KR101239963B1 - Complex antenna - Google Patents

Abstract

A composite antenna capable of coping with both circular and linear polarizations is disclosed.

The disclosed composite antenna includes a substrate; A feed terminal provided on one side of the substrate; Four helical antenna elements disposed on the substrate at intervals of 90 degrees about a first axis perpendicular to the substrate; Four delay lines of differing lengths of the quarter wavelength; And four switch modules connected to the power supply terminals in common and connected to each helical antenna element and one delay line. Here, the switch module is a first mode for directly connecting the feed terminal and each helical antenna element, the delay line is applied to each helical antenna element so that the feed phase after being fed from the feed terminal and propagating the delay line sequentially shifts by 90 degrees. Any one of the second modes of connection can be selected.

Description

Complex antenna

1 is a schematic perspective view of a composite antenna according to a first embodiment of the present invention.

2 is a schematic diagram showing an antenna feeding network of the present invention.

3A is a schematic diagram showing the state of the switch module in the case of linear polarization.

3B is a schematic diagram showing the state of the switch module in the case of circular polarization.

4 is a schematic plan view showing a layout design of a PCB of an antenna feeding network.

5 is a schematic perspective view of a PCB.

6 is a schematic perspective view of a second embodiment of the present invention.

7 is a schematic perspective view of a third embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

20,22,24,26 ... first to fourth switch module

30, 32, 34, 36 ... first to fourth delay lines

40, 42, 44, 46 ... first to fourth helical antenna elements

48 ... PCB

50 ... cylindrical dielectric

52. Support

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite antenna, and more particularly, to a composite antenna capable of coping with both circular and linear polarizations.

Portable wireless devices are required to be able to communicate using a satellite such as a global positioning system (GPS) as well as a telephone or a personal data assistant (PDA). For example, there is a lot of safety benefits if you can emergencyly contact the police or fire department through the cell phone base station with accurate location information obtained using GPS satellites. In addition, satellite radios using broadcast satellites are expected to be rapidly spread because they have good sound quality, have many channels, and can cover a large area.

The above applications require an antenna capable of both terrestrial and satellite communications.

Since GPS and satellite radio are circular piers, patch antennas and four-wire helical antennas are used. On the other hand, since a mobile telephone, a wireless LAN, or the like is a straight knitting machine, a monopole antenna or the like is used.

Thus, the technique of the antenna which can respond to both a circular polarization and a linear polarization is disclosed by Unexamined-Japanese-Patent No. 2002-314312. According to this disclosed technique, a monopole antenna is arranged in the vicinity of the central axis of a four-wire helical antenna, and the four-wire helical antenna and the monopole antenna each correspond to circular polarization and linear polarization. However, this is an integration of other structural antennas, such as a helical antenna and a monopole antenna, and the miniaturization effect due to the complex is insufficient.

The present invention has been made based on the recognition of such a problem, and an object thereof is to provide a composite antenna capable of coping with both circular and linear polarizations.

In order to achieve the above object, a composite antenna according to the present invention, a substrate; A feed terminal provided on one side of the substrate; Four helical antenna elements disposed on the substrate at 90 degree intervals about a first axis perpendicular to the substrate; Four delay lines of differing lengths of the quarter wavelength; And four switch modules connected to the feed terminals in common and connected to the helical antenna elements and the delay lines, respectively, wherein the switch module directly connects the feed terminal and each helical antenna element. To select one of the first mode and a second mode of connecting the delay line to each helical antenna element so that the power supply phase after being fed from the power supply terminal and propagated to the delay line is sequentially shifted by 90 degrees. It is characterized by one.

Hereinafter, a composite antenna according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic perspective view showing main parts of a composite antenna according to a first exemplary embodiment of the present invention.

The composite antenna of the present embodiment includes a printed circuit board (PCB) 48, a feed terminal P0, first to fourth helical antenna elements 40, 42, 44, 46, and first to The fourth switch module 20, 22, 24, 26 and the first to fourth delay lines 30, 32, 34, 36 are provided.

Each of the helical antenna elements 40, 42, 44, 46 is made of a conductor and extends toward the ceiling in a spiral shape with a pitch angle in the range of, for example, 30 to 60 degrees. These first to fourth helical antenna elements 40, 42, 44, 46 are disposed on the PCB 48 at intervals of 90 degrees concentrically, respectively. In addition, four switch modules 20, 22, 24, and 26 and four delay lines 30, 32, 34, and 36 are arranged on the PCB 48. The first to fourth switch modules 20, 22, 24, and 26 control the connection with the first to fourth delay lines 30, 32, 34, and 36.

The outer diameter, length, pitch angle, and the like of the spirals of the helical antenna elements 40, 42, 44, 46 directly affect the characteristics such as the radiation pattern and the gain of the antenna, and can be appropriately designed according to the requirements. As a material of the helical antenna elements 40, 42, 44, 46, a good conductor such as aluminum or a copper alloy may be used.

An antenna feed network constituting an electrical circuit between each helical antenna element 40, 42, 44, 46 and the feed terminal P0 is provided on the substrate 48. The switch modules 20, 22, 24, and 26 for controlling the connection with each of the delay lines 30, 32, 34, and 36 are arranged on an antenna feed network.

The antenna feeding network is preferably provided on the PCB 48. Therefore, the PCB 48 is preferably set to such a size that all the antenna feeding networks can be installed, and the diameter of the PCB 48 is one times the outer diameter of the spiral of the helical antenna elements 40, 42, 44, 46. More preferably, it is within the range of 3 times.

2 is a schematic diagram showing the configuration of an antenna feeding network.

In the antenna feed network, a switch module 20 is provided between each helical antenna element 40, 42, 44, 46 and a feed terminal P0 to control a connection with each delay line 30, 32, 34, 36. 22. 24, 26) are arranged.

The power supply terminal P0 is connected to a power supply unit (not shown) to input a driving power. The line length of the first delay line 30 is referred to as L1. The line length L2 of the second delay line 32 is L1 + λ / 4, the line length L3 of the third delay line 34 is 'L2 + λ / 4', and the line length L4 of the fourth delay line is 'L3 + λ'. / 4 'is set respectively. Here, lambda is the wavelength on the delay lines 30, 32, 34, 36 of the electromagnetic wave transmitted through the delay lines 30, 32, 34, 36.

In the antenna feeding network, first to fourth antenna terminals P1, P2, P3, and P4 are provided to be connected to the helical antenna elements 40, 42, 44, and 46. The first to fourth antenna terminals P1, P2, P3, and P4 are connected to arms of the helical antenna elements 40, 42, 44, and 46. As a result, the feeding phases of the first to fourth helical antenna elements 40, 42, 44, 46 fed via the respective delay lines 30, 32, 34, 36 are sequentially delayed by 90 degrees. As the delay lines 30, 32, 34, and 36, micro strip lines may be used.

3A and 3B are schematic diagrams showing the switching states of the switch modules 20, 22, 24 and 26. FIG.

The switch modules 20, 22, 24, and 26 are provided with first to fourth switch terminals A, B, C, and D, and are switched as shown in FIGS. 3A and 3B.

For example, the first switch terminal A is connected to the power supply terminal P0 by wiring on the PCB 48. The second switch terminal B is connected to each antenna terminal P1, P2, P3, P4 by wiring on the PCB 48, and then to each helical antenna element 40, 42, 44, 46. The third switch terminal C is connected to one end of each delay line 30, 32, 34, 36, and the fourth switch terminal D is the other of each delay line 30, 32, 34, 36. It is connected to the end.

In the case of transmitting and receiving linear polarization, as shown in FIG. 3A, the circuits to the delay lines 30, 32, 34, and 36 are opened, so that all four helical antenna elements 40, 42, 44, and 46 are in phase. do.

On the other hand, in the case of transmitting and receiving circular polarization (including reception only), the phase at each helical antenna element is shifted by 90 degrees. In terms of the lengths of the delay lines 30, 32, 34, and 36, the lengths of the delay lines 30, 32, 34, and 36 are increased by a quarter wavelength in the order from the first antenna terminal P1 to the second antenna terminal P4. At this time, the switch modules 20, 22, 24, and 26 are switched as shown in FIG. 3B to connect the feed terminal P0 side with one end of each of the delay lines 30, 32, 34, and 36. As shown in FIG. Similarly, in order to connect the first to fourth antenna terminals P1, P2, P3, and P4 to the other ends of the delay lines, the switch modules 20, 22, 24, and 26 are switched as shown in FIG. 3 (b). . As the switch modules 20, 22, 24, and 26, for example, a semiconductor device having a PIN structure can be used.

Table 1 shows the feed phases of the first to fourth antenna terminals P1, P2, P3, and P4 for the case of linear polarization and circular polarization, respectively. In linear polarization driving, all of the first to fourth antenna terminals P1, P2, P3, and P4 are in the same phase α (degrees). On the other hand, in the case of circular polarization driving, if the phase of the first antenna terminal P1 is β (degrees), β + 90 (degrees) at the second antenna terminal P2 and β + 180 at the third antenna terminal P3. (Fig. 4), the fourth antenna terminal P4 is at β + 270 (Fig.). In all cases, the amplitude is the same.

Feeding condition Feed phase (degrees) P1 P2 P3 P4 When driving linear polarization alpha alpha alpha alpha When driving circularly polarized wave β β + 90 β + 180 β + 270

In addition, when high precision is not required in amplitude and phase, the 1st switch module 20 and the 1st delay line 30 can be abbreviate | omitted. Even in this case, in the present specification, it is assumed that there is a first delay line 30 having a zero line length, and a first switch module 20 which is always connected to the feed terminal P0 and the first antenna terminal P1. . In addition, when high precision is required for amplitude, an amplitude adjusting attenuator can be added to the delay lines 30, 32, 34, 36.

Next, the layout of the PCB 48 will be described in more detail.

4 is a schematic plan view showing the layout of the PCB 48.

The feed terminal PO is arranged near the center of the PCB 48. The first to fourth antenna terminals P1, P2, P3, and P4 are disposed at an angle of about 90 degrees on a concentric circle with respect to the feed terminal P0.

The first switch module 20 is disposed in the middle of the first to fourth antenna terminals P1, P2, P3, and P4, and the first switch terminal A includes a feed terminal P0 and a second switch terminal ( B), the first antenna terminal P1, the third switch terminal C, one end of the first delay line 30, and the fourth switch terminal D, the other end of the first delay line 30. And are respectively connected. If the delay lines 30, 32, 34, 36 can be connected to the third switch terminal C and the fourth switch terminal D, the arrangement is not limited to this figure. Hereinafter, the second switch module 22, the third switch module 24, and the fourth switch module 26 are similarly disposed.

5 is a schematic perspective view of the PCB 48. The helical antenna elements 40, 42, 44, and 46 are connected to the first to fourth antenna terminals P1, P2, P3, and P4 of the PCB 48 so as to face the ceiling in a spiral shape, respectively. Configure the same composite antenna. Such an arrangement design of the PCB 48 can make the circuit area less than half than that of a general T-type divider and a delay line, and therefore, the antenna can be miniaturized.

In addition, the feed terminal P0 is connected to a circular polarization using wireless system and a linear polarization using wireless system through a splitter and a switch. If the front end portion is disposed on the back surface of the PCB 48 (that is, the antenna feeding network), the composite antenna can be further miniaturized.

The composite antenna of the present invention as described above uses a helical antenna element for circular polarization and linear polarization. As a result, it is not necessary to provide a monopole antenna separately, and even if the size is the same as that of a conventional four-arm helical antenna, it can cope with both circular polarization and linear polarization, so that miniaturization as a composite antenna can be realized. Furthermore, by having one feed terminal (i.e., antenna input / output port) as indicated by reference numeral P0 in Fig. 1, the connection with the front end of the wireless system can be simplified, and the composite antenna can be further miniaturized. .

The helical antenna element illustrated in FIG. 1 may be composed of a thin plate-shaped conductor. The helical antenna element is more preferably a good conductor, and is not limited to the thin plate shape. In order to further increase the mechanical strength, a structure in which a conductor is wound around the cylindrical dielectric 50 is preferable.

6 is a schematic perspective view of a composite antenna according to a second embodiment.

For example, the conductor is wound around the cylindrical dielectric 50 with a pitch angle in the range of 30 to 60 degrees. The cylindrical dielectric 50 is fixed to the PCB 48 to increase the mechanical strength of the helical antenna elements 40, 42, 44, 46. In this case, as described later, if the groove is formed in advance on the surface of the cylindrical dielectric 50, the helical antenna elements 40, 42, 44, 46 can be more easily fixed.

On the other hand, as shown in Figure 4 switch module (20, 22. 24, 26) is disposed between the feed terminal (P0) and the first to fourth antenna terminals (P1, P2, P3, P4), the dielectric ( Since the circumferential end of 50 is placed adjacent to the first to fourth antenna terminals P1, P2, P3, and P4, the switch modules 20, 22. 24, 26 are accommodated in the dielectric 50.

Fig. 7 is a schematic perspective view showing the third embodiment. The helical antenna elements 40, 42, 44, 46 are wound in a spiral shape on the support 52 standing on the PCB 48. The support 52 is formed of an insulator in a mesh shape. At this time, the pattern of the reticular is not limited to the pattern shown in FIG. The overall skeleton of the support 52 is cylindrical. By supporting the helical antenna elements 40, 42, 44, 46 by using the support 52, a composite antenna having a light weight and improved mechanical strength can be constructed. The switch modules 20, 22, 24, and 26 are disposed on the feed terminal (P0 in FIG. 4) and the first to fourth antenna terminals P1, P2, P3, and P4 in the same manner as in the above-described embodiment, and the support Since the circumferential end of 52 is placed adjacent to the first to fourth antenna terminals P1, P2, P3, and P4, the switch modules 20, 22, 24, and 26 are accommodated inside the support 52. do.

According to the embodiments described above, by switching the connection of the four-wire helical antenna element by the switch module, it is possible to select whether the feeding phase of the four-wire helical antenna element is the same or shifted by 90 degrees. In the same phase, linear polarization for terrestrial communication can be transmitted and received. On the other hand, by shifting the phase by 90 degrees, the circular polarization for satellite communication can be received (or transmitted and received).

In the above, embodiment of this invention was described, referring drawings. However, the present invention is not limited to these examples. For example, a person having ordinary knowledge in the field of size, shape, arrangement, material, etc. of components such as an antenna element, a switch module, a delay line, a cylindrical dielectric, a support, and a PCB constituting a composite antenna. Various design changes are included in the present invention without departing from the gist of the present invention.

As described above, the composite antenna according to the present invention has a structure capable of coping with both circular polarization and linear polarization, and is suitable for linear polarization and circular polarization simply by switching four helical antenna elements by four switch modules. Because it can be shared, it can be miniaturized.

Such a composite antenna of the present invention has been described with reference to the embodiments shown in the drawings for clarity, but this is merely exemplary, and various modifications and equivalent other embodiments are possible to those skilled in the art. I will understand the point. Accordingly, the true scope of the present invention should be determined by the appended claims.

Claims (12)

Board; A feed terminal provided on one side of the substrate; Four helical antenna elements disposed on the substrate at 90 degree intervals about a first axis perpendicular to the substrate; Four delay lines of differing lengths of the quarter wavelength; And Four switch modules connected to the feed terminals in common and connected to each of the helical antenna elements and one of the delay lines; The switch module includes a first mode for directly connecting the power supply terminal and each helical antenna element, and each helical antenna element so that the power supply phase after being fed from the power supply terminal and propagated to the delay line is sequentially shifted by 90 degrees. Select one of the second modes of connecting the delay line to Transmit or receive linear polarization in the first mode, transmit or receive circular polarization in the second mode, The switch module includes a first switch terminal connected to the feed terminal; A second switch terminal connected to each helical antenna element; A third switch terminal connected to one end of each delay line; And a fourth switch terminal connected to the other end of each delay line, wherein the first switch terminal and the second switch terminal are connected in the first mode, and the first switch terminal is connected to the first switch terminal in the second mode. While the third switch terminal is connected and the second switch terminal and the fourth switch terminal are connected, The delay line is provided on the substrate, The switch module is provided on the substrate, And the diameter of the substrate is in a range of 1 to 3 times the outer diameter of the spiral of the helical antenna element. delete delete delete delete The method of claim 1, It further comprises a cylindrical dielectric, And said helical antenna element is wound in a spiral shape on said dielectric. The method of claim 6, And the switch module is accommodated in the dielectric. The method of claim 1, Further provided with a cylindrical mesh support formed of an insulator, And the helical antenna element is wound around the mesh support. 9. The method of claim 8, The switch module is a complex antenna, characterized in that accommodated inside the mesh support. The method of claim 1, The helical antenna element is a composite antenna, characterized in that the thin plate-shaped conductor. The method of claim 1, An attenuator is connected to at least one delay line. delete

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