A miniaturized ultra-wideband antenna with dual notch characteristics

Abstract

The present invention discloses a miniaturized ultra-wideband antenna with dual notch characteristics, including a dielectric substrate, a radiating patch, a microstrip feeder and an improved ground plane. The radiating patch is a rectangular structure, and symmetrically arranged corner cuts are formed on both sides of the bottom thereof, and a semicircular groove is dug on the top thereof; corner cuts are formed on both sides of the connection between the microstrip feeder and the bottom of the radiating patch; symmetrically arranged corner cuts are formed on both sides of the top of the improved ground plane, and irregular grooves are opened in the middle. The present invention adopts a monopole antenna structure as a radiating patch, realizes the miniaturization of the ultra-wideband antenna and has a simple structure, generates a stopband by introducing a T-shaped branch and etching a U-shaped narrow gap, effectively filters out the interference of different narrowband signals, realizes the mutual compatibility and cooperative communication of the ultra-wideband system and other narrowband communication systems, has the advantages of simple structure, miniaturization, strong anti-interference ability, and good radiation characteristics, has high practical value, and can be applied to a variety of ultra-wideband communication systems.

Description

Technical Field

[0001] The invention belongs to the technical field of wireless communication, and in particular relates to a miniaturized ultra-wideband antenna with dual notch characteristics. Background Art

[0002] In recent years, wireless communication technology has been developing and updating with the needs of people's work and life. The development trend of miniaturization, low cost and high efficiency of terminal equipment has gradually become prominent, which makes the antenna move towards the goal of miniaturization and broadband. Ultra-wideband technology has the advantages of high transmission rate, low power consumption and high resolution, and is widely used in radar remote sensing and military communications. The Federal Communications Commission (FCC) of the United States was established in 1934 as an independent agency of the US government. Since the FCC allocated the ultra-wideband frequency band of 3.1 to 10.6 GHz to the field of civil communications in 2002, ultra-wideband communication technology has become a key research object in academia and the field of wireless communications. As the core component of the system, the performance of the ultra-wideband antenna directly affects the transmission quality of the entire system.

[0003] Since the frequency band occupied by the ultra-wideband system is extremely wide, it contains many narrowband communication systems, such as the 3.3-3.6GHz wireless local area network (Worldwide Interoperability for Microwave Access, WiMAX) and the 8.01-8.5GHz International Telecommunication Union communication system. These narrowband communication bands will strongly interfere with the normal operation of the ultra-wideband system. In order to avoid the interference of these narrowband signals, it is necessary to design an ultra-wideband antenna with a notch characteristic. At the same time, in order to meet the requirements of today's increasingly miniaturized and portable electronic products, the miniaturization design of ultra-wideband antennas is currently a research hotspot at home and abroad.

[0004] In order to avoid electromagnetic interference between ultra-wideband systems and narrowband systems, the traditional method is to introduce a band-stop filter into the ultra-wideband system, but this undoubtedly increases the size of the system, the complexity of the design and the cost. At present, the simplest way to solve the problem of antenna filtering narrowband signals is to use an ultra-wideband antenna with a notch characteristic, which mainly adopts the slot method, the branch addition method and the parasitic unit method. For example, the reference "Shi Ronghua, Xu Xi, Dong Jian. Design and research of a dual-notch ultra-wideband antenna [J]. Journal of Electronics and Information Technology, 2014, 36 (02): 482-487" proposed an ultra-wideband antenna with a dual-notch characteristic. The antenna uses a circular monopole antenna structure as the radiation unit. The antenna generates two notch characteristics by opening a circular arc-shaped H-shaped slot in the center of the radiation patch and opening two L-shaped slots on the ground plane. The overall size of the antenna is 35.5*30*1.6mm 3 However, the antenna only filters out the interference of narrowband signals in the WiMAX and WLAN frequency bands and has a large physical size.

[0005] Another example is the Chinese patent with the patent name of "A novel circular notch ultra-wideband antenna with U-shaped groove" and the application number of 201410796959.0. It proposes a novel circular notch ultra-wideband antenna with U-shaped groove. The antenna consists of a circular radiation patch, a rectangular microstrip feeder and a rectangular ground plane. The double notch characteristics are generated by opening a U-shaped groove on the circular radiation patch and adding spiral ring resonators on both sides of the radiation unit. The physical size of the antenna is 38*38*0.812mm 3 , and the physical size is also large and not easy to integrate. Summary of the invention

[0006] In view of the above deficiencies in the prior art, the technical problem solved by the present invention is to provide an ultra-wideband antenna with a simple structure, small size, stable performance and dual-notch characteristics, which can filter out interference from different narrowband signals.

[0007] In order to solve the above technical problems, the present invention is implemented through the following technical solutions: the present invention provides a miniaturized ultra-wideband antenna with dual notch characteristics, including a dielectric substrate, a radiating patch, a microstrip feeder and an improved ground plate, the radiating patch and the microstrip feeder are both printed on the front side of the dielectric substrate, and the improved ground plate is printed on the back side of the dielectric substrate; the radiating patch is a rectangular structure, and symmetrically arranged first cut corners are formed on both sides of its bottom, and a semicircular groove is dug on its top; the microstrip feeder is connected to the bottom of the radiating patch, and second cut corners are arranged on both sides of the connection with the bottom of the radiating patch; symmetrically arranged third cut corners are formed on both sides of the top of the improved ground plate, and an irregular groove is opened in the middle.

[0008] As described above, the improved rectangular structure is used as the radiation patch to realize the miniaturization of the ultra-wideband antenna, filter out the interference of different narrowband signals, and realize the mutual compatibility and cooperative communication between the ultra-wideband system and other narrowband communication systems. The present invention has the advantages of miniaturization, simple structure, good radiation characteristics, and strong anti-interference ability.

[0009] Optionally, a T-shaped branch is arranged above the semicircular groove.

[0010] Furthermore, the T-shaped branch is located at the central axis of the dielectric substrate and is connected to the semicircular groove.

[0011] From the above, an improved rectangular structure is used as a radiation patch, and the characteristics of the monopole antenna, which occupies a small space and is easy to improve, are used to effectively expand the antenna bandwidth and reduce the antenna size; a semicircular groove is opened on the radiation patch to expand the low-frequency bandwidth of the antenna, save manufacturing materials and increase the number of notch structures; the introduction of T-shaped branches can produce stopband characteristics and the center frequency and bandwidth of the notch can be flexibly adjusted by adjusting the horizontal and vertical lengths of the T-shaped branches.

[0012] Furthermore, the irregular-shaped groove is located in the upper middle part of the improved ground plate and directly below the microstrip feeder, and the length of the irregular-shaped groove is 8.5-9.5 mm.

[0013] Optionally, the radius of the semicircular groove is 8.8-9.2 mm. The horizontal length of the first chamfered portion is 5.8-6.2 mm, and the vertical length is 8.5-9 mm.

[0014] Furthermore, the horizontal length of the T-shaped branch is 12.5-13.5 mm, and the vertical length is 7.8-8 mm.

[0015] Optionally, the microstrip feed line is a microstrip feed line with a characteristic impedance of 50Ω, a length of 13-14mm, and a width of 1.5mm; a U-shaped narrow gap is etched on the microstrip feed line, and the U-shaped narrow gap extends upward from the middle and lower part of the microstrip feed line, and the gap width of the U-shaped narrow gap is 0.19mm.

[0016] As described above, a second notch frequency band is generated by etching a U-shaped narrow gap on the microstrip feed line, and good notch characteristics are achieved by adjusting the width, length, and distance from the feed port of the U-shaped narrow gap, and the adjustment process is flexible. In addition, the notch characteristics are generated by introducing T-shaped branches and etching U-shaped narrow gaps, which has a simple structure, replaces the filter design, reduces the design cost and complexity, is easy to process, and is easy to produce.

[0017] Furthermore, the horizontal length of the third chamfered portion is 3-5 mm, and the vertical length of the third chamfered portion is 3-4 mm.

[0018] As shown above, an improved ground plate structure is adopted, and the triangular corners are cut off on both sides of the top of the ground plate, and irregular grooves are opened in the middle and upper part. This structure can produce a gradual resonance characteristic, so that the antenna can smoothly transition from one resonance mode to another, thereby further improving the antenna performance.

[0019] Optionally, the thickness of the dielectric substrate is 1 mm, and the length and width of the dielectric substrate are 31 mm and 18 mm respectively.

[0020] As shown above, a planar structure is adopted, which is small in size and compact in structure, and is easy to integrate with the RF front-end circuit.

[0021] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following is a detailed description in combination with the preferred embodiments and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the drawings of the embodiment are briefly introduced below.

[0023] Figure 1 is a structural diagram of a miniaturized ultra-wideband antenna with dual notch characteristics according to a preferred embodiment of the present invention;

[0024] Figure 2 This is a front structural diagram of the miniaturized ultra-wideband antenna with dual notch characteristics of the present invention;

[0025] Figure 3 It is a back structural diagram of the miniaturized ultra-wideband antenna with dual notch characteristics of the present invention;

[0026] Figure 4 It is a return loss curve diagram of the miniaturized ultra-wideband antenna with dual notch characteristics of the present invention;

[0027] Figure 5 The radiation pattern of the miniaturized dual-notch-band ultra-wideband antenna of the present invention at a frequency of 3 GHz;

[0028] Figure 6 The radiation pattern of the miniaturized dual-notch-band ultra-wideband antenna of the present invention at a frequency of 6.5 GHz;

[0029] Figure 7 This is the radiation pattern of the miniaturized ultra-wideband antenna with dual notch characteristics at a frequency of 10.5 GHz. DETAILED DESCRIPTION

[0030] The following is a detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings, which is a part of this specification and illustrates the principles of the present invention through examples. Other aspects, features and advantages of the present invention will become clear from the detailed description. In the referenced drawings, the same or similar components in different figures are represented by the same reference numerals.

[0031] like Figure 1-7 As shown in FIG. 1 , the miniaturized ultra-wideband antenna with dual notch characteristics of the present invention comprises a dielectric substrate 10, a radiation patch 20, a microstrip feed line 30 and an improved ground plane 40. The radiation patch 20 and the microstrip feed line 30 are printed on the front side of the dielectric substrate 10, and the improved ground plane 40 is printed on the back side of the dielectric substrate 10. Figure 1 As shown, the radiation patch 20 adopts a rectangular structure with cut corners on both sides of the bottom and a semicircular groove 21 on the top. The semicircular groove 21 is cut out on the radiation patch 20 and a symmetrical first cut corner portion 23 is formed on both sides of the bottom. The semicircular groove 21 is located at the top of the radiation patch 20, and the first cut corner portion 23 is located at the bottom of the radiation patch 20. The positions of the semicircular groove 21 and the cut corners on both sides are as shown in FIG. Figure 2 As shown, the radius of the semicircular groove 21 is 8.8-9.2 mm, and the radius of the semicircular groove 21 is preferably 9 mm. The horizontal length of the first chamfered portion 23 is 5.8-6.2 mm, and the vertical length thereof is 8.5-9 mm. Preferably, the horizontal length of the first chamfered portion 23 is 6 mm, and the vertical length thereof is 8.75 mm. In addition, a T-shaped branch 22 is introduced on the radiation patch 20, and the position of the T-shaped branch 22 is as shown in FIG. Figure 2 As shown, it is arranged above the semicircular groove 21, located on the central axis of the dielectric substrate 10 and connected to the semicircular groove 21. The horizontal length of the T-shaped branch 22 is 12.5-13.5 mm, and the vertical length is 7.8-8 mm. In a specific implementation, the horizontal length of the T-shaped branch 22 is set to 13 mm, and the vertical length is set to 7.9 mm.

[0032] The bottom of the radiation patch 20 is connected to a microstrip feed line 30 with a characteristic impedance of 50Ω. Second cut corners are set on both sides of the connection between the microstrip feed line 30 and the radiation patch 20. The length of the microstrip feed line 30 is 13-14mm and its width is 1.5mm. Preferably, the length of the microstrip feed line 30 is 13.5mm. A U-shaped narrow gap 31 is etched on the microstrip feed line 30 and extends upward from the middle and lower part of the microstrip feed line 30. The gap position is as shown in FIG. Figure 2 As shown, the slot width is 0.19 mm. A 50Ω microstrip line is used for feeding, and a U-shaped narrow slot 31 is etched on the microstrip feed line 30 to generate another notch frequency band. Good notch characteristics are achieved by adjusting the width, length, and distance from the feeding port of the U-shaped narrow slot, and the adjustment process is flexible.

[0033] The improved grounding plate 40 with third corner cutouts 41 on both sides of the top and irregular grooves 42 in the upper middle is printed on the lower side of the back of the dielectric substrate 10. The position of the third corner cutout 41 is as shown in FIG. Figure 3 As shown, two third corner cuts 41 are symmetrically arranged, and the third corner cuts 41 are triangular corners. It is understandable that the third corner cuts 41 can also be arc-shaped or other shapes. The arrangement of the third corner cuts 41 can improve the impedance matching characteristics of the antenna. The horizontal length of the third corner cuts 41 is 3-5mm, and the vertical length of the third corner cuts 41 is 3-4mm. Preferably, the horizontal length of the third corner cuts 41 is 4mm, and its vertical length is 3.534mm. The position of the irregular groove 42 of the improved ground plate 40 is as shown in FIG. Figure 3 As shown, the irregular groove 42 is located in the middle and upper part of the improved ground plate 40 and is located directly below the microstrip feed line 30. The length of the irregular groove 42 is 8.5-9.5 mm. Preferably, the length of the irregular groove 42 is 9 mm. The spacing between the two horizontal rectangles of the irregular groove 42 is 1 mm. The structure of the improved ground plate 40 can produce a gradual resonance characteristic, so that the antenna can smoothly transition from one resonance mode to another resonance mode, thereby further improving the performance of the antenna.

[0034] The ultra-wideband antenna in this embodiment is printed on a dielectric substrate 10 of FR4 epoxy resin material with a length, a width and a thickness of 31 mm, 18 mm and 1 mm respectively. The relative dielectric constant of the dielectric substrate 10 is 4.4.

[0035] In order to further illustrate the good performance of the ultra-wideband antenna with dual notch characteristics of the present invention, the electromagnetic simulation software HFSS15.0 was used to model and simulate the radio frequency characteristics of the present invention.

[0036] See also Figure 4 The bandwidth of the ultra-wideband antenna of the present invention with a return loss less than -10dB is 2.8-12.3GHz, which fully meets the ultra-wideband frequency band range specified by the FCC, and produces better notch characteristics in the 3.23-3.7GHz 8.01-8.66GHz frequency band, which can effectively filter out the electromagnetic interference caused by the two narrowband signals of WiMAX and the International Telecommunication Union.

[0037] See also Figure 5 , provides the radiation pattern of the ultra-wideband antenna at 3 GHz in an embodiment of the present invention, by Figure 5 It can be seen that the E-plane radiation pattern of the antenna presents directional radiation in the shape of an "8", and the H-plane radiation pattern of the antenna is approximately circular, presenting omnidirectional radiation characteristics.

[0038] See also Figure 6 , provides the radiation pattern of the ultra-wideband antenna at 6.5 GHz in an embodiment of the present invention, Figure 6 It can be seen that the E-plane radiation pattern of the antenna presents directional radiation in the shape of an "8", and the H-plane radiation pattern of the antenna is approximately circular, presenting omnidirectional radiation characteristics.

[0039] See also Figure 7 , provides the radiation pattern of the ultra-wideband antenna at 10.5 GHz in an embodiment of the present invention, by Figure 7 It can be seen that the E-plane radiation pattern of the antenna presents directional radiation in the shape of an "8", and the H-plane radiation pattern of the antenna is approximately circular, showing omnidirectional radiation characteristics. The antenna has good omnidirectional radiation characteristics in the entire passband frequency band.

[0040] The above simulation analysis shows that the bandwidth of the antenna of the present invention is 2.8-12.3 GHz, and the working bandwidth fully meets the ultra-wideband frequency band range of 3.1-10.6 GHz. It has good stopband characteristics in the two frequency bands of 3.23-3.7 GHz and 8.01-8.66 GHz, and can simultaneously filter out the electromagnetic interference generated by the two narrowband communication systems of WiMAX (3.3-3.6 GHz) and the International Telecommunication Union (8.01-8.5 GHz), and has basically stable peak gain and omnidirectional radiation characteristics within the passband frequency band, which makes the antenna have greater practical value.

[0041] The ultra-wideband antenna with dual notch characteristics disclosed in the above embodiments has the advantages of miniaturization, simple structure, good radiation characteristics, strong anti-interference ability, stable performance, etc. The monopole antenna structure is used as the radiation patch 20 to achieve the miniaturization of the ultra-wideband antenna. The stopband is generated by introducing the T-shaped branch 22 and etching the U-shaped narrow gap 31, filtering out the interference of the two narrowband signals of WIMAX and the International Telecommunication Union, and realizing the mutual compatibility and cooperative communication between the ultra-wideband system and other narrowband communication systems. In addition, by adjusting the horizontal and vertical lengths of the T-shaped branch 22 and the parameters of the U-shaped narrow gap 31, the center frequency and bandwidth of the notch can be flexibly adjusted, and the notch has the adjustable characteristic. The cut corners on both sides of the rectangle are used, and the semicircular groove 21 structure is dug on the top as the radiation patch 20, and the monopole antenna is used. The small space occupation and easy improvement characteristics of the monopole antenna effectively expand the antenna bandwidth and reduce the antenna size. The semicircular groove 21 is dug out on the radiation patch 20 and the T-shaped branch 22 is introduced, which greatly changes the surface current distribution characteristics of the antenna, increases the surface current path of the antenna, and expands the low-frequency bandwidth of the antenna while generating the notch frequency band. The antenna ground plate of the present invention adopts an improved ground plate 40 structure, and cuts off the triangular corners on both sides of the top of the ground plate, and opens an irregular groove 42 in the middle and upper part. This structure can produce a gradual resonance characteristic, so that the antenna can smoothly transition from one resonance mode to another resonance mode, thereby further improving the antenna performance. In addition, the present invention adopts the method of introducing T-shaped branches 22 and etching U-shaped narrow gaps 31 to produce notch characteristics. The structure is simple, replaces the filter design, reduces the design cost and complexity, is easy to process, and is easy to produce. It adopts a planar structure, is small in size, and has a compact structure, which is easy to integrate with the RF front-end circuit.

[0042] The present invention adopts a monopole antenna structure as a radiation patch, realizes the miniaturization of the ultra-wideband antenna and the simple structure, generates a stopband by introducing T-shaped branches and etching U-shaped narrow gaps, effectively filters out interference from different narrowband signals, and realizes the mutual compatibility and cooperative communication between the ultra-wideband system and other narrowband communication systems. It has the advantages of simple structure, miniaturization, strong anti-interference ability, and good radiation characteristics, has high practical value, and can be applied to a variety of ultra-wideband communication systems.

[0043] The above is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and changes can be made without departing from the principle of the present invention, and these improvements and changes are also regarded as the protection scope of the present invention.

Claims

1. A miniaturized ultra-wideband antenna with dual notch characteristics, comprising a dielectric substrate (10), a radiation patch (20), a microstrip feeder (30) and an improved ground plane (40), characterized in that: The radiation patch (20) and the microstrip feed line (30) are both printed on the front side of the dielectric substrate (10), and the improved ground plate (40) is printed on the back side of the dielectric substrate (10); The radiation patch (20) is a rectangular structure, with first corner cutouts (23) symmetrically arranged on both sides of its bottom, and a semicircular groove (21) dug on its top; The microstrip feed line (30) is connected to the bottom of the radiation patch (20), and second corner cuts are provided on both sides of the connection with the bottom of the radiation patch (20); The improved grounding plate (40) has symmetrically arranged third corner cutouts (41) formed on both sides of the top, and an irregularly shaped groove (42) formed in the middle; The radiation patch (20) has a rectangular structure with cut corners on both sides of the bottom and a semicircular groove (21) dug out at the top. The semicircular groove (21) is dug out on the radiation patch (20) and symmetrical first cut corner portions (23) are formed on both sides of the bottom. The semicircular groove (21) is located at the top of the radiation patch (20), and the first cut corner portion (23) is located at the bottom of the radiation patch (20). A U-shaped narrow gap (31) is etched on the microstrip feed line (30) and extends upward from the middle and lower part of the microstrip feed line (30); The provision of the third cut corner portion (41) can improve the impedance matching characteristics of the antenna, the horizontal length of the third cut corner portion (41) is 3-5 mm, and the vertical length of the third cut corner portion (41) is 3-4 mm; The irregular-shaped groove (42) is located in the upper middle portion of the improved ground plate (40) and is located directly below the microstrip feed line (30). The length of the irregular-shaped groove (42) is 8.5-9.5 mm.

2. The miniaturized ultra-wideband antenna with dual notch characteristics as claimed in claim 1, characterized in that: A T-shaped branch (22) is provided above the semicircular groove (21).

3. The miniaturized ultra-wideband antenna with dual notch characteristics as claimed in claim 2, characterized in that: The T-shaped branch (22) is located at the central axis of the dielectric substrate (10) and is connected to the semicircular groove (21).

4. The miniaturized ultra-wideband antenna with dual notch characteristics as claimed in claim 1, characterized in that: The radius of the semicircular groove (21) is 8.8-9.2 mm.

5. The miniaturized ultra-wideband antenna with dual notch characteristics as claimed in claim 1, characterized in that: The horizontal length of the first chamfered portion (23) is 5.8-6.2 mm, and the vertical length is 8.5-9 mm.

6. The miniaturized ultra-wideband antenna with dual notch characteristics as claimed in claim 2, characterized in that: The horizontal length of the T-shaped branch (22) is 12.5-13.5 mm, and the vertical length is 7.8-8 mm.

7. The miniaturized ultra-wideband antenna with dual notch characteristics as claimed in claim 1, characterized in that: The microstrip feed line (30) is a microstrip feed line with a characteristic impedance of 50Ω, the length of the microstrip feed line (30) is 13-14 mm, and the width is 1.5 mm; The U-shaped narrow gap (31) has a gap width of 0.19 mm.

8. The miniaturized ultra-wideband antenna with dual notch characteristics according to any one of claims 1 to 7, characterized in that: The thickness of the dielectric substrate (10) is 1 mm, and the length and width of the dielectric substrate (10) are 31 mm and 18 mm respectively.

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