TWI868965B - High-gain antenna with tunable frequency bands - Google Patents

Abstract

The present invention relates to a high-gain antenna with tunable frequency bands, primarily comprising a reflective plate unit, a dipole antenna unit and a H-shaped slot resonant antenna unit. The H-shaped slot resonant antenna unit is disposed above the dipole antenna unit by a first support as spaced a first distance apart from the dipole antenna unit. The dipole antenna unit is disposed above the reflective plate unit by a second support as spaced a second distance apart from the reflective plate unit. Accordingly, through the excitable dipole antenna coupled with the H-shaped slot resonant antenna, the whole antenna gain in the present invention is equivalent to a sum of gains for two resonators (i.e. a dipole antenna and a H-shaped slot antenna), and the additional arrangement of the reflective plate can allow the antenna radiation to be controlled in a unilateral direction, for the purpose of effectively improving the antenna gain as a whole. Furthermore, when the antenna of the present invention is operated in a low-frequency band, the electric field path lies in the energy excited by the dipole antenna, passing through the reflective plate and radiating via the slot; conversely, as operated in a high-frequency band, the electric field path lies in the radiation directly made by the dipole antenna through the slot. Also, the resonant frequency for the reflective plate and the dipole antenna can be adjusted from a dual band to a wideband by proper adjustment of the distance between the reflective plate and the dipole antenna, so as to obtain a high gain antenna with tunable frequency bands.

Description

High gain antenna with adjustable frequency band

The present invention relates to an antenna, and more particularly to an antenna that can effectively improve the overall gain and adjustable frequency band, so that the antenna array can be suitable for large base stations in the 3300-3800 MHz frequency band of 5G FR1 n78.

In the ever-changing environment of wireless communications, the demand for high-gain antennas is gradually increasing. High-gain antennas can concentrate energy to radiate in a specific direction. In the core technology of current base stations, high-gain antennas are a core component. They are directly related to the quality of communication. Their use is also directly related to the design of the communication system architecture. In order to ensure good communication quality for mobile devices, it is extremely important to use high-gain antennas in base station array antenna units.

The stacked antenna used in existing high-gain antennas is a set of metal patches placed in front of the slot antenna to couple and excite it. The stacking method makes the overall structure larger. If it is designed in the form of a traditional dipole antenna, the overall bandwidth will be slightly reduced due to the larger impedance of the open end.

Today, the inventor proposes an antenna for communication base stations with double resonance, high gain characteristics and adjustable frequency band in order to improve the problem of the existing stacked antenna having a bulky overall structure and the defect of the larger open-circuit end impedance caused by the traditional dipole antenna design, which slightly reduces the overall bandwidth.

The main purpose of the present invention is to provide a high-gain antenna with adjustable frequency band, which first designs an excitable dipole antenna, and then uses the dipole antenna to couple an H-shaped slot resonant antenna so that the overall antenna gain has the sum of the gains of two sets of resonators (the dipole antenna and the H-shaped slot antenna), and adds a reflector at the rear to control the radiation in a single-side direction to effectively improve the overall antenna gain, and by appropriately adjusting the distance between the reflector and the dipole antenna, the resonant frequency can be adjusted from dual-band to broadband, forming a high-gain antenna with adjustable frequency band.

The main purpose of the above-mentioned high-gain antenna with adjustable frequency band of the present invention is achieved by the following technologies:

A high-gain antenna with adjustable frequency band includes a reflector unit, a dipole antenna unit and an H-shaped slot resonant antenna unit; the H-shaped slot resonant antenna unit is supported by at least one supporting member and is arranged above the dipole antenna unit at a first distance, and the dipole antenna unit is also supported by at least one supporting member and is arranged above the reflector unit at a second distance; wherein:

The dipole antenna unit comprises a glass fiber plate, a feed line printed on one surface of the glass fiber plate, a first single arm, and a second single arm printed on the second surface of the glass fiber plate; the feed line is arranged from one end edge of the glass fiber plate to the center of the glass fiber plate, and the first single arm and the second single arm are respectively extended to the left and right from the terminal end of the feed line, so that the closed ends of the first single arm and the second single arm correspond to the feed line, and the open ends of the first single arm and the second single arm are far away from the feed line, and at the same time, the width of the first single arm and the second single arm gradually decreases from the open end to the closed end, so that the first single arm and the second single arm are approximately trapezoidal;

The H-shaped slot resonant antenna unit includes a first slot of a long rectangle on a single-sided glass fiber board, and a second slot of a thin strip is connected to each of the two short sides opposite to the first slot. The first slot and the second slot are arranged in an H shape, so that the dipole antenna unit is relatively located on the central axis of the first slot to form a coupled impedance matching mechanism.

In the frequency-adjustable high-gain antenna as described above, the second distance between the reflector unit and the dipole antenna unit is 4-8 mm.

The high-gain antenna with adjustable frequency band as described above, wherein the second distance between the reflector unit and the dipole antenna unit is 6 mm.

The advantages of the present invention are:

The high-gain antenna with adjustable frequency band of the present invention has an excitable dipole antenna unit, and then utilizes the dipole antenna unit to couple the H-shaped slot resonant antenna unit, so that the overall antenna gain has the sum of the gains of two sets of resonators (the dipole antenna unit and the H-shaped slot resonant antenna unit). In addition, a reflector unit is added behind the dipole antenna unit to control the radiation in a single-side direction, which can effectively improve the overall antenna gain. In addition, by appropriately adjusting the distance between the reflector and the dipole antenna, the resonant frequency can be adjusted from dual-band to broadband, forming a high-gain antenna with adjustable frequency band.

Please see the first picture.

The high-gain antenna with adjustable frequency band of the present invention comprises a reflector unit 1, a dipole antenna unit 2 and an H-shaped slot resonant antenna unit 3; wherein:

The reflector unit 1, the dipole antenna unit 2, and the H-shaped slot resonant antenna unit 3 are arranged in sequence from bottom to top, and the dipole antenna unit 2 and the H-shaped slot resonant antenna unit 3 are supported by at least one supporting member 4, so that the dipole antenna unit 2 and the H-shaped slot resonant antenna unit 3 are arranged at a first distance H1, and the reflector unit 1 and the dipole antenna unit 2 are arranged at a second distance H2.

The dipole antenna unit 2 has a glass fiber plate 21, and the glass fiber plate 21 has a first surface 211 and a second surface 212 opposite to each other. A feed line 22 is printed on the first surface 211 from one end of the glass fiber plate 21 to the center of the glass fiber plate 21; a first single arm 23 is printed on the first surface 211 at the end of the corresponding feed line 22 and extends to the right, so that the first single arm 23 gradually decreases in width from the open end to the closed end, so that the first single arm 23 is approximately trapezoidal; a first single arm 23 is printed on the second surface 212 at the end of the corresponding feed line 22 and extends to the right, so that the first single arm 23 gradually decreases in width from the open end to the closed end, so that the first single arm 23 is approximately trapezoidal. A second single arm 24 is extended from the left printing, and the width of the second single arm 24 gradually decreases from its open end to the closed end, so that the second single arm 24 is approximately trapezoidal, and is arranged corresponding to the first single arm 23; that is, the first single arm 23 and the second single arm 24 extend to the left and right respectively from the terminal end of the feed line 22, and the closed ends of the first single arm 23 and the second single arm 24 correspond to the feed line 22, and the open ends of the first single arm 23 and the second single arm 24 are far away from the feed line 22, and at the same time, the width of the first single arm 23 and the second single arm 24 gradually decreases from their open ends to the closed ends to be approximately trapezoidal;

The H-shaped slot resonant antenna unit 3 has a glass fiber plate 31, on which a long rectangular first slot 32 is provided, and a thin strip-shaped second slot 33 is connected at two opposite short sides of the first slot 32, so that an H-shaped configuration is formed between the first slot 32 and the two second slots 33, and the dipole antenna unit 2 is relatively located on the central axis of the first slot 32, so that a coupling impedance matching mechanism is formed between the dipole antenna unit 2 and the H-shaped slot resonant antenna unit 3.

<Example>

The dipole antenna unit 2 is made on a glass fiber board 21 (FR4). Since the resonance path of the dipole antenna unit 2 is approximately half the operating wavelength (0.5 λ ₀ ), the desired operating frequency can be obtained by adjusting the length and width of the dipole antenna unit 2. If the wavelength in different media is to be obtained, it can be obtained by the following formula (1), where λ _s is the wavelength in the substrate medium, ε _eff is the effective dielectric constant and ε _r is the relative dielectric constant of the glass fiber board 21.

........................................Formula (1)

The first arm 23 and the second arm 24 of the dipole antenna unit 2 are designed in a gradual variation scheme, which can make the impedance more balanced and achieve bandwidth expansion. The dipole antenna unit 2 is printed on the glass fiber board 21, with a relative dielectric constant of 4.4 and a loss tangent of 0.02. The overall size of the dipole antenna unit 2 is 50 × 15 × 0.8 mm ³ .

The resonant frequency of the H-shaped slot resonant antenna unit 3 is determined by the aperture area of the first slot 32. When the electric field reaches its maximum value at the center of the aperture, the aperture length is approximately half of the resonant wavelength 0.49 λ ₀ . If the feeding position is changed, the direction and shape of the radiation pattern will also change. In this embodiment, the H-shaped slot resonant antenna unit 3 is made of a single-sided glass fiber board 31 (FR4) with a size of 50×50×0.4 mm ³ .

During assembly, the dipole antenna unit 2 is placed at the center of the H-shaped slot resonant antenna unit 3, and the distance between the dipole antenna unit 2 and the H-shaped slot resonant antenna unit 3 is H ₁ , which is a coupled resonance mode, and the distance between the dipole antenna unit 2 and the rear reflector unit 1 is H ₂ . In addition, the dipole antenna unit 2 must be located on the central axis of the first slot 32 of the H-shaped slot resonant antenna unit 3, which is a coupled impedance matching mechanism. Among them, the first figure (a) to (e) discloses the geometric structure diagram of the reflector unit 1, the dipole antenna unit 2, the H-shaped slot resonant antenna unit 3 and the gaps between them of the antenna of this embodiment. For the detailed parameters in the first figure (a) to (e), please refer to Table 1. After assembly, the overall antenna size is 80 × 80 × 13 mm ³ .

＜Table 1＞ Parameter Data (mm) Parameter Data (mm) H ₁ 5(0.058λ ₀ ) _H2 6(0.07λ ₀ ) L ₁ 50 L ₂ 40 L ₃ 30 L ₄ 17.5 L ₅ 80 W ₁ 8 W ₂ 3 W ₃ 5 W ₄ 15 W ₅ 1.5 W ₆ 3 W ₇ 6 W ₈ 3 - -

Because the H-shaped slot resonant antenna unit 3 is the resonator of the dipole antenna unit 2, special attention must be paid to the direction of the resonant electric field of the two. Since the direction of the current after the dipole antenna unit 2 is excited must be parallel to the direction of the electric field, the dipole antenna unit 2 must be placed perpendicular to the magnetic current direction of the H-shaped slot resonant antenna unit 3, or parallel to the electric field direction of the H-shaped slot resonant antenna unit 3, so that the dipole antenna unit 2 and the H-shaped slot resonant antenna unit 3 can achieve the maximum amplification effect. A reflector unit 1 is added behind the dipole antenna unit 2 to concentrate the residual radiation energy at the rear to the front, thereby improving its gain. If the dipole antenna unit 2 and the H-shaped slot resonant antenna unit 3 share a common ground, no double resonance characteristic will be generated, and it will be just a basic slot antenna. Therefore, in this embodiment, the dipole antenna unit 2 and the H-shaped slot resonant antenna unit 3 do not share a common ground.

＜Measurement Results＞

The following is the simulation of the high gain antenna of the present invention using the antenna simulation software High Frequency Structure Simulated (HFSS).

Please refer to the second figure, which shows the simulation and measured results of the high-gain antenna _S11 of the present invention. The measured and simulated results are quite consistent, and both can cover the fifth-generation mobile communication 5G FR1 n78 (3300～3800 MHz) operating frequency band.

＜Observation by stimulus＞

The excitation source of the high-gain antenna of this embodiment is the dipole antenna unit 2, so the excitation source is observed first. As shown in the third figure, the S11 simulation diagrams of (1) dipole antenna unit 2, (2) H-shaped slot resonant antenna unit 3, (3) dipole antenna unit 2 and H-shaped slot resonant antenna unit 3, (4) dipole antenna unit 2 and H-shaped slot resonant antenna unit 3 plus reflector unit 1 are respectively simulated _; from the third figure, it can be seen that the dipole antenna unit 2 resonates at about 2700~3400 MHz, the center frequency point is 3050 MHz, and the best matching point is at 3000 MHz. Among them, the length of the dipole antenna unit 2 ( _L4 *2+ _W5 ) 36.5 mm is equivalent to 0.371 The center frequency of the H-shaped slot resonant antenna unit 3 is 3790 MHz, and the length of the H-shaped slot resonant antenna unit 3 (L ₂ ) is 40 mm, which is equivalent to 0.395 .

The fourth figure shows the current distribution diagram of the dipole antenna unit 2 of the high gain antenna of the present invention at (a) f = 2750 MHz (b) f = 3630 MHz respectively; the fifth figure shows the magnetic current distribution diagram of the H-shaped slot resonant antenna unit 3 of the high gain antenna of the present invention at (a) f = 2750 MHz (b) f = 3630 MHz respectively; it can be seen from the fourth and fifth figures that the directions of the current and the magnetic current are perpendicular to each other.

As shown in the sixth figure, when the high-gain antenna of the present invention operates at a low frequency of 2750MHz, the electric field distribution cross-sectional diagram in (a) YZ Plane and (b) XZ Plane is disclosed. As can be seen from the sixth figure, when the high-gain antenna of the present invention operates at a low frequency of 2750MHz, the electric field path is firstly excited by the dipole antenna unit 2, then passes through the reflector unit 1 and then radiates the energy through the H-shaped slot resonant antenna unit 3; As shown in the seventh figure, when the high-gain antenna of the present invention operates at a high frequency of 3630MHz, the electric field distribution cross-sectional diagram in (a) YZ Plane and (b) XZ Plane is disclosed. As can be seen from the seventh figure, when the high-gain antenna of the present invention operates at a high frequency of 3630MHz, the electric field path is directly radiated from the dipole antenna unit 2 through the H-shaped slot resonant antenna unit 3.

Please refer to Figure 8, which is a comparison diagram of the gain of various types of antennas, including (1) dipole antenna unit 2, (2) H-shaped slot resonant antenna unit 3, (3) dipole antenna unit 2 and H-shaped slot resonant antenna unit 3, and (4) dipole antenna unit 2 and H-shaped slot resonant antenna unit 3 plus reflector unit 1. Among them, (1) the gain of dipole antenna unit 2 is about 2.5 dBi; (2) the gain of H-shaped slot resonant antenna unit 3 is about 5 dBi; and (3) the gain of dipole antenna unit 2 and H-shaped slot resonant antenna unit 3 is about 6-7 dBi; (4) the gain of dipole antenna unit 2 and H-shaped slot resonant antenna unit 3 plus reflector unit 1 is increased to more than 9 dBi. It can be seen that the gain of the high-gain antenna of the present invention is higher than any basic antenna type (dipole antenna, slot antenna), which proves that the high-gain antenna of the present invention can effectively radiate the radiation energy through the slot stacking.

Figures 9, 10, and 11 are 2D radiation patterns of the high-gain antenna of the present invention when operating in different frequency bands, simulated and measured. In the 2D pattern, the measured and simulated results are very similar. In the YZ Plane and XZ Plane, it can be seen that the addition of a reflector to the rear concentrates the remaining radiation energy in the rear to the front, so that the main radiation direction is the Z axis direction, in order to achieve the purpose of increasing the gain. Since the high-gain antenna of the present invention is excited by the dipole antenna unit 2, it can be found that there is a zero point in the Y axis direction of the XY Plane. Figures 12, 13, and 14 are 3D pattern diagrams of the high-gain antenna of the present invention when operating in different frequency bands, simulated and measured; from the above 2D and 3D radiation pattern diagrams, it can be clearly seen that the main radiation direction of the high-gain antenna of the present invention is the +Z direction.

Figure 15 shows the simulated and measured graphs of (a) gain and (b) efficiency of the high-gain antenna of the present invention. It can be seen from the simulated and measured graphs of (a) gain and (b) efficiency of Figure 15 that the measured and simulated results of the high-gain antenna of the present invention are consistent, with the measured gain being approximately 10 dB and the efficiency being approximately 80%.

Antenna-a shown in Figure 16 (a) is a structural diagram of a traditional dipole antenna, while Antenna-b shown in Figure 16 (b) is a progressive dipole antenna improved from Antenna-a. Figure 17 is a comparison diagram of S11 between Antenna-a in Figure 16 (a) and Antenna-b in Figure 16 (b). As can be seen from Figure ₁₇ , Antenna-a has a reduced bandwidth due to its own impedance not being smooth enough, while Antenna-b does not have this problem. Since the high-gain antenna of the present invention uses the dipole antenna unit 2 as the main emitting source, it is more appropriate to use an excitation source with a wider bandwidth. If the dipole antenna unit 2 uses a traditional form, the impedance is infinite due to the open ends at both ends, which causes the impedance itself to be not smooth enough and thus causes the bandwidth to be reduced. Therefore, the dipole antenna unit 2 of the present invention adopts a progressive dipole antenna as shown in FIG. 16 (b), thereby smoothing the impedance and effectively improving the bandwidth.

＜Slot shape changes＞

The same dipole antenna unit 2 is used to cover an H-shaped slot resonant antenna unit 3 with different slot structures.

As shown in Figure 18, Antenna-1 is a basic composite resonant slot configuration, Antenna-2 is an enlarged slot area, and Antenna-3 is an improved resonant type. Among them, Antenna-1 is a half-wavelength dipole antenna that excites a half-wavelength closed slot antenna. In the Antenna-2 part, because the effective radiation area of the Antenna-1 slot is insufficient, resulting in poor gain, it is enlarged. After the slot is enlarged, in order to achieve the required frequency band, the metal on the slot surface needs to be increased, thereby increasing the volume. In the Antenna-3 part, in order to have a sufficient effective radiation area, the large aperture of Antenna-2 is improved, and in order to reduce the metal surface area, an H-shaped slot is manufactured and the coupling amount is increased. From Figures 19 and 20, we can see that Antenna-1 does not produce a match, and from the figures, we can see that although Antenna-2 has a match, the gain effect is not high, and it cannot impedance match within the frequency band, which is not a good slot structure. Antenna-3, after being reduced, can still achieve an average gain of more than 6 dBi within the overall coverage frequency band, which is greater than the gain of any original antenna type (dipole antenna, slot antenna), and proves that the total energy in the overall structure includes the gain of the dipole antenna and the slot antenna.

＜First arm and second arm length＞

When other structures remain unchanged, the effect of the length of the dipole antenna unit 2 on the overall antenna is discussed, wherein the length of the first arm 23 (second arm 24) of the dipole antenna unit 2 is used as a parameter for discussion. As shown in Figure 21. Since the dipole antenna unit 2 is the emitting source, when frequency deviation occurs in practice, it needs to be adjusted to the required frequency band, and its variable is the first arm 23 (second arm 24) (i.e., _L4 in Figure 5). When _L4 is shortened to 16.5 mm, the resonance path of the dipole antenna is shortened. From the real and imaginary parts of Figures 22 and 23, it can be observed that the overall impedance increases, resulting in a frequency shift to a higher frequency. Then, when _L4 is increased to 18.5 mm, its resonant path increases, and the frequency shifts to a lower frequency as can be observed from the real and imaginary parts of Figures 22 and 23. However, adjusting the length of _L4 of dipole antenna unit 2 will inevitably cause the slope of the gradient to be different, and at the same time change the original capacitance and inductance characteristics of the antenna, causing impedance matching to be unavailable. Therefore, Figure 21 shows that the matching is poor in the designed frequency band.

＜Second slot length＞

From Figures 24, 25 and 26, we can see that when the length of the second slot 33 (i.e., _L3 in Figure 1) is changed to 26 mm, the real part and the imaginary part are reduced, resulting in failure to produce matching within the required frequency band. Then, when _L3 is changed to 34 mm, the impedance increases significantly and therefore failure to match.

＜First slot length + second slot width＞

Next, we see the parameter _L2 in the middle part of the H-shaped slot (see the first figure). Figures 27, 28, and 29 show the simulated _S11 , real impedance, and imaginary impedance of the parameter _L2 in the middle part of the H-shaped slot. It can be seen from Figures 28 and 29 that the real and imaginary parts do not change significantly, so the _L2 parameter is used to adjust the frequency. Then, it can be found in the figure that when _L2 is 38 mm or 42 mm, the resonant frequency will shift, so 40 mm is selected as the required length of this antenna structure.

＜Distance＞

Next, we discuss the distance relationship between the dipole antenna unit 2 and the H-shaped slot resonant antenna unit 3 (see Figure 30 (a)). It can be observed from Figure 30 (b) that as the distance _H1 between the dipole antenna unit 2 and the H-shaped slot resonant antenna unit 3 increases, the matching frequency of the resonant mode in the 3630 MHz band decreases significantly, and vice versa. This also proves that the Huygens principle is indeed transmitted to the slot and radiates energy in the form of a plane wave.

Then, the distance _H2 between the dipole antenna unit 2 and the reflector unit 1 is adjusted greatly to see whether this structure will be seriously affected by the distance (see Figure 31 (a)). Figure 31 (b) shows that the change of _H2 mainly affects the modal matching frequency of the 2750 MHz band. This can be combined with Figures 6 and 7 to prove that the 2750 MHz band is a mode that is excited by the dipole antenna unit 2 and then radiated secondary through the reflector unit 1.

According to the above discussion on the parameters of _H1 and _H2 , the dual-mode characteristics of this structure can be used to simply adjust its operating band and increase the operating band. The antenna structure after adjustment is shown in Figure 1, and the detailed structural parameters are shown in Table 2. It can be seen from Figure 32 that the operating band after adjustment can cover 5G n77 ~ n79 (3300 ~ 5000 MHz), and its gain part is about 7.5 ~ 11.5 dBi, and the efficiency part is about 87 ~ 95% as shown in Figures 33 and 34.

＜Table 2＞ Parameter Data (mm) Parameter Data (mm) H ₁ 3(0.04λ ₀ ) _H2 6.5(0.09λ ₀ ) L ₁ 40 L ₂ 36 L ₃ 34 L ₄ 12.6 L ₅ 70 W ₁ 11.5 W ₂ 1.5 W ₃ 2 W ₄ 15 W ₅ 1.5 W ₆ 3 W ₇ 5.6

From the above description, it can be seen that the high-gain antenna of the present invention is designed using the principle of double resonance of the antenna resonance antenna. It is constructed by a progressive dipole antenna and a single-layer H-shaped slot. The composite resonant antenna itself can have high gain characteristics, and a reflector is added at the back to more effectively increase the gain stack to 9 dBi. It also has dual-band modal characteristics to facilitate adjustment of the operating band and increase the operating bandwidth. This high-gain characteristic is a very good antenna unit for large base stations, and is suitable for new antenna units for large base stations with an operating frequency band of 3300~3800 MHz of 5G FR1 n78. In addition, the distance between the reflector and the dipole antenna can be properly adjusted so that the resonance frequency can be adjusted from dual-band to wideband, forming a high-gain antenna with adjustable frequency band.

The above examples are only partial embodiments of the present invention and are not intended to limit the present invention. Any slight changes and modifications based on the creative spirit and features of the present invention should also be included in the scope of this patent.

In summary, the embodiments of the present invention can achieve the expected effects, and the specific technical means disclosed therein have not been seen in similar products, nor have they been disclosed before the application. They are in full compliance with the provisions and requirements of the Patent Law. Therefore, we have filed an application for an invention patent in accordance with the law and sincerely request your review and grant of the patent. I would really appreciate the convenience.

1: Reflector unit 2: Dipole antenna unit

21: Fiberglass board 211: Surface

212:Surface 22:Feeding line

23: First single arm 24: Second single arm

3: H-shaped slot resonant antenna unit 31: Fiberglass board

32: First slot 33: Second slot

Figure 1: The geometric structure of the high-gain antenna with adjustable frequency band of the present invention; wherein, (a) a three-dimensional assembly diagram; (b) an assembly side view; (c) a top view of a reflector unit; (d) a top view of a dipole antenna unit; (e) a top view of an H-shaped slot resonant antenna unit.

FIG. 2 shows the simulation and measured diagram of the high-gain antenna _S11 of the present invention.

The third figure is the _S11 simulation diagram of the dipole antenna unit, the H-shaped slot resonant antenna unit, the dipole antenna unit and the H-shaped slot resonant antenna unit, and the dipole antenna unit and the H-shaped slot resonant antenna unit plus the reflector unit.

FIG. 4 is a diagram showing the current distribution of the dipole antenna unit of the high gain antenna of the present invention at (a) f = 2750 MHz and (b) f = 3630 MHz.

FIG5 is a diagram showing the magnetic flux distribution of the H-shaped slot resonant antenna unit of the high gain antenna of the present invention at (a) f = 2750 MHz and (b) f = 3630 MHz.

FIG. 6 is a cross-sectional view showing the electric field distribution in (a) the YZ Plane and (b) the XZ Plane of the high gain antenna of the present invention when operating at a low frequency of 2750 MHz.

FIG. 7 is a cross-sectional diagram showing the electric field distribution in (a) the YZ Plane and (b) the XZ Plane when the high-gain antenna of the present invention operates at a high frequency of 3630 MHz.

Figure 8: is a comparison diagram of various types of antenna gains, including a dipole antenna unit, an H-shaped slot resonant antenna unit, a dipole antenna unit and an H-shaped slot resonant antenna unit, and a dipole antenna unit and an H-shaped slot resonant antenna unit plus a reflector unit.

FIG. 9 shows the simulated and measured 2D radiation patterns of the high-gain antenna of the present invention operating in the 2750 MHz frequency band.

FIG. 10 shows the simulated and measured 2D radiation patterns of the high-gain antenna of the present invention operating in the 3500 MHz frequency band.

FIG. 11 shows the simulated and measured 2D radiation patterns of the high-gain antenna of the present invention operating in the 3630 MHz frequency band.

FIG. 12 shows the simulated and measured 3D field patterns of the high-gain antenna of the present invention operating in the 2750 MHz frequency band.

FIG. 13 shows the simulated and measured 3D field patterns of the high-gain antenna of the present invention operating in the 3500 MHz frequency band.

FIG. 14 is a 3D field diagram of the simulated and measured high-gain antenna of the present invention operating in the 3630 MHz frequency band.

FIG. 15 shows the simulation and actual measurement of the high-gain antenna of the present invention (a) gain diagram; (b) efficiency diagram.

Figure 16: (a) Antenna-a is a traditional dipole antenna. (b) Antenna-b is a progressive dipole antenna improved from Antenna-a.

FIG17 is a comparison diagram of _S11 between Antenna-a in FIG16 (a) and Antenna-b in FIG16 (b).

Figure 18: Schematic diagram of the antenna types of various slots; among them, Antenna-1 has double slots arranged on both sides, Antenna-2 has a single slot arranged in the middle, and Antenna-3 has an H-shaped single slot arranged in the middle.

Figure 19: _S11 comparison diagram of the slot antenna types in Figure 18.

Figure 20: Gain comparison of the various slot antenna types in Figure 18.

Figure 21: _S11 result diagram of the high gain composite resonant antenna _L4 simulation.

Figure 22: Real impedance results of the high gain composite resonant antenna _L4 simulation.

Figure 23: Simulation results of the imaginary impedance of the high-gain composite resonant antenna _L4 .

Figure 24: _S11 result diagram of the high gain composite resonant antenna _L3 simulation.

Figure 25: Real impedance results of the high-gain composite resonant antenna _L3 simulation.

Figure 26: Simulation results of the imaginary impedance of the high-gain composite resonant antenna _L3 .

Figure 27: _S11 result diagram of the high gain composite resonant antenna _L2 simulation.

Figure 28: Real impedance results of the high gain composite resonant antenna _L2 simulation.

Figure 29: The imaginary impedance result of the high gain composite resonant antenna _L2 simulation.

Figure 30: Simulation results of high-gain composite resonant antenna _H1 ; (a) side view of high-gain composite resonant antenna; (b) _S11 .

Figure 31: Simulation results of high-gain composite resonant antenna _H2 ; (a) side view of high-gain composite resonant antenna; (b) _S11 .

Figure 32: High gain antenna _S11 after frequency modulation.

Figure 33: Gain diagram of high gain antenna after frequency modulation.

Figure 34: Efficiency diagram of high gain antenna after frequency modulation.

1: Reflector unit

2: Dipole antenna unit

21: Fiberglass board

211: Surface

212: Surface

22: Feed line

23: First single arm

24: Second single arm

3: H-shaped slot resonant antenna unit

31: Fiberglass board

32: First slot

33: Second slot

Claims (3)

A high-gain antenna with adjustable frequency band includes a reflector unit, a dipole antenna unit and an H-shaped slot resonant antenna unit; the H-shaped slot resonant antenna unit is supported by at least one supporting member and is arranged above the dipole antenna unit at a first distance, and the dipole antenna unit is also supported by at least one supporting member and is arranged above the reflector unit at a second distance; wherein: The dipole antenna unit comprises a glass fiber board and a feed line printed on one surface of the glass fiber board, a first single arm, and a second single arm printed on the second surface of the glass fiber board; the feed line is arranged from one end edge of the glass fiber board to the center of the glass fiber board, and the first single arm and the second single arm are respectively extended to the left and right from the terminal end of the feed line, so that the closed ends of the first single arm and the second single arm correspond to the feed line, and the open ends of the first single arm and the second single arm are far away from the feed line, and at the same time, the width of the first single arm and the second single arm gradually decreases from their open ends to the closed ends, so that the first single arm and the second single arm are approximately trapezoidal; The H-shaped slot resonant antenna unit includes a first slot of a long rectangle on a single-sided glass fiber board, and a second slot of a thin strip is connected to each of the two short sides opposite to the first slot. The first slot and the second slot are arranged in an H shape, so that the dipole antenna unit is relatively located on the central axis of the first slot to form a coupling impedance matching mechanism. The high-gain antenna with adjustable frequency band as described in claim 1, wherein the second distance between the reflector unit and the dipole antenna unit is 4 to 8 mm. A high-gain antenna with adjustable frequency band as described in claim 2, wherein the second distance between the reflector unit and the dipole antenna unit is 6 mm.