CN104409841B - A Broadband Slot Antenna - Google Patents

Abstract

The invention discloses a broadband slot antenna, which comprises: the antenna comprises a plate-shaped dielectric substrate, a strip-shaped feed unit formed by metal foil on the upper surface of the substrate, a ground formed by metal foil on the lower surface of the substrate and an antenna radiation element formed by slotting in the ground, wherein the antenna radiation element comprises an inverse C-shaped slot and at least one first vertical sub-slot positioned inside the inverse C-shaped slot. The invention designs a broadband antenna with 10dB return loss range from 1.5GHz to 4.8GHz by using the step impedance sub-gap and the half-wavelength gap, can generate five resonance modes so as to expand the working bandwidth of the antenna, and is suitable for the fields of broadband communication and multi-mode communication.

Description

A Broadband Slot Antenna

technical field

The invention relates to the technical field of antennas for wireless mobile communications, in particular to a broadband slot antenna.

Background technique

In recent years, with the rapid development of wireless communication technology, people's demand for wireless communication services is increasing day by day. Many wireless terminals, such as mobile phones, tablet computers, etc., are designed to be compatible with many different communication standards, such as 2G, 3G, 4G , Wifi, etc. Therefore, the antenna responsible for radiating and receiving signals requires the ability to work in multi-band or broadband. The current research on multi-band is relatively mature, but there is still a lot of room for development in broadband.

Slot antennas, the more common ones are waveguide slot antennas and microstrip slot antennas. Microstrip slot antennas are often used in smart mobile terminals due to their coplanar structure, small size, light weight, and good properties of being easy to integrate with other components. However, the current slot antenna still faces the problem of narrow operating frequency band, so it is particularly important to design a slot antenna with a wide frequency band.

The broadband slot antenna shown in the data, the structural diagram of the broadband slot antenna is shown in Figure 1. For details, please refer to "Patent Application Number: 200880000579.4, Patent Name: Broadband Slot Antenna, Patentee: Hiroshi Kanno". Figure 1 shows the structure of a broadband slot antenna proposed in the patent. The broadband slot antenna proposed in the patent is mainly composed of a half-wavelength slot and a feeding structure. The patented antenna has a wide operating bandwidth and can cover The entire ultra-wideband frequency band (3.1GHz to 10.6GHz), but the frequency band below 3GHz is not within the working range of the antenna, so there are many uncertainties in designing a low-frequency antenna by using this patent.

The structure diagram of the slot antenna shown in the data is shown in Figure 2. For details, please refer to "Patent Application Number: 200810086973.6, Patent Name: Slot Antenna, Patentees: Kim Il-gyu, Kim Young-il, Chung Chang-won". What Fig. 2 shows is the structure of a kind of slot antenna that this patent proposes, and the slot antenna that this patent proposes is mainly made up of strip feed unit, ground and antenna element (by connecting two sub-slots formed on the ground of the base to form Formation) structure, its main advantage is that the area occupied by the antenna is small, but the working frequency band is narrow, which cannot meet the requirements of multi-communication standards.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art, and propose a broadband slot antenna. By improving the traditional microstrip slot antenna, the broadband slot antenna changes the uniform impedance slot into a step impedance slot, and realizes the control of the antenna resonance mode. On this basis, by introducing multiple independent slots, an additional A resonant mode of the antenna expands the working bandwidth of the antenna.

The object of the present invention is achieved through the following technical solutions:

A broadband slot antenna, the broadband slot antenna comprising:

a plate-shaped dielectric substrate 100, a strip-shaped feed unit 110 formed by a metal foil on the upper surface of the substrate 100, a ground 120 formed by a metal foil on the lower surface of the substrate 100, and an antenna radiation element 130 formed by slotting in the ground 120,

Wherein, the antenna radiating element 130 includes an inverted C-shaped slot and at least one first vertical sub-slot 136 inside the inverted C-shaped slot.

Preferably, the composition of the reverse C-shaped gap includes a first sub-slot 131, a second sub-slot 132, a third sub-slot 133, a fourth sub-slot 134, and a fifth sub-slot 135,

Wherein, the first sub-slit 131, its first end is formed at the edge of the ground, its second end is formed in the interior of the ground and meets the first end of the second sub-slit 132 at an angle of 90 degrees;

The fifth sub-slit 135, its first end is formed at the edge of the ground, and its second end is formed at the inside of the ground to meet the first end of the fourth sub-slit 134 at an angle of 90 degrees;

The third sub-slit 133, its first end is formed in the interior of the ground and is connected in line with the second end of the second sub-slit 132, and its second end is formed in the interior of the ground and is in line with the second end of the fourth sub-slit 134 connect.

Preferably, the first sub-slot 131 is the same as the fifth sub-slot 135 , and the second sub-slot 132 is the same as the fourth sub-slot 134 , so that the inverted C-shaped slit forms a vertically symmetrical structure.

Preferably, the first sub-slot 131 , the second sub-slot 132 , and the third sub-slot 133 are different from each other, forming step impedance sub-slots, and realizing the control of the resonance mode of the broadband slot antenna.

Preferably, the reverse C-shaped slot of the broadband slot antenna further includes a second vertical sub-slot 137, a third vertical sub-slot 138, and the first vertical sub-slot 136, the second vertical sub-slot 137 , The third vertical sub-slits 138 are arranged parallel to each other.

Preferably, the first vertical sub-slot 136 , the second vertical sub-slot 137 and the third vertical sub-slot 138 are slots working at half wavelength.

Preferably, the composition of the strip-shaped feed unit 110 includes a first strip-shaped feed sub-unit 111 and a second strip-shaped feed sub-unit 112,

Wherein, the second strip-shaped feeder unit 112 is perpendicular to the lower edge of the substrate 100, and the first end of the second strip-shaped feeder unit 112 is arranged at the lower edge of the substrate 100, the second strip The second end of the feed subunit 112 is connected to the first end of the first strip feed subunit 111;

The second strip-shaped feed sub-unit 112 forms an obtuse angle of J degrees with the first strip-shaped feed sub-unit 111 .

Preferably, the strip width of the first strip-shaped feed sub-unit 111 is gradually widened from the first end to the second end thereof.

Preferably, the second strip-shaped feed sub-unit 112 forms an obtuse angle of 135 degrees with the first strip-shaped feed sub-unit 111 .

Preferably, the port of the strip feed unit 110 has an impedance matching of 50 ohms.

Compared with the prior art, the present invention has the following advantages and effects:

1. Compared with the traditional uniform impedance slit, the present invention adopts the step impedance slit, which can realize the control of multiple resonance modes of the antenna.

2. A group of half-wavelength slots is added inside the anti-C-shaped slot, and an additional resonance mode is added to expand the working bandwidth of the antenna.

3. The antenna disclosed in the present invention has simple structural design, small volume and low cost, and can be applied to various communication systems.

Description of drawings

FIG. 1 is a schematic structural diagram of a broadband slot antenna in the prior art;

FIG. 2 is a schematic structural diagram of a slot antenna in the prior art;

Fig. 3 is a vertical sectional view of a broadband slot antenna proposed in the present invention;

Fig. 4 is a schematic structural diagram of a broadband slot antenna proposed in the present invention;

Fig. 5 is the simulation result schematic diagram of a kind of broadband slot antenna proposed in the present invention;

In the figure, reference signs are: 100-substrate, 110-strip feed unit, 111-first strip feed unit, 112-second strip feed unit, 120-ground, 130-antenna Radiating element, 131-first sub-slot, 132-second sub-slot, 133-third sub-slot, 134-fourth sub-slot, 135-fifth sub-slot, 136-first vertical sub-slot, 137-th Two vertical sub-slits, 138-the third vertical sub-slits.

detailed description

In order to make the object, technical solution and advantages of the present invention more clear and definite, the present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Example

The vertical cross-sectional view and structural schematic diagram of a wide-width slot antenna proposed in this embodiment are shown in Figure 3 and Figure 4 respectively. Manufacturing, circuit board etching and other techniques can be easily fabricated. The core content of the width slot antenna disclosed in this embodiment is to design a broadband antenna with superior performance by using the step impedance slot and the half wavelength slot.

A wide slot antenna disclosed in this embodiment is fabricated on a polytetrafluoroethylene double-sided copper-clad microstrip board with a dielectric constant of 4.2 and a thickness of 1.5mm in the form of a printed circuit board, and its structure is shown in Figures 3 and 4. It is shown that the slot antenna disclosed in this embodiment has a frequency bandwidth ranging from 1.5 GHz to 4.8 GHz in the range of 10 dB reflection loss, and the overall size is 66 mm×32 mm.

The broadband slot antenna proposed in this embodiment includes:

The plate-shaped dielectric substrate 100, the strip-shaped feed unit 110 formed by the metal foil on the upper surface of the substrate 100, the ground 120 formed by the metal foil on the lower surface of the substrate 100, and the antenna radiation element 130 formed by slotting in the ground 120, wherein the antenna The radiation element 130 includes an inverted C-shaped slot and at least one first vertical sub-slot 136 inside the inverted C-shaped slot.

In this embodiment, the reverse C-shaped slot of the broadband slot antenna further includes a second vertical sub-slot 137, a third vertical sub-slot 138, and a first vertical sub-slot 136, a second vertical sub-slot 137, The third vertical sub-slits 138 are arranged parallel to each other, and the specific placement is shown in FIG. 4 .

The composition of the reverse C-shaped slot includes a first sub-slit 131, a second sub-slit 132, a third sub-slit 133, a fourth sub-slit 134, and a fifth sub-slit 135, wherein the first sub-slit 131 has a first end formed At the edge of the ground, its second end is formed in the inside of the ground and meets the first end of the second sub-slit 132 at an angle of 90 degrees; the fifth sub-slit 135, its first end is formed at the edge of the ground, its The second end is formed in the inside of the ground and joins the first end of the fourth sub-slit 134 at an angle of 90 degrees; the third sub-slit 133, its first end is formed in the inside of the ground and the second end of the second sub-slit 132 connected in a straight line, the second end of which is formed inside the ground and connected in a straight line with the second end of the fourth sub-slot 134 .

The first sub-slot 131 is the same as the fifth sub-slot 135 , and the second sub-slot 132 is the same as the fourth sub-slot 134 , so that the inverted C-shaped slit forms a vertically symmetrical structure. The first sub-slot 131 , the second sub-slot 132 , and the third sub-slot 133 are different from each other and form step impedance sub-slots to realize the control of the resonance mode of the broadband slot antenna.

There are three points that need to be emphasized: first, one end of the first sub-slit 131 and the fifth sub-slit 135 is formed at the end edge of the ground, and the other end is formed at the inside of the ground with the second sub-slit 132 and the fourth sub-slit. One end of 134 is connected at an angle of 90 degrees; secondly, the first sub-slit 131 and the fifth sub-slit 135 have the same size, the second sub-slit 132 and the fourth sub-slit 134 have the same size, and the inverted C-shaped slit formed is symmetrical up and down ; Third, the first vertical sub-slit 136, the second vertical sub-slit 137, and the third vertical sub-slit 138 are placed vertically and parallel inside the anti-C-shaped slit, and the specific positions are optimized by simulation such as the distance from the slit 133 Decide. In order to achieve better impedance matching, the length and width of the first vertical sub-slot 136 , the second vertical sub-slot 137 , and the third vertical sub-slot 138 may be slightly different.

The composition of the strip feed unit 110 includes a first strip feed subunit 111 and a second strip feed subunit 112, which are used to receive current from the outside, and perform coupling so that the internal antenna disposed on the ground The component unit produces radiation.

Wherein, the second strip-shaped feeder unit 112 is perpendicular to the lower edge of the substrate 100, and the first end of the second strip-shaped feeder unit 112 is arranged at the lower edge of the substrate 100, and the second strip-shaped feeder unit The second end of 112 is connected to the first end of the first strip feed subunit 111 .

Wherein, the strip width of the first strip-shaped feed sub-unit 111 is gradually widened from the first end to the second end thereof, and this part is bent and gradually increased, which is for the first vertical sub-slit 136 , the second vertical sub-slot 137, and the third vertical sub-slot 138 provide better coupling and feeding, and achieve better matching in the entire frequency band.

In this embodiment, the second strip-shaped feed sub-unit 112 forms an obtuse angle of 135 degrees with the first strip-shaped feed sub-unit 111 , and the port of the strip-shaped feed unit 110 is matched with impedance of 50 ohms.

The working mode of the whole broadband slot antenna is that the electromagnetic signal is input from the port of the strip feed unit 110, coupled to the antenna radiating elements formed by each slot to radiate out, and the mode of receiving the signal is reversed.

Fig. 5 shows the simulation results of scattering parameters of the broadband slot antenna in this embodiment, the horizontal axis represents the signal frequency of the broadband slot antenna in this embodiment, and the vertical axis represents the magnitude of the return loss (S ₁₁ ). During the signal transmission process of the broadband slot antenna in this embodiment, part of the power of the signal is reflected back to the signal source, and the reflected power becomes reflected power. S ₁₁ represents the relationship between the input power of the signal passing through the broadband slot antenna in this embodiment and the reflected power of the signal, and the corresponding mathematical function is as follows: reflected power/incident power==20*log|S ₁₁ |.

The 10dB return loss of the broadband slot antenna ranges from 1.5GHz to 4.8GHz, and the relative bandwidth reaches 105%, covering GPS (1.575-GHz), LTE (1.710-2.690GHz), UMTS (1.920-2.170GHz), WLAN ( 2.4-GHz), WiMAX(2.5/3.5-GHz), UWB(3.1-4.8GHz, low frequency band). Such frequency bands are extremely suitable for broadband communication or multi-standard communication. It can also be seen from the figure that the principle of the slot antenna to generate broadband is that five resonance modes are generated in the band at about 1.5GHz, 2GHz, 3GHz, 3.8GHz, and 4.6GHz frequencies, of which the first four are generated by reverse C-shaped slots , the last one is generated by a group of half-wavelength slots inside the anti-C-shaped slot, and the five resonance modes are well matched, thus forming the broadband characteristics of the antenna, which is suitable for broadband communication or multi-standard communication.

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations, Simplifications should be equivalent replacement methods, and all are included in the protection scope of the present invention.

Claims (9)

1. A broadband slot antenna, characterized in that, the broadband slot antenna comprises: A plate-shaped dielectric substrate (100), a strip-shaped power supply unit (110) formed by the metal foil on the upper surface of the substrate (100), a ground (120) formed by the metal foil on the lower surface of the substrate (100), and an opening in the ground (120) Antenna radiating elements (130) formed by slots, Wherein, the antenna radiating element (130) includes an inverted C-shaped slot and at least one first vertical sub-slot (136) located inside the inverted C-shaped slot, The composition of the reverse C-shaped gap includes a first sub-slot (131), a second sub-slot (132), a third sub-slot (133), a fourth sub-slot (134), and a fifth sub-slot (135), Wherein, the first sub-slit (131), its first end is formed at the edge of the ground, and its second end is formed in the interior of the ground to meet the first end of the second sub-slit (132) at an angle of 90 degrees; The fifth sub-slit (135), its first end is formed at the edge of the ground, its second end is formed in the interior of the ground and meets the first end of the fourth sub-slit (134) at an angle of 90 degrees; The third sub-slit (133), its first end is formed in the interior of the ground and is connected in line with the second end of the second sub-slit (132), and its second end is formed in the interior of the ground and the fourth sub-slit (134) The second ends are connected in a straight line. 2. A kind of broadband slot antenna according to claim 1, characterized in that, the first sub-slot (131) is the same as the fifth sub-slot (135), the second sub-slot (132) is the same as the fourth sub-slot (134) are the same, so that the inverted C-shaped slit forms a symmetrical structure up and down. 3. A kind of broadband slot antenna according to claim 2, is characterized in that, described first sub-slot (131), the second sub-slot (132), the 3rd sub-slot (133) are different from each other, form step The impedance subslot is jumped to realize the control of the resonant mode of the broadband slot antenna. 4. A kind of broadband slot antenna according to claim 1, is characterized in that: the anti-C type slot interior of described broadband slot antenna also comprises second vertical sub-slot (137), the 3rd vertical sub-slot (138) ), and the first vertical sub-slit (136), the second vertical sub-slit (137), and the third vertical sub-slit (138) are arranged parallel to each other. 5. A broadband slot antenna according to claim 4, characterized in that: the first vertical sub-slot (136), the second vertical sub-slot (137) and the third vertical sub-slot (138) is a slit operating at one-half wavelength. 6. A kind of broadband slot antenna according to any one of claims 1 to 5, characterized in that: the strip feed unit (110) comprises a first strip feed subunit (111) and a first strip feed unit (111) Two strip feed sub-units (112), Wherein, the second strip-shaped feeder unit (112) is perpendicular to the lower edge of the substrate (100), and the first end of the second strip-shaped feeder unit (112) is arranged on the bottom edge of the substrate (100) At the lower edge, the second end of the second strip feed subunit (112) is connected to the first end of the first strip feed subunit (111); The second strip-shaped feeder unit (112) forms an obtuse angle with the first strip-shaped feeder unit (111). 7. The broadband slot antenna according to claim 6, characterized in that: the strip width of the first strip-shaped feed subunit (111) gradually increases from the first end to the second end thereof. 8. A broadband slot antenna according to claim 6, characterized in that: the second strip-shaped feeder unit (112) forms an obtuse angle of 135 degrees with the first strip-shaped feeder unit (111) . 9. The broadband slot antenna according to claim 6, characterized in that: the port of the strip-shaped feeding unit (110) has an impedance matching of 50 ohms.