna" by Girich Kumar, it is pointed out that the use of a circular ring microstrip antenna (Annual Ring MSA) can be used to gain the gain of such an antenna, while at the same time enabling the entire Antenna efficiency and radiation efficiency are improved.

Since such wideband microstrip antennas are widely used in various communication products and devices, the antenna itself cannot transmit and receive through a very short period of transient pulse waves, making it There are considerable restrictions on the application. Take Radio Frequency Identification (RFID) as an example. Generally, such a radio frequency identification system transmits identification data by radio waves, and a group of radio frequency identification systems are composed of a reader (Reader) and a radio frequency (Radio Frequency, RF) card (ie, tag TAG), the card reader transmits the frequency to the card by a certain distance, and the preset circuit on the card can be powered back to a coded radio frequency signal to exchange information with the card reader, and the card is read by the card. After the machine performs subsequent processing, it is impossible to transmit and receive the RF signal through the transient pulse wave of a very short period. The result must be operated at a very short distance (almost in the case where the card and the card reader are in close contact with each other). Short-range RFID is not applicable to long-distance systems with large radio signals.

To this end, the Republic of China new patent M472963 "using a phase shifter around The antenna is provided with a hollow slot surrounded by a radiant metal plate, so that the radiant metal plate forms a surface current path with a set width, and a phase shifter is formed inside the current path of the radiant metal plate to achieve a phase shifter. The surface current paths are phase in phase to increase the intensity of the radio signal, and can be applied to longer distance RFID products. However, the surface current path used to form the closed hollow slot is set to a geometric shape such as a circle or a rectangle. In addition to having to be set to a specific width, the overall current path must be set to match the operating frequency wavelength. The extension length and large area make the whole product relatively large, which is not ideal, and there is a need for further improvement.

The purpose of the present invention is to provide a radio frequency antenna structure that can greatly reduce the area of such a radio frequency antenna and relatively reduce the volume occupied by the product.

In order to achieve the above objectives, the present invention comprises a radiant metal on a surface of a substrate. a plate, and a grounded metal plate is assembled on the base by a corner post; the radiating metal plate forms a hollow slot around the closed current path, and a short circuit path is disposed inside the hollow slot, the short circuit path is set Having a feed point, the feed point is connected to the grounded metal plate via a hole preset to the substrate; the current path of the radiant metal plate is matched with the wavelength of the operating frequency as a continuously bent closed line segment, and The current path of such a radio frequency antenna originally set to a specific width and a large extension length can be improved to a smaller area of the meandering bending type.

In a possible embodiment, the current path may be a continuous majority of twists and turns The curved bent closed line segment, the continuous plurality of inverted U-shaped closed line segments or the continuous majority of zigzag closed line segments.

Wherein, each of the curved bending closures constitutes an inner end portion of the line segment and each of the arc-shaped bending closures constitutes an inner top portion of the line segment respectively provided with an open stub, or each inverted U-shaped closed line segment from the inner top Extend the open stub to increase the capacitance of the entire antenna to ground.

In a possible embodiment, the antenna adds one or more sets of ground interference patches externally, and increases the bandwidth of the entire antenna reflection coefficient by single or multiple points of grounding.

10‧‧‧Base

11‧‧‧ hole

12‧‧‧Feeding line

20‧‧‧radiation metal plate

21, 210, 211‧‧‧ current path

22‧‧‧ hollow slots

23‧‧‧ Short circuit path

24‧‧‧Feeding point

25, 26, 250, 260‧ ‧ open road segments

30‧‧‧ corner column

40‧‧‧Grounded metal plate

50‧‧‧Grounding interference film

Fig. 1 is a perspective view showing the first embodiment of the present creation.

Fig. 2 is an exploded perspective view showing the three-dimensional element of Fig. 1.

Fig. 3 shows another embodiment of the reinforcing structure of the radiant metal plate of Fig. 1.

Fig. 4 is a plan view showing a second embodiment of the present radiant metal plate.

Fig. 5 shows another embodiment of the reinforcing structure of the radiant metal plate of Fig. 4.

Fig. 6 is a plan view showing a third embodiment of the present radiant metal plate.

The novelty and other features of the present invention will be apparent from the following detailed description of the embodiments of the drawings.

As shown in Figures 1 and 2, in the illustrated embodiment of the toroidal radio frequency antenna, a desired radiant metal plate 20 is fabricated on a surface of a substrate 10 by etching or the like, and on the substrate 10 A set length of the corner post 30 is assembled to a grounded metal plate 40; the radiating metal plate 20 forms a hollow slot 22 around the closed current path 21, and a short stub is provided inside the hollow slot 22. 23, and a feed point 24 is provided in the short-circuit path 23, and the feed point 24 is connected to the grounded metal plate 40 via a feed line 12 via a hole 11 preset to the substrate 10. The main feature of the present invention is that the current path 21 of the radiant metal plate 20 is matched with the wavelength of the operating frequency as a continuously bent closed line segment. In the first embodiment, the current path 21 is set to be a continuous majority of arcs that are meandering. The shape is formed by bending a closed line segment.

In another embodiment shown in FIG. 3, the inner end portion of each of the arcuately curved closed line segments and the inner top portion of each of the arcuately curved closed line segments are respectively provided with open stubs (open The stubs 25, 26 increase the capacitance of the entire antenna to ground via the characteristics of such open stubs 25, 26. At the same time, in a more desirable embodiment, one or more sets of ground interference patches 50 may be externally added to increase the bandwidth of the entire antenna reflection coefficient by single-point or multi-point grounding.

In the second embodiment of the present invention shown in FIG. 4, the current path 210 is a rectangular or square radio frequency antenna pattern, and the current path 210 is formed by a continuous majority of inverted U-shaped closed line segments. At the same time, when it is extended from one of the constituent sides of the rectangle or the square to the other constituent edge, the area of the entire antenna is reduced by bending at 90°; in another embodiment shown in FIG. 5, each reverse The U-shaped closed line segment extends from the inner top to the open stub 250, 260 to increase the entire The capacitance of the antenna to ground.

In the third embodiment of the present invention shown in Fig. 6, the current path 211 is formed by a continuous majority of zigzag closed line segments that are meandering.

The present invention improves the current path of such a radio frequency antenna to a specific width and a large extension length into a meandering bending type, and can greatly reduce the area (such as 19 cm x 19 cm) by a large area (for example, 10 cm). X10 cm), for ultra-high frequency (UHF) RFID distance measurement, can still read radio frequency (RF) cards (ie, tag TAG) 10 meters away.

The above embodiments are only used to exemplify the present invention, and are not intended to be limiting, and various modifications and modifications may be made to the skilled person in the following claims.

10‧‧‧Base

20‧‧‧radiation metal plate

21‧‧‧ Current path

22‧‧‧ hollow slots

23‧‧‧ Short circuit path

24‧‧‧Feeding point

30‧‧‧ corner column

40‧‧‧Grounded metal plate

Claims (7)

A radio frequency antenna structure includes a radiant metal plate on a surface of a substrate, and a grounded metal plate is assembled on the base by a corner post; the radiant metal plate forms a hollow slot around the closed current path, and a short circuit path is disposed inside the hollow slot, the short circuit path is provided with a feeding point, and the feeding point is connected to the grounding metal plate via a hole preset to the substrate, and is characterized in that: The current path of the radiant metal plate is matched to the wavelength of the operating frequency as a continuously bent closed line segment. The radio frequency antenna structure according to claim 1, wherein the current path is formed by a meandering and more curved curved closed line segment. The radio frequency antenna structure according to claim 2, wherein each of the arc-shaped bent closed end portions of the line segment and the inner top portion of each of the arc-shaped bent closed line segments are respectively provided with an open stub . The radio frequency antenna structure according to claim 1, wherein the current path is formed by a meandering and a plurality of inverted U-shaped closed line segments. The radio frequency antenna structure according to claim 4, wherein the reverse U-shaped closed line segment extends from the inner top portion to the open circuit residual portion. The radio frequency antenna structure of claim 1, wherein the current path is formed by a meandering majority of zigzag closed line segments. The radio frequency antenna structure according to any one of claims 1 to 6, wherein the antenna is externally provided with a ground interference piece, and the single or multi-point grounding is used to increase the bandwidth of the entire antenna reflection coefficient.