JPH06140835A - Circular polarized antenna shared for transmission and reception - Google Patents

Abstract

PURPOSE:To make the antenna compact and thin and to easily make it into an array by integrating the transmission/reception shared antenna, which is provided with satisfactory circular polarized characteristics in the respective bands of transmission and reception and enables high-level separation between transmission and reception, up to a feeding circuit. CONSTITUTION:A patch 5 for transmission is operated as a patch antenna regarding a patch 3 for reception as a ground conductor and corresponding to the shape, circular polarized waves are generated. The patch 3 for reception is operated as a patch antenna, and radio waves received at points Q1 and Q2 are turned to components for which polarized waves are made orthogonal each other. These two outputs are synthesized with phase difference at 90 deg. and the same amplitude and received as circular polarized waves. Concerning the transmission antenna, the band is narrow since circular polarized waves are generated by feeding at one point P. Concerning the reception antenna, the band is wider than that of the transmission antenna since circular polarized waves are generated by feeding at two points Q1 and Q2 and a 90 deg. hybrid coupler or a Wilkinson power distributor is used. Namely, a coupling amount is small in the transmission frequency band although two antennas are coupled in the reception frequency band.

Description

Detailed Description of the Invention

[Object of the Invention]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dual polarized antenna for transmitting and receiving, capable of transmitting and receiving simultaneously.

[0003]

2. Description of the Related Art An antenna mounted on a mobile unit used for satellite mobile communication is required to be small, thin, and lightweight, capable of transmitting and receiving at the same time, and operating in circular polarization. As a configuration of such an antenna in the related art, a transmission / reception common antenna as shown in FIG. 9 having a common transmission / reception input / output port and a transmission / reception input / output port as shown in FIG. 10 are separately provided. There is a duplex antenna provided.

The antenna element shown in FIG. 9 requires a wideband transmission / reception shared antenna 91 capable of covering the transmission and reception frequency bands. In this case, a non-exciting radiating element is provided on the radiating element. It is possible to widen the band of the planar antenna by using such a method. However, in the method of FIG. 9, the demultiplexer 92 is important for separating the transmission and reception radio waves. In particular, in order to prevent the transmission power having a very large output from leaking to the receiver side, it is necessary to realize a high degree of separation in transmission and reception, and the bandpass filter forming the demultiplexer 92 is large and complicated. Become. Therefore, the antenna as a whole has a large and complicated structure. On the other hand, in the system of FIG. 10, the antennas are separately configured by the transmitting antenna 100 and the receiving antenna 101, so that the antenna has a certain degree of separation between transmission and reception, and the band pass filters 102 and 103 for transmission and reception separation.
Is characterized by being small and easily realized. Figure 1
As the antenna of 0, if the main purpose is separation of transmission and reception, the transmission antenna 100 and the reception antenna 101 may be provided at completely different places. However, providing two separate antennas increases the size of the antenna system. Considering mounting on a moving body such as an automobile, the place where the antenna can be installed is limited, so there are many inconveniences in terms of shape, weight, cost, etc., if the antennas are constructed separately.

From the above, as a mobile communication antenna, the transmitting and receiving antennas are integrated, but the transmitting and receiving input / output ports exist separately, and a certain degree of isolation between the transmitting and receiving is achieved. What is required is required. As such an antenna, various methods have been proposed for those that have opposite polarizations when transmitting and receiving, but the number of antennas that have circular polarization and the same polarization when transmitting and receiving is the same. Few. As one of the few examples, FIG. 11 shows a transmission / reception shared antenna that uses a ring antenna as a reception antenna. Here, FIG. 11A is a top view of the transmitting / receiving shared antenna, and FIG. 11B is a cross-sectional view taken along the line AA ′ of FIG. 11A.

The ring antenna, which is a receiving antenna, is composed of a ground conductor 110 and a ring-shaped conductor 111. The transmitting antenna above the receiving antenna is a circular patch antenna, and the circular conductor 112 serves as a radiator, and the ring-shaped conductor 111 is regarded as a ground conductor to operate. The circular conductor 112 has the ground conductor 110 at the center point O.
Are connected by a conductor 113, and generation of unnecessary higher-order modes in the transmission antenna is suppressed. The transmitting antenna is fed at points f1 and f2, and the receiving antenna is fed at points F1 and F2, respectively, to create a circularly polarized wave. At the two feeding points of transmission and reception, power is fed with the same amplitude and a relative phase difference of 90 degrees. Further, the ring-shaped conductor 111 and the ground conductor 110 are connected using a conductor 114 having a cylindrical surface so that the power feeding of the transmission antenna does not affect the reception antenna. This shared antenna for transmission and reception realizes excellent circular polarization characteristics in transmission and reception, and can achieve a large degree of isolation between transmission and reception by using a hybrid coupler or the like at the feeding point.

[0007]

However, the above-described conventional transmitting / receiving circularly polarized antenna has the following problems. First, the ring antenna is larger than the circular patch antenna, and the entire antenna is large, which is difficult to manufacture and is not suitable for arraying. In particular, it becomes difficult to arrange the elements at an element interval that does not generate a grating lobe when arrayed. Although the size of the antenna element can be reduced by using a dielectric having a high dielectric constant, in this case, the power loss due to the dielectric becomes a problem. Second, the ring-shaped conductor 111 and the ground conductor 110
Since it is necessary to connect the gaps using the conductor 114 having a cylindrical surface shape, it cannot be configured only by stacking dielectric substrates having conductor films etched. Thirdly, it is a method of feeding power by directly connecting the center conductor of the coaxial line, and it is difficult to match the antenna. Fourth, it is difficult to form a power supply circuit such as a power distributor or a hybrid coupler integrally with the antenna in a planar circuit.

The present invention has been made in order to solve the above-mentioned conventional problems, and has a good circular polarization characteristic in each band of transmission and reception and realizes a high degree of separation between transmission and reception. It is an object of the present invention to provide a dual polarized antenna for both transmission and reception, which can be integrated into a power feeding circuit, which can be made compact and thin, and which can be relatively easily manufactured and easily arrayed. To do.

[Constitution of Invention]

[0010]

A circular polarized wave antenna for both transmission and reception of the present invention, which achieves the above object, is a plane type reception antenna which is fed to two feeding points with a relative phase difference of 90 degrees. And a plane type transmission antenna which is located above the type reception antenna and which is fed at one feeding point and radiates circularly polarized waves. At the two feeding points of the plane type receiving antenna, a resistor is formed of a conductor. Connect a power distributor connected to a part of the output antenna to separate the output port of radio waves received by the planar receiving antenna from the input port of radio waves to be transmitted by the planar transmitting antenna, and to perform transmission and reception at the same time. It features a circular polarization antenna for both transmission and reception.

In the circular polarized wave antenna for both transmission and reception according to a second aspect of the invention, an array antenna is formed by using the transmission and reception shared antenna composed of the planar type reception antenna and the planar type transmission antenna as an element, and the adjacent elements are arranged on a horizontal plane. It is characterized in that it is rotated by a certain angle within and arranged in a positional relationship of parallel movement.

[0012]

According to the present invention, both the transmitting antenna and the receiving antenna can be constituted by the planar patch antenna, and they can be integrated to be small and thin. The transmitting antenna can realize good circular polarization characteristics in the transmitting frequency band. The reception antenna can realize good circular polarization characteristics in the reception frequency band. Here, a 3-dB hybrid coupler or a Wilkinson type power divider with the same distribution ratio is used to feed power at two points, so the receiving antenna has circular polarization characteristics over a wide band including the transmission frequency band and It is possible to prevent leakage of radio waves from the antenna.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of a circular polarization antenna for both transmission and reception according to the present invention. The dual-use circularly polarized antenna for transmission and reception is configured by stacking a ground conductor 1 and dielectric films 2 and 4 in parallel. Between the ground conductor 1 and the dielectric film 2 and between the dielectric film 2 and the dielectric film 4, any one of air, a dielectric substrate, a paper honeycomb, or the like, which is considered to be equivalent to air or a dielectric, is used. Or intervene. A reception patch 3 formed of a conductive film is formed on the surface of the dielectric film 2, and a transmission patch 5 formed of a conductive film is formed on the surface of the dielectric film 4, respectively. The receiving patch 3 and the transmitting patch 5 can be easily formed by an etching technique. When a dielectric substrate is used under the patch, a patch directly etched on the surface of the dielectric substrate can be used.

The transmitting patch 5 has a shape in which a pair of diagonal portions of a square are cut, and a point P which is a feeding point.
At, the central conductor 6 of the coaxial line 7 is connected by a method such as soldering. The outer conductor of the coaxial line 7 is connected to the receiving patch 3. With such a configuration, the transmitting patch 5 operates as a patch antenna that regards the receiving patch 3 as a ground conductor. At this time, the degenerate mode is separated due to the shape of the transmitting patch 5, and circularly polarized waves are generated.
The transmitting patch 5 needs to be smaller than the receiving patch 3 so that the transmitting patch 5 does not affect the receiving antenna. This can be achieved relatively easily when the transmission frequency and the reception frequency are relatively far apart and the transmission frequency is higher than the reception frequency. Even if the transmission frequency and the reception frequency are close to each other or the transmission frequency is lower than the reception frequency, a dielectric having a higher dielectric constant than that used in the reception antenna is provided between the transmission patch 5 and the reception patch 3. By using the body substrate, the transmitting patch 5
Can be made smaller. The operating frequency and axial ratio of the transmitting antenna can be easily adjusted by changing the size of the transmitting patch 5 and the size of the cut. Further, impedance matching can be performed by changing the position of the feeding point P.

The receiving patch 3 has a square shape, and the point Q is rotated by 90 degrees with respect to the center of the patch.
1 and Q2 are connected to the central conductors 8 and 9 of the coaxial lines 10 and 11, respectively. Both outer conductors of the coaxial lines 10 and 11 are connected to the ground conductor 1. With this configuration,
The receiving patch 3 operates as a patch antenna. Here, the radio waves received at the points Q1 and Q2 are components whose polarizations are orthogonal to each other, and the two outputs are received as circularly polarized waves by combining them with the same amplitude with a phase difference of 90 degrees. Become. As a means for combining with the same amplitude with a phase difference of 90 degrees, a 3 dB 90 degree hybrid coupler or Wilkinson type power divider (actually, a power combiner should be used, but the configuration and operation are the same for transmission and reception). Therefore, the following description will be made regardless of transmission / reception) and a 90-degree phase shifter. The operating frequency of the receiving antenna can be adjusted by changing the size of the receiving patch 3, and impedance matching can be performed at the feeding points Q1 and Q1.
It can be done by changing the position of 2. Although the coaxial line 7 vertically penetrates a part of the receiving antenna, the number of the coaxial line 7 is only one, which is very thin, and the influence on the receiving antenna is small. At this time, by passing the coaxial line 7 vertically through the center of the receiving patch 3, it is possible to completely eliminate the influence on the generation of the fundamental mode for the receiving antenna to operate as an antenna. Furthermore, in this case, by connecting the outer conductor of the coaxial line 7 to the ground conductor 1,
There is an advantage that it is possible to suppress the generation of unnecessary higher-order modes that adversely affect the radiation directivity of the antenna.

With the above structure, an antenna having good circular polarization characteristics for transmission and reception can be realized, and the antenna can be manufactured small and thin. At this time, by making the transmitting patch 5 sufficiently smaller than the receiving patch 3, the transmitting and receiving antennas do not affect each other's characteristics, and the transmitting and receiving antennas can be designed almost independently. convenient. Further, it can be simply constructed by simply stacking the dielectric substrate or the like in which the conductor pattern is etched, and the electrical connection between the upper and lower substrates is only the feeder line.

Next, the degree of separation between the transmission port and the reception port will be described. In the configuration shown in FIG. 1, since the circularly polarized wave is generated by the single point (P) feeding in the transmitting antenna, the band of the circularly polarized wave is relatively narrow. Circularly polarized waves are generated in the transmitting antenna by feeding at two points (Q1, Q2), and the band of circularly polarized waves becomes wider than that of the transmitting antenna by using a 90-degree hybrid coupler or a Wilkinson type power divider. . This is shown in FIG. FIG. 3 shows an example of the coupling amount between transmission and reception in that case. As can be seen, the two antennas are largely coupled in the reception frequency band, but the coupling amount is small in the transmission frequency band.

Before explaining the reason for this, the coupling between the transmitting and receiving antennas when both the transmitting antenna and the receiving antenna are completely circular polarized waves (that is, the axial ratio is 0 dB) in all bands will be described. It is assumed that radio waves are radiated from the transmitting antenna in the radiation direction (upward direction in FIG. 1), for example, as right-handed circularly polarized waves. At this time, radio waves leak to the back of the transmitting antenna (downward in FIG. 1) as left-handed circularly polarized waves, which are polarized waves in opposite directions. Here, if there is a receiving antenna behind the transmitting antenna and the receiving antenna operates only with the right-handed circularly polarized wave, the radio wave of the left-handed polarized wave leaking from the transmitting antenna will not be transmitted to the receiver side. The reason for this is that left-handed polarized waves entering the receiving antenna are
When power is supplied using a hybrid coupler, power is consumed by inputting to the terminating resistor in the isolation port, and when using a Wilkinson type power divider, power is input to the resistor inside the divider. Is consumed.

Therefore, as long as the transmitter and the receiver operate with the complete circular polarization in the same direction and the power supply circuit has a mechanism for absorbing the reverse polarization component somewhere, there is no coupling between the transmitter and the receiver.
In this case, even if it is not a perfect circular polarization, the coupling between the transmitting and receiving is reduced if it has a certain degree of circular polarization characteristics over a wide band including the transmission and reception frequency bands. In the configuration of the conventional example shown in FIG. 11, the transmission / reception antennas have a good axial ratio over a relatively wide band because circular polarization is generated using a hybrid coupler or a Wilkinson type power divider by two-point feeding. It is possible to reduce the coupling between transmission and reception. On the other hand, in the embodiment of the present invention shown in FIG. 1, both the transmitting and receiving antennas are circularly polarized waves to some extent in the transmission frequency band, and the receiving antenna side absorbs the reverse polarization component. Since there is a mechanism to do so, the coupling between transmission and reception becomes small. On the other hand, in the reception frequency band, the reception antenna operates as a circularly polarized wave, but the transmission antenna operates only with a linearly polarized antenna at this frequency, so the right-handed and left-handed circularly polarized wave components are the same. It is considered as there is a large bond. However, in reality, it suffices to prevent the radio wave from leaking from the transmitting antenna, and it suffices that a high transmission-reception separation is realized only in the transmission frequency band. That is, also in the present invention, the leakage of the transmission radio wave can be suppressed without any practical problems. In the present invention, since the transmission antenna is used for single-point (P) feeding and there is no need to provide a hybrid coupler or a Wilkinson type power divider, the configuration is much simpler than the conventional example, and there are many advantages.

Further, the hybrid coupler or the Wilkinson type power divider used for the receiving antenna can be constructed by using a plane circuit. FIG. 4 shows another embodiment of a circular polarization antenna for both transmission and reception, which is a hybrid coupler using a microstrip line. As shown in the cross-sectional view of FIG. 4A, the dual-use circularly polarized antenna for transmission / reception includes a ground conductor 18 and a dielectric substrate 12 having a receiving patch 14.
And the dielectric substrate 17 on which the transmission patch 13 is formed is stacked. 4B is a top view of the dielectric substrate 17 viewed from above, and FIG. 4C is a top view of the dielectric substrate 12 viewed from above. As shown in FIG. 4C, the receiving patch 1
4 and the hybrid coupler 15 are formed on the same plane on the dielectric substrate 12, and the reception output is taken out by the coaxial line connected at the point R. The chip resistor 16 is connected to the other output end of the hybrid coupler 15 and
At the ground conductor 18.

With the configuration as shown in FIG. 4, the antenna for both transmission and reception is formed in a small size and thin shape including the power feeding circuit, which is very compact and lightweight. In this example, the receiving patch 14
And the planar circuit type hybrid coupler 15 are formed on the same surface, the upper and lower layers are electrically connected using a means such as a coaxial line or a through hole, and the planar circuit type hybrid coupler 15 is received. It is also possible to form it on a surface other than that, for example, on the back side of the ground conductor 18. In this case, it is possible to prevent unnecessary radiation from the microstrip line from affecting the radiation directivity of the antenna. In addition,
An example using a microstrip line has been shown in this description, but instead of this line, a triplate line,
Similar effects can be obtained by forming another planar circuit using a sun-pended line or the like.

In the above description, an example in which a 90-degree hybrid coupler or a Wilkinson type power divider is used in the power feeding circuit of the receiving antenna is shown, but the received power is combined with a phase difference of 90 degrees even if it is not this power feeding circuit. You can
What is necessary is that the reverse polarization component can be consumed by the resistance.
For example, the same effect can be obtained by using a rat race circuit or the like.

Although a rectangular patch antenna has been described as an example of the radiating element in the above description, a circular or other patch antenna may be used. Further, as a transmitting antenna, a similar effect can be obtained by using a circularly polarized plane antenna with one-point feeding such as a cross dipole, a cross slot, or a spiral in addition to the patch antenna. Further, as a power feeding method to the patch antenna, the same method can be applied by using an electromagnetic field coupling power feeding method represented by a slot coupling power feeding method or a power feeding method by another line other than the methods shown in the above embodiments. Can be obtained.

Next, an embodiment in which the antenna of the present invention is arrayed will be described. FIG. 5 shows a top view when an array antenna is constructed. Here, for simplicity, only the transmitting patch 5 and the receiving patch 3 and their respective feeding points are shown in the drawing, and the configuration of the element antenna is assumed to be the same as that of the embodiment shown in FIG. In this embodiment, the element antennas adjacent to each other have a positional relationship in which they are rotated by a certain angle in the horizontal plane and moved in parallel, and a so-called sequential arrangement is adopted. By rotating the plane of polarization with each element antenna and exciting each element with the phase corresponding to the plane of polarization using such a configuration, the circular polarization characteristics combined as an array antenna can be improved. . In particular,
As for the transmitting antenna, the element antenna alone has a good axial ratio only in a relatively narrow band, but by arraying the element antenna, the axial ratio can be improved in a wide band. This is convenient when a wide band is required as the band of the transmission frequency.

Further, in the embodiment of FIG. 5, by setting an arbitrary excitation amplitude and excitation phase for each element, the beam is deviated in a specific direction, the side rope is lowered, and the beam shape is changed. Can be changed. In this case, by using the antenna element of the present invention, it is possible to realize an array antenna having a high degree of separation between transmission and reception without causing a decrease in gain and deterioration of circular polarization characteristics.

In the above example, if a feeding circuit having good characteristics is used for the receiving antenna, the circular polarization characteristic of the receiving antenna is not so much improved even if the receiving antenna is arranged in a sequential arrangement. In this case, in order to simplify the feeding circuit of the array antenna with respect to the receiving system, a configuration in which the receiving antennas are not sequentially arranged but only the transmitting antennas are arranged may be considered.

Further, in the array antenna configured as shown in FIG. 5, the antenna element can be theoretically eliminated by setting the antenna elements as follows.
In the example of FIG. 1, as a matter of course, a case where the feeding circuit is designed so that the circular polarization characteristic of the receiving antenna is optimum in the receiving frequency band is shown. On the other hand, the element antenna of the array antenna having the configuration as shown in FIG. 5 has the same configuration as that of FIG. 1, but the feeding circuit is arranged so that the circular polarization characteristic of the receiving antenna becomes optimum in the transmission frequency band. To design. The circular polarization characteristic of the element antenna in this case is as shown in FIG. The element antenna has a circular polarization characteristic which is synthesized as an array antenna by performing a sequential arrangement in which the axial ratio deteriorates in the reception frequency band. Since the element antenna has a certain axial ratio in the reception band, the gain does not decrease even if beam scanning is performed. In addition, the greatest advantage of this case is that the transmission and reception are almost completely circularly polarized waves in the transmission frequency band, so that the coupling amount between the transmission and reception is only a very weak amount as described above. That is, by forming an array antenna as shown in FIG. 5 and designing both the transmitting antenna and the receiving antenna in the element antenna so as to have optimum circular polarization characteristics at the transmitting frequency, the isolation between transmitting and receiving is extremely high. It is possible to realize a high transmission / reception shared antenna. In the embodiment of FIG. 5, the same effect can be obtained even if the number of elements of the array antenna and the arrangement method are set differently.

Next, another embodiment of the transmitting / receiving shared planar antenna of the present invention will be described. FIG. 7 is a diagram showing another embodiment of the plane antenna for both transmission and reception of the present invention. Here, FIG.
(A) shows a cross-sectional view of the antenna, and the antenna is constructed by stacking six dielectric substrates 51 to 56 having conductor patterns formed by etching on both sides or one side. 7 (b) is a top view of the dielectric substrate 51 seen from above, FIG. 7 (c) is a top view of the dielectric substrates 52 and 53 seen from above, and FIG. 7 (d) is a dielectric substrate. 54 is a top view of the dielectric substrates 55 and 56, and FIG. 7E is a top view of the dielectric substrates 55 and 56. As shown in FIG. 7B, a circular patch 57 is formed of a conductive film on the dielectric substrate 51. Further, as shown in FIG. 7C, a circular conductor plate 58 is formed of a conductor film on the dielectric substrate 52, and slots 66 and 67 are formed therein. In addition, the dielectric substrate 5
A line 59 made of a conductor film is formed on the wiring 3, and the line 59 is set so as to intersect the slot 66 but not the slot 67. As shown in FIG. 7D, a circular patch 60 made of a conductive film is formed on the dielectric substrate 54. Further, as shown in FIG. 7E, a conductor plate 61 is formed on the dielectric substrate 55, and slots 68 and 69 are formed therein. A line 62 made of a conductive film is provided on the dielectric substrate 56, and the line 62 intersects with the slots 68 and 69. A Wilkinson type power distributor 70 is connected to the line 62. Here, 71 is a resistor, which is a film resistor or a chip resistor. A ground conductor 63 is formed under the dielectric substrate 56.

The operation of the antenna of the embodiment shown in FIG. 7 constructed as described above will be described below. This antenna is
The upper and lower three layers are transmission / reception antennas and the lower three layers are reception / transmission planar antennas.

In the transmitting antenna, the coaxial line 64 is connected to the line 59 at the point X and transmits a radio wave as a triplate line. This line directly feeds the slot 66 and indirectly couples with the non-excited slot 67 to generate circularly polarized waves in the transmitting patch 57. Therefore, the transmitting antenna operates as a circularly polarized wave antenna, and its operating frequency and axial ratio can be easily adjusted only by changing the size of the patch 57 and the lengths of the two slots 66 and 67. Further, as an advantage of using the antenna of such a system, impedance matching can be easily achieved by providing a 1/4 wavelength transformer and an open stub in the triplate line. Further, since the slot-coupled feed type microstrip antenna is used, the size of the antenna is smaller than that of a general direct feed system, which is advantageous in forming an array.

In the receiving antenna, the circularly polarized radio wave received by the circular patch 60 is received by the slots 68, 6 below it.
9 is electromagnetically coupled, and this electromagnetic field is transmitted to the line 62. Here, the length of the line is adjusted so that a phase difference of 90 degrees is relatively generated between the two slots so that circularly polarized waves of desired polarization components can be combined. A Wilkinson type power distributor 70 is provided to combine radio waves from the two lines. Here, a resistor 71 is provided to absorb an unbalanced component (reverse polarization component) during synthesis. As the resistor 71, a small and thin resistor such as a film resistor or a chip resistor is used. A 90-degree hybrid may be used here instead of the Wilkinson type power distributor.
The line 64 for feeding the transmitting antenna is a patch 60.
Pass vertically through the center of. By doing so, the influence on the receiving antenna can be eliminated, and the generation of unnecessary higher-order modes in the receiving antenna can be suppressed.

With the above structure, the receiving antenna operates as a circularly polarized wave antenna and is output by being connected to the line 65 at the point Y. The operating frequency and axial ratio of the receiving antenna can be easily adjusted by changing the size of the patch 60 and the lengths of the two slots 68 and 69.
In addition, as an advantage of using an antenna of this type,
Impedance matching can be easily achieved by providing a 1/4 wavelength transformer and an open stub in the triplate line. In addition, since the feeding circuit can be formed separately from the radiating element, it is possible to prevent the feeding circuit from affecting the radiation of the antenna, and the feeding circuit can be freely configured under the conductor plate 61. , Very convenient in production. Further, since the slot-coupled feed type microstrip antenna is used, the size of the antenna is smaller than that of the conventional direct feed system, which is advantageous in forming an array.

The embodiment of FIG. 7 shows an example in which the slot-coupling feed type microstrip antenna is used for both the transmitting antenna and the receiving antenna. In this case, only one of them is provided with the slot-coupling feed type microstrip antenna. Even if it uses it, the effect of each is not lost. In particular, by using a slot-coupled feed type microstrip antenna, design and adjustment can be performed independently by the transmitting and receiving antennas, which is very effective. Also, since the feeding circuit can be configured independently of the radiating element by using a triplate line or a microstrip line, it is possible to incorporate an amplifier with an MMIC device into the feeding circuit, and integrate an activated shared antenna for transmission and reception. It can be made small and thin, and is very effective.

FIG. 8 is a view showing still another embodiment of the plane antenna for both transmission and reception of the present invention. Here, FIG. 8A shows a cross-sectional view of the antenna. The dual antenna for transmitting and receiving of the present embodiment is constituted by stacking four dielectric substrates 81 to 84 each having a conductor pattern formed by etching on both sides or one side. Further, FIG. 8B shows the dielectric substrate 8
1 from above, FIG. 8C is a top view from above the dielectric substrate 82, and FIG. 8D is a dielectric substrate 83, 8
The top views of 4 are seen from above, respectively. As shown in FIG. 8B, a circular patch 85 made of a conductor film is formed on the dielectric substrate 81, and as shown in FIG. 8C, a conductor film is made on the dielectric substrate 82. A circular patch 86 is formed. Further, as shown in FIG. 8D, the dielectric substrate 83
A conductor plate 87 is formed on the upper part of the above, and slots 93 and 94 are formed therein. A line 88 made of a conductor film is provided on the dielectric substrate 84.
Intersect slots 93, 94. A hybrid coupler 95 is connected to the line 88. Dielectric substrate 84
A ground conductor 89 is formed below.

The operation of the antenna of the embodiment shown in FIG. 8 will be described below. This antenna is a common antenna for transmitting and receiving, in which only the upper one layer is a transmitting antenna and the lower three layers are receiving antennas.

In the transmitting antenna, the patch 85 is a microstrip antenna in which the receiving patch 86 is regarded as a ground conductor. The patch 85 is fed by the coaxial line 92 at the point T, and is short-circuited by the receiving patch 86 at the point S, so that the antenna resonates at a size half that of a general circular patch. In addition, the degenerate mode is separated in the patch 85 by the degenerate separation elements 90 and 91 formed of a conductor film, and circularly polarized waves are generated. The operation frequency and axial ratio are adjusted by adjusting the size of the patch 85 and the degenerate separation element 9.
This is performed by changing the size of 0,91. With such a configuration, the transmitting antenna becomes very small,
Since it can be done with just one layer, it is easy to manufacture.

The operation of the receiving antenna is the same as that of the embodiment shown in FIG. However, 9 in two slots
In this embodiment, a hybrid coupler 95 is used to provide a phase difference of 0 degree. Here, the reception output is connected to the coaxial line 96 at the point V and is transmitted to the receiver side.
It is connected to the coaxial line 97 at a point W, and this line is connected to a non-reflection end. This non-reflection termination is for absorbing the reverse polarization component, and the same operation is performed even if a resistor is provided on the plane circuit instead of the non-reflection termination. The operation of the receiving antenna and the advantage of using this method are the same as in the case of FIG.

The common antenna for both transmission and reception having the above-mentioned structure can be realized as a common antenna for transmission and reception by superimposing a small number of dielectric substrates, which is very effective in manufacturing, cost, downsizing and thinning. Further, since the transmitting antenna can be made considerably smaller than the receiving antenna, it is possible to realize a shared antenna for transmission and reception with a high degree of separation between transmission and reception even when the transmission frequency and the reception frequency are close to each other.

[0039]

As described above, according to the present invention, an antenna having good circular polarization characteristics for transmission and reception can be realized, and the antenna can be manufactured small in size, thin in thickness, simple and inexpensive. You can Moreover, the design of the transmitting and receiving antennas can be performed almost independently, which is convenient for manufacturing. Furthermore, since the transmitting antenna is provided for single-point power feeding and it is not necessary to provide a feeding circuit for the transmitting antenna, the configuration is remarkably simple as compared with the conventional example.

Also, by forming an array, it is possible to improve the axial ratio in a wide band and to realize a shared antenna for transmission and reception, which has a very high degree of separation between transmission and reception.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a circular polarization antenna for both transmission and reception according to the present invention.

FIG. 2 is a diagram D showing circular polarization characteristics in the embodiment of the present invention shown in FIG.

FIG. 3 is a diagram showing a transmission / reception coupling characteristic in the embodiment of the present invention shown in FIG.

4A is a cross-sectional view showing another embodiment of a circular polarization antenna for both transmission and reception according to the present invention, and FIGS. 4B and 4C are top views of a dielectric substrate, respectively.

FIG. 5 is a top view showing an embodiment in which the dual-use circularly polarized antenna for transmission and reception of the present invention is arrayed.

FIG. 6 is a diagram showing circular polarization characteristics in the embodiment shown in FIG.

FIG. 7A is a cross-sectional view showing another embodiment of a circular polarization antenna for both transmission and reception according to the present invention, and FIGS. 7B to 7E are top views of respective dielectric substrates.

8A is a cross-sectional view showing another embodiment of a circular polarization antenna for both transmission and reception according to the present invention, and FIGS. 8B to 8D are top views of respective dielectric substrates.

FIG. 9 is a diagram showing a configuration of a conventional transmitting / receiving shared antenna.

FIG. 10 is a diagram showing a configuration of a conventional transmission / reception separated antenna.

11A and 11B are a top view and a cross-sectional view showing an example of a conventional transmitting / receiving shared antenna.

[Explanation of symbols]

 1 ... Ground conductor 2, 4 ... Dielectric film 3, 14 ... Receiving patch 5, 13 ... Transmitting patch 6, 8, 9 ... Central conductor 7, 10, 11 ... Coaxial line 12, 17 ... Dielectric substrate 15 ... Hybrid coupler 51-56, 81-84 ... Dielectric substrate 57, 60, 85, 86 ... Circular patch 70 ... Wilkinson type power distributor 95 ... Hybrid coupler

[Procedure amendment]

[Submission date] March 4, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

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FIG. 11

Claims (2)

[Claims] 1. A flat type receiving antenna which is fed with a phase difference of 90 degrees relative to two feeding points, and a circular polarized wave which is located above the flat type receiving antenna and is fed at one feeding point. The plane receiving antenna is radiated, and a power distributor connected to a part of the line made of a conductor is connected to the two feeding points of the plane receiving antenna, and the plane receiving antenna receives the power. A circular polarization antenna for both transmitting and receiving, wherein the output port of the radio wave and the input port of the radio wave to be transmitted by the plane type transmission antenna are separated, and transmission and reception can be performed simultaneously. 2. A position in which an array antenna is configured by using an antenna for both transmission and reception consisting of the planar type reception antenna and the planar type transmission antenna as an element, and the adjacent elements are rotated by a certain angle in a horizontal plane and moved in parallel. 2. The dual polarized antenna for transmitting and receiving according to claim 1, wherein the circularly polarized antennas are arranged in a relationship.