CN202384495U - Phased-array antenna with reconfigurable directional diagram - Google Patents

Abstract

The invention provides a phased-array antenna with a reconfigurable directional diagram, belongs to the technical field of communication, and relates to an antenna structure. The phased-array antenna at least comprises a linear phased-array, wherein the linear phased-array comprises a dielectric substrate, a metal ground plate and a radiation patch, wherein the radiation patch is formed by L exciting patches and (L+3) parasitic patches, wherein L is more than or equal to 2; one parasitic patch is arranged between two adjacent exciting patches; two parasitic patches are arranged outside two exciting patches on the left and right sides; a vertical seam and four transverse seams crossed with the vertical seam are formed in the middle of each parasitic patch; and three switches which are connected with the parasitic patches on two sides of the vertical seam are uniformly arranged in the vertical seam. According to the phased-array antenna, the phased-array is formed by the patch yagi antenna with the reconfigurable directional diagram, and the parasitic patches and different exciting patches are combined in different states by compressing the number of the parasitic patches of the reconfigurable unit, so that the dimension of the whole array is lowered, array minor level is reduced, and the beam scanning range is enlarged.

Description

A phased array antenna with reconfigurable pattern

technical field

The utility model belongs to the technical field of communication, and relates to an antenna structure, in particular to a phased array antenna with a reconfigurable pattern. the

Background technique

Several antennas are arranged in space and connected to each other to produce a directional pattern. This structure of multiple radiation elements is called an antenna array. If the phase of the excitation current of each unit antenna in the array is changed, the radiation pattern can be scanned in space, which is a phased antenna array. The concept of phased antenna array originated in 1889, and the first binary receiving array was successfully deployed in 1906. It developed vigorously in the 1920s and has been widely used so far. Changing the radiation pattern of the antenna can avoid noise sources or electronic interference, improve communication quality and security, and save energy by aligning signals to users who need to communicate. Therefore, in the fields of wireless communication, satellite communication and radar, etc., the pattern reconfigurable antenna has a great application space. Compared with the phased array composed of ordinary units, the phased array composed of reconfigurable antennas has the advantages of wider scanning range, larger gain, and more concentrated main lobe beam width. the

Antenna arrays come in a variety of geometries, the simplest of which is the linear array, in which the centers of the elements are placed along a straight line. In addition, there are planar arrays, the most popular of which is the rectangular array, the center of which is in a rectangular surface. Another class of antenna arrays is just beginning to develop. This is the conformal array, where the array elements conform to a non-planar surface. The array structure scheme proposed in this patent can be applied to linear arrays and ordinary planar arrays, and can also be applied to conformal arrays. the

The concept of reconfigurable antennas was first proposed in the 1983 patent "Frequency-Agile, Polarization Diverse Microstrip Antennas and Frequency Scanned Arrays". After the U.S. Defense Advanced Research Projects Agency (DARPA) developed a program called "Reconfigurable Aperture Program (RECAP)" in 1999, many research institutions conducted research on reconfigurable antennas and achieved a series of research results. At present, reconfigurable antennas have become a very popular research direction in the field of antennas, and have been applied in many aspects such as communication and radar. the

Reconfigurable antennas can be divided into three categories according to their reconfigurable antenna characteristics: frequency reconfigurable antennas, pattern reconfigurable antennas, and frequency and pattern reconfigurable antennas simultaneously. By changing the structure of the antenna, one or more of the antenna's operating frequency, radiation pattern, or polarization mode can be changed, so that one antenna can realize multiple antenna functions. the

Combining a phased antenna array with a reconfigurable antenna is a phased antenna array composed of reconfigurable antennas. Compared with ordinary phased arrays and single reconfigurable antennas, it has a beam scanning range Wider, greater gain and many other advantages. In recent years, the antenna array of this structure has been studied, such as the article "Sidelobe level reduction in wide-angle scanning array system using pattern-reconfigurable antennas" by Jen-Chieh Wu, Chia-Chan Chang et al. A linear equidistant array composed of reconfigurable array elements is compared with a single antenna element, and the sidelobe levels of phased arrays in different modes are analyzed. Yan-Ying Bai, Shaoqiu Xiao and others proposed a linear array with unequal spacing in "Wide-angle scanning phased array with pattern reconfigurable elements", which can also achieve a wide range of beam scanning and can effectively reduce side lobes level. the

Prior art literature "Xue-Song Yang, Bing-Zhong Wang, Weixia Wu, and Shaoqiu Xiao, "Yagi Patch Antenna With Dual-Band and Pattern Reconfigurable Characteristics," IEEE Antennas and Wireless Propagation letters, 2007, vol.6." A pattern reconfigurable antenna is proposed, as shown in Figure 1, the whole antenna is composed of five rectangular patches, the patch with a slightly larger size in the middle is the excitation element, and four rectangular patches with a slightly smaller size on both sides The slice acts as a parasitic element. There is a slot on each parasitic element, and three switches are installed in the slot. By controlling the state of the switch installed in the slot, the parasitic patch can be used as a director or a reflector. When the switch in the middle of the slot on the parasitic patch is off and the other two switches are closed, the parasitic patch acts as a guide; and when all three switches on the parasitic patch are turned off, the parasitic patch acts as a reflector device. When the two patches on one side of the excitation unit are directors, and the patch close to the excitation element on the other side is a reflector, the radiation pattern can be deflected toward the direction of the director. The effect of the parasitic patch state outside the reflector on the pattern is not obvious. Such an antenna that can change the beam direction of the radiation pattern is a reconfigurable microstrip patch Yagi antenna. the

Prior art literature Jen-Chieh Wu, Chia-Chan Chang, Ting-Yueh Chin, Shao-Yu Huang, and Sheng-Fuh Chang, "Sidelobe level reduction in wide-angle scanning array system using pattern-reconfigurable antennas," Microwave Symposium Digest (MTT), 2010IEEE MTT-S International, 2010, pp: 1274-1277. A reconfigurable phased array antenna with a pattern is proposed, and its structure is shown in Figure 2. The entire array consists of four identical array elements The array element is a reconfigurable monopole antenna fed by a microstrip. The array element of the antenna array is composed of a monopole as an excitation element and two microstrips connected to the floor through a switch. The microstrips are installed on both sides of the excitation monopole at the same distance as a parasitic element. When the switch is open, the parasitic microstrip acts as a director D, and when the switch is closed, the parasitic microstrip acts as a transmitter R. So this reconfigurable antenna has three modes, namely RD (beam pointing to the right), DD (beam pointing up) and DR (beam pointing to the left). When all array elements are in the same working mode, and then adjust the excitation current of the excitation patch, the beam pointing of the entire array can cover a certain range. In these three working modes, the beam pattern of the antenna array can cover a very large range in the upper half space. The gain of the phased array antenna is low; each array unit has its own different floor, the distance between the units cannot be too close, and the structure is not compact enough. the

Contents of the invention

The utility model provides a phased array antenna structure with a reconfigurable direction diagram. The phased array antenna structure adopts a reconfigurable Yagi microstrip antenna as an array element. The number of unit parasitic patches is reduced, so that when it forms a phased array, the unit size is smaller and the array performance is better. For the parasitic patch between two excitation patches, it forms an array unit together with different excitation patches in different modes, thereby improving the utilization rate of the parasitic patch, reducing the size of the array, and improving at the same time array performance. The utility model can be applied to aspects such as wireless communication, satellite communication, radar detection, etc., such as being applied to aircraft, ships, vehicle-mounted devices, and fixed or mobile terminal equipment of wireless communication. the

The technical scheme of the utility model is as follows:

A phased array antenna with reconfigurable pattern, as shown in FIG. 3 , at least includes the following linear phased array antenna. The linear phased array antenna includes a dielectric substrate, a metal ground plate and a radiation patch. The dielectric substrate is a rectangular dielectric substrate, and the metal ground plate covers the entire back of the dielectric substrate; the radiation patch is located on the front of the dielectric substrate, and consists of L excitation patches and L+3 parasitic patches, L≥2. The excitation patches are evenly distributed, one parasitic patch is arranged between every two adjacent excitation patches, and two parasitic patches are arranged outside the two excitation patches on the left and right sides. All the stimulus patches are rectangular in shape and have the same size; all the parasitic patches are rectangular in shape and have the same size; the size of the stimulus patch is larger than that of the parasitic patch. There is a vertical slit in the middle of each parasitic patch and four horizontal slits intersecting with the vertical slit, and three switches connecting the parasitic patches on both sides of the vertical slit are evenly arranged in the vertical slit, and each switch is located at the horizontal slit on the upper and lower sides Between, the whole parasitic patch figure is up and down, left and right symmetrical figure. the

The phased array antenna with reconfigurable directional pattern proposed by the utility model is an array antenna formed on the basis of the reconfigurable antenna with directional pattern shown in Fig. 1, but the array unit is different from the reconfigurable antenna in Fig. 1 different. The reconfigurable antenna in Figure 1 has an excitation patch, and there are two parasitic patches on both sides of the excitation patch. However, when the utility model constitutes a reconfigurable phased array antenna with a pattern, the excitation patch of an antenna unit in Fig. 1 is used as the basic antenna unit, but the parasitic patches on both sides of the excitation patch are adjusted. Between any two excitation patches, only one parasitic patch is reserved, and only two parasitic patches are reserved at the two edges of the entire array. In this way, the distance between the excitation units can be greatly reduced, so that the distance between the array units can be kept small, which is beneficial to reduce the side lobe level of the antenna array. Same as the pattern reconfigurable antenna shown in Fig. 1, each parasitic patch has three states through the switching of the switch, that is, as a director D, a reflector R or a common patch N. In this way, by changing the state of the parasitic patch and simultaneously changing the phase on different excitation units, a wide-range scanning of the beam pattern can be realized. Compared with the array composed of ordinary microstrip patch units, the utility model can realize wider scanning range, larger gain and lower side lobe. Compared with the reconfigurable array that does not reduce the number of parasitic patches between the excitation patches (that is, 4 parasitic patches are reserved between adjacent excitation patches), the utility model can greatly reduce the side lobe level, and can also Increased scan beam range. the

According to the same idea, that is, one parasitic patch is reserved between any two excitation patches, and two parasitic patches are reserved outside the excitation patch at the edge to form a reconfigurable linear Phased array, to achieve a larger range of beam scanning, and greater radiation gain. the

Another phased array antenna with a reconfigurable pattern provided by the utility model, as shown in Figure 4, the phased array antenna is composed of M horizontally arranged linear phased array antennas and N vertically arranged The rectangular phased array antenna formed by the above-mentioned linear phased array antenna has M≥2 and N≥2. Wherein, the horizontal linear phased array antenna and the vertical linear phased array antenna share an excitation patch, and the excitation signals are orthogonal to each other. the

In the linear phased array or the rectangular phased array provided by the utility model, if the excitation patch and the parasitic patch both adopt conformal patches, then the utility model can form a conformal reconfigurable array. the

By switching the state of the switch installed in the slot on the parasitic patch, the parasitic patch can be used as a director D, a reflector R or a common patch N during the operation of the array, and in different radiation modes of the array , the parasitic patch is combined with different excitation patches, thereby reducing the size of the array unit. the

The utility model is based on the miniaturization of the antenna array and the requirement of increasing the scanning range and reducing the side lobe level. The phased array is formed by using patch Yagi antenna units with reconfigurable pattern. By compressing the number of parasitic patches of the reconfigurable units, The size of the unit is reduced; and the parasitic patch is further combined with different excitation patches in different states to improve the reuse rate of the parasitic unit, so that the size of the entire array is greatly reduced, and the array sub- The lobe level expands the beam scanning range. Compared with antennas or arrays in all radiation directions, the utility model can provide higher gain, or can save energy under the condition of the same gain. This feature enables the utility model to be applied to wireless communication, satellite communication, radar detection, etc., such as being applied to aircraft, ships, vehicle-mounted devices, and fixed or mobile terminal equipment of wireless communication. the

Description of drawings

Figure 1 is a top and side view of a rectangular microstrip Yagi patch antenna.

Fig. 2 is a structure diagram of a phased array antenna in the prior art. the

Fig. 3 is a structural schematic diagram of the reconfigurable linear phased array antenna provided by the utility model. the

Fig. 4 is a schematic structural diagram of a rectangular phased array with reconfigurable pattern provided by the present invention. the

Fig. 5 is a top view of three different modes of the three-element linear array provided by the present invention, wherein (a) indicates the L mode, (b) indicates the R mode, and (c) indicates the N mode. the

Fig. 6 is the beam pattern (xoz surface) and the _S11 parameter curve of the three-unit linear array provided by the utility model under different modes, wherein (a) is the beam pattern under different modes, and (b) is different modes under the S ₁₁ parameter.

Detailed ways

A phased array antenna with reconfigurable pattern, as shown in FIG. 3 , at least includes the following linear phased array antenna. The linear phased array antenna includes a dielectric substrate, a metal ground plate and a radiation patch. The dielectric substrate is a rectangular dielectric substrate, and the metal ground plate covers the entire back of the dielectric substrate; the radiation patch is located on the front of the dielectric substrate, and consists of L excitation patches and L+3 parasitic patches, L≥2. The excitation patches are evenly distributed, one parasitic patch is arranged between every two adjacent excitation patches, and two parasitic patches are arranged outside the two excitation patches on the left and right sides. All the stimulus patches are rectangular in shape and have the same size; all the parasitic patches are rectangular in shape and have the same size; the size of the stimulus patch is larger than that of the parasitic patch. There is a vertical slit in the middle of each parasitic patch and four horizontal slits intersecting with the vertical slit, and three switches connecting the parasitic patches on both sides of the vertical slit are evenly arranged in the vertical slit, and each switch is located at the horizontal slit on the upper and lower sides Between, the whole parasitic patch figure is up and down, left and right symmetrical figure. the

The above-mentioned linear phased array antenna is an L (L≥2) element array, and the structure of the array element is formed on the basis of Fig. 1(a). Three different states of the parasitic patch can be realized by switching the switches installed in different positions in the slot of the parasitic patch, which are D (director), R (reflector) and N (normal), so that the antenna Arrays are available in a variety of operating modes. When the beam deflection caused by the different phase difference of the feed current of the excitation patch is not considered, and only the working conditions of the array unit in different states are considered, the antenna array has at least the following three basic modes, namely L-mode and N-mode and R-mode, as shown in Figure 5. In different modes, the number of tiles contained in the array unit is not the same. the

In L-mode, except for the two rightmost parasitic patches which take the R and N states respectively, all other parasitic patches take the D state. The excitation patch on the far right of the array together with one parasitic patch on the left and two parasitic patches on the right constitute an array unit, and the unit contains 4 patches; the excitation patch on the far left of the array and the Two parasitic patches form a unit, which contains 3 patches; the rest of the middle excitation patch and a parasitic patch on its left form an array unit, and the unit contains 2 patches. The beams of all elements are deflected to the left so that the entire array beams are deflected to the left. The array unit and its patch status are shown in Figure 5(a). the

In the R-mode, just opposite to the L-mode, except for the two leftmost parasitic patches which are in the N and R states respectively, all other parasitic patches are in the D state. The excitation patch on the leftmost side of the array and two parasitic patches on the left and one parasitic patch on the right form an array unit, and the unit contains 4 patches; the rightmost excitation patch and the two parasitic patches on the right The patches form an array unit, and the unit contains 3 patches; the remaining middle excitation patch and a parasitic patch on the right form an array unit, and the unit contains 2 patches. The beams of all elements are deflected to the right, so that the beam of the entire array is deflected to the right. The array unit and its patch status are shown in Figure 5(b). the

In N-mode, all parasitic patches take the N state, as shown in Fig. 5(c). In this mode, the parasitic patch has almost no effect, and the entire array is equivalent to an ordinary linear array with only excitation patches, and each array unit contains only one patch. The beam of each unit points above the patch, and the array beam mainly points directly above the patch. the

With such an array unit configuration method, the application efficiency of the parasitic patch is higher and more flexible, and the size of the entire array can be effectively reduced. At the same time, on the basis of these three modes, by changing the phase of the excitation current on the excitation patch, the beam scanning direction of the antenna array can be changed in a wider range, which greatly expands the beam scanning range of the array. the

For the reconfigurable microstrip patch Yagi antenna in Fig. 1 (prior art 1), a three-element linear reconfigurable array (Fig. 3) is formed by compressing the number of parasitic patches in the middle element. Switch the state of the parasitic patch to get three modes as shown in Figure 5. By adjusting the phase difference between different excitation units, the beam radiation pattern of the entire array can be changed. Table 1 shows the radiation parameters of the beam pattern obtained by setting several phase differences in the three modes. Figure 6 shows the intuitive beam radiation pattern (E plane) and the S in the three modes. ₁₁ parameter curves. Using a similar approach, more reconfigurable antenna elements can be used to form larger arrays, enabling scanning with wider angular range and greater gain.

Table 1

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Claims (3)

1. A phased array antenna with reconfigurable pattern, characterized in that it at least includes a linear phased array antenna: the linear phased array antenna includes a dielectric substrate, a metal ground plate and a radiation patch ; The dielectric substrate is a rectangular dielectric substrate, and the metal ground plate covers the entire back of the dielectric substrate; the radiation patch is located on the front of the dielectric substrate, and consists of L excitation patches and L+3 parasitic patches, L≥2; The patches are evenly distributed, and a parasitic patch is set between every two adjacent excitation patches, and two parasitic patches are arranged on the outside of the two excitation patches on the left and right sides; the shape of all excitation patches is rectangular , the same size; all parasitic patches are rectangular in shape and consistent in size; the size of the incentive patch is larger than that of the parasitic patch; there is a vertical slit and four horizontal slits intersecting the vertical slit in the middle of each parasitic patch, Three switches connecting the parasitic patches on both sides of the vertical seam are evenly arranged in the vertical seam, and each switch is located between the horizontal seams on the upper and lower sides. 2. the reconfigurable phased array antenna of pattern according to claim 1, is characterized in that, described phased array antenna is by the described linear phased array antenna of M horizontal arrangement and N vertical arrangement The rectangular phased array antenna composed of the linear phased array antenna, M≥2, N≥2; wherein, the horizontal linear phased array antenna and the vertical linear phased array antenna share the excitation patch, and the excitation signals interact with each other Orthogonal. 3. The phased array antenna with reconfigurable pattern according to claim 1 or 2, characterized in that the excitation patch and the parasitic patch are conformal patches.

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