CN203326117U - Compact-structure 16-element broadband substrate integration waveguide back chamber antenna array - Google Patents

Abstract

A compact 16-element broadband substrate integrated waveguide cavity-backed antenna array, including: a dielectric substrate covered with metal layers on both sides, and on the dielectric substrate, there are metallized through-holes distributed in a 2*2 array. Substrate-integrated waveguide back cavities, in each substrate-integrated waveguide back cavity, there are substrate-integrated waveguide sub-cavities distributed in a 2*2 array, which are composed of metallized through holes, respectively. The center of the 2*2 array of chip-integrated waveguide back cavities and the geometric center of each substrate-integrated waveguide back cavity are respectively provided with inductive coupling windows. By adjusting the offset between the slot and the center of the substrate integrated waveguide cavity, the radiation frequency of the slot is separated from the resonant frequency of the cavity, so that 16 slots can radiate in phase, and the radiation gain is superimposed, and the maximum gain direction is directly above.

Description

A compact 16-element broadband substrate integrated waveguide cavity-backed antenna array

technical field

The utility model patent relates to a compact broadband cavity-backed antenna array, in particular to a compact 16-element broadband substrate integrated waveguide cavity-backed antenna array. the

Background technique

Substrate integrated waveguide (SIW) is widely used in microwave and millimeter wave devices due to its low profile, low loss, and easy coplanarity with circuits. In recent years, many antennas based on substrate-integrated waveguide structures have emerged, such as substrate-integrated waveguide slot antenna arrays, substrate-integrated waveguide cavity-backed antennas and their arrays, and so on. The substrate-integrated waveguide cavity-backed antenna has the advantages of low profile, high radiation performance, and easy design. However, the low profile of the substrate integrated waveguide determines its high Q value, and the higher the Q value, the narrower the bandwidth of the antenna. Broadening the bandwidth of substrate-integrated waveguide cavity-backed antennas has become a research hotspot. The traditional substrate-integrated waveguide cavity-backed antenna array consists of two parts, namely, the feed network part and the radiation unit part. It is necessary to design a special feed network for feeding, which not only increases the area of the antenna array, but also complicates the design. How to reduce the area and complexity of the antenna array feed network has become a major problem in the design of large arrays.

Utility model content

The purpose of this utility model is to propose a compact 16-element broadband substrate-integrated waveguide-backed cavity antenna array, which not only has all the advantages of the substrate-integrated waveguide-backed cavity antenna, but also does not require a special feed network, and Compact structure and wide impedance bandwidth.

For realizing above object, the technical scheme that the utility model adopts is as follows:

A compact 16-element broadband substrate integrated waveguide cavity-backed antenna array, including: a dielectric substrate covered with metal layers on both sides, and on the dielectric substrate, there are metallized through-holes distributed in a 2*2 array. Substrate-integrated waveguide back cavities, in each substrate-integrated waveguide back cavity, there are substrate-integrated waveguide sub-cavities distributed in a 2*2 array, which are composed of metallized through holes, respectively. The center of the 2*2 array of chip-integrated waveguide back cavities and the geometric center of each substrate-integrated waveguide back cavity are respectively provided with inductive coupling windows.

The antenna array is composed of 16 closely connected substrate-integrated waveguide sub-cavities, and a coaxial probe is used to feed power at the center of the antenna array. The energy is coupled to each other in 16 cavities through 5 inductive coupling windows to achieve resonance. The upper surface of each substrate integrated waveguide back cavity is slotted as a radiation unit, and the radiation slot deviates from the center of the cavity to form in-phase radiation. The back cavity not only serves as a radiation unit, but also serves as a feeding network. This novel antenna array structure does not require an additional feeding network, and the structure is very compact. This technology is very suitable for the design of large array antennas. By adjusting the offset between the slot and the center of the substrate integrated waveguide cavity, the radiation frequency of the slot is separated from the resonant frequency of the cavity, so that 16 slots can radiate in phase, and the radiation gain is superimposed, and the maximum gain direction is directly above. The impedance bandwidth of the antenna array is improved by adjusting the width of the slot. The coaxial probe is used to directly feed the cavity, no feeding network is required, the structure is compact, and the design is simple.

Beneficial effect:

The beneficial effect of the utility model is that the antenna array not only has the advantages of low profile, low loss, and easy integration with circuits of general substrate integrated waveguide cavity-backed antennas, but also does not need a feeding network, and has a simple and compact structure. At the same time, its bandwidth is more than double that of ordinary cavity-backed antennas (only about 5%), and its impedance bandwidth reaches 12%. Thanks to the low-loss characteristics of the substrate-integrated waveguide, the 16-element antenna array has the advantage of high gain, with a maximum gain of 17.3dB. 

Description of drawings

Fig. 1 is a schematic diagram of the front structure of the utility model. In the figure, 1 is the substrate integrated waveguide back cavity, surrounded by metallized through holes, 2 is the radiation slot, 3 is the inductive coupling window, and 4 is the coaxial probe, which is fed in the center of the antenna array.

Fig. 2 is a schematic cross-sectional structure diagram of the utility model. Figure 4 is a coaxial probe.

Fig. 3 is a schematic diagram of the variation of the return loss of the antenna array of the present invention with the offset.

Fig. 4 is a schematic diagram of the variation of the return loss of the antenna array of the present invention with the width of the slot.

Fig. 5 is a schematic diagram of the simulated return loss of the antenna array of the present invention.

Fig. 6 is a schematic diagram of simulation gain of the antenna array of the present invention.

Fig. 7 is a simulation direction diagram of the E plane of the antenna array of the present invention.

Fig. 8 is the H plane simulation direction diagram of the antenna array of the present invention. the

Detailed ways

A compact 16-element broadband substrate integrated waveguide cavity-backed antenna array, including: a dielectric substrate covered with metal layers on both sides, and on the dielectric substrate, there are metallized through-holes distributed in a 2*2 array. Substrate-integrated waveguide back cavities, each substrate-integrated waveguide back-cavity is provided with substrate-integrated waveguide sub-cavities 1 composed of metallized through-holes distributed in a 2*2 array, and distributed in a 2*2 array Inductive coupling windows 3 are respectively provided at the center of the 2*2 array of substrate-integrated waveguide back cavities and the geometric center of each substrate-integrated waveguide back cavity. In this embodiment, a radiation slot 2 is provided in each substrate-integrated waveguide sub-cavity 1 and the radiation slot 2 deviates from the center of the substrate-integrated waveguide sub-cavity 1. The center of the 2*2 array of chambers is provided with a coaxial probe 4 .

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

The antenna array consists of 16 closely connected substrate-integrated waveguide back cavities 1 to form a 16-element antenna array. The substrate-integrated waveguide back cavity is surrounded by metallized through-holes, forming a waveguide structure with low profile and easy integration. Through five inductive coupling windows 3, the 16 cavities are communicated, so that energy can resonate in all cavities. The coaxial probe 4 is used to feed power at the center of the antenna array, as shown in Figure 1, so that the energy can reach each substrate integrated waveguide cavity symmetrically and uniformly, and form resonance. The back cavity not only acts as a radiation unit, but also serves as a feed network. This novel antenna array structure does not require an additional feed network, and the structure is very compact. This technology is very suitable for the design of large array antennas. The upper surface of each substrate integrated waveguide back cavity is slotted as a radiation unit. In order to achieve in-phase radiation, the radiation frequency of the slot is separated from the resonant frequency of the cavity by adjusting the offset of the slot from the center of the substrate integrated waveguide cavity, so that the current around each slot can be kept in the same phase, so as to achieve radiation gain superposition, and The direction of maximum gain is aimed directly above. The curve of the return loss changing with the offset is shown in Figure 3. With the increase of the offset, the radiation frequency of the slot is gradually separated from the resonant frequency of the cavity. When the offset is about 2mm, the bandwidth is wide and the matching is good. . By increasing the width of the slot and optimizing the aspect ratio of the slot, the impedance bandwidth of the antenna array is widened. The curve of the return loss changing with the slot width is shown in Figure 4. As the slot becomes wider, the bandwidth of the antenna expands. When the slot width reaches 2 mm, the impedance matching will deteriorate as the width increases. The final optimized return loss curve is shown in Figure 5. The return loss is less than -10dB in the frequency range from 19GHz to 21.4GHz, and the antenna impedance bandwidth reaches 12%, which is more than twice that of the general cavity-backed slot antenna. The gain curve of the antenna array is shown in Figure 6. Thanks to the low-loss characteristics of the substrate integrated waveguide, the 16-element antenna array has the advantage of high gain, with a maximum gain of 17.3dB. The normalized E-plane and H-plane pattern curves of the antenna array are shown in Figures 7 and 8. The E-plane half-beam width is 18 ⁰ , the maximum sidelobe is less than -14 dB, the H-plane half-beam is 20 ⁰ , the maximum sidelobe is less than -18 dB, and the maximum radiation direction is directly above.

Structurally, the size of the substrate-integrated waveguide sub-back cavity 1 determines the approximate working range of the entire antenna array, and the length of the radiation slot 2 determines the operating frequency of the antenna array. Adjusting the position of the slot can achieve in-phase radiation, and adjusting the width of the slot can Broaden the bandwidth of the antenna array. The size of the inductive coupling window 3 affects many performances of the entire antenna. The larger the coupling window, the lower the Q value of the cavity, so that the bandwidth of the antenna array will be widened, but if the coupling window is too large, it will affect the matching of the entire antenna array, worsen the return loss, and the energy cannot be radiated well. . the

In manufacturing, the antenna array is implemented on a 5mm×5mm high-frequency dielectric board with a thickness of 1.5mm and a dielectric constant of 2.2. The substrate-integrated waveguide structure is realized by drilling metallized through-holes on the dielectric board, and the substrate-integrated waveguide sub-cavity 1 is surrounded by the metallized through-holes. The feeding part uses coaxial probe 4 to feed power in the center of the antenna array. Because the operating frequency of the antenna array is about 20GHz, the frequency is relatively high. In order to ensure the high performance of the antenna array, high-frequency connectors are used for feeding. Copper is coated on the upper and lower surfaces of the dielectric board, and the radiation slot 2 is used as a radiation unit to corrode the copper-clad part. Because copper is placed in the air for a long time, it is easy to be oxidized. In order to ensure the long-term use of the antenna, tinning technology can be used to plate the outside of the copper skin.

According to the above, the utility model can be realized.

Claims (3)

1. A 16-element broadband substrate integrated waveguide cavity-backed antenna array with a compact structure, comprising: a dielectric substrate covered with a metal layer on both sides, characterized in that, the dielectric substrate is provided with a metallized through hole according to Substrate-integrated waveguide back cavities distributed in 2*2 arrays, and substrate-integrated waveguide sub-cavities (1) composed of metallized through-holes distributed in a 2*2 array are arranged in each substrate-integrated waveguide back cavity , inductive coupling windows (3) are respectively provided at the center of the 2*2 array of substrate-integrated waveguide back cavities distributed in a 2*2 array and the geometric center of each substrate-integrated waveguide back cavity. 2. The compact 16-element broadband substrate-integrated waveguide cavity-backed antenna array according to claim 1, characterized in that a radiation slot (2) is provided in each substrate-integrated waveguide sub-cavity (1) and radiates The slot (2) deviates from the center of the substrate-integrated waveguide sub-back cavity (1). 3. The compact 16-element broadband substrate-integrated waveguide-backed cavity antenna array according to claim 1 or 2, characterized in that, the 2*2 array center of the substrate-integrated waveguide-backed cavity distributed in the 2*2 array is set There are coaxial probes (4).

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