阅读说明：本技术 一种具有高效率高增益的双频段电小天线 (dual-band electrically small antenna with high efficiency and high gain ) 是由 彭亮 洪潇 于 2019-09-17 设计创作，主要内容包括：本发明公开一种具有高效率高增益的双频段电小天线。本发明包括介质基板、等效地端、短共面波导、馈电端口、适当延伸的馈电小棒、成对的拓展枝节；在介质基板的正面部分区域铺设金属作为等效地端,接着在等效地端的上边沿中间挖出一定深度的槽作为短共面波导,用来调节天线阻抗匹配,然后从短共面波导处适当延伸出一个馈电小棒,在馈电小棒两侧对称的位置放置成对的SRR结构。该电小天线通过在传统天线上加载成对的SRR结构,一方面减小天线的高度,实现小型化；另一方面克服了传统电小天线低辐射阻抗的缺点,提高了电小天线的辐射效率和增益。(The invention discloses double-frequency band small electric antennas with high efficiency and high gain, which comprise a dielectric substrate, an equivalent ground end, a short coplanar waveguide, a feed port, small feed rods extending properly and paired extension branches, wherein metal is paved on part of the front surface of the dielectric substrate to serve as the equivalent ground end, a groove with certain depth is dug in the middle of the upper edge of the equivalent ground end to serve as the short coplanar waveguide to adjust the impedance matching of the antennas, small feed rods extend out of the short coplanar waveguide properly, and paired SRR structures are arranged at symmetrical positions on two sides of the small feed rods.)

1, double-frequency-band electric small antenna with high efficiency and high gain, which is characterized by comprising a dielectric substrate (1), an equivalent ground end (2), a short coplanar waveguide (6), a feed port (7), a feed small rod (5) which is properly extended and an SRR expansion branch section;

a metal layer is laid at the lower end of the front surface of the dielectric substrate (1), the metal layer is used as an equivalent ground end (2), and the rest area is used as a laying area of the antenna system;

the antenna system mainly comprises two parts, wherein the part is a small feed rod (5) properly extending from a short coplanar waveguide (6), and the part between the equivalent ground end (2) and the small feed rod (5) is used as a feed port (7), and the part is four SRR expansion branches positioned on two sides of the small feed rod (5);

the SRR expansion branch (3-1) and the second SRR expansion branch (3-2) are mirror-symmetrical about the feed small rod (5), and the sizes of the structures are the same;

the third SRR extended branch section (4-1) and the fourth SRR extended branch section (4-2) are in mirror symmetry with respect to the small feed rod (5), and the sizes of the structures are the same;

the SRR expansion branch (3-1) and the third SRR expansion branch (4-1) are both L-shaped structures which are turned over 90 degrees to the right, wherein the end is vertically connected with the edge of the equivalent ground end (2);

the second SRR expansion branch section (3-2) and the fourth SRR expansion branch section are of L-shaped structures after horizontal overturning, and the L-shaped structures are overturned for 90 degrees leftwards, wherein the end is vertically connected with the edge of the equivalent ground end (2);

the third SRR expansion branch (4-1) is positioned at the inner side of the SRR expansion branch (3-1);

the fourth SRR expansion branch (4-2) is positioned at the inner side of the second SRR expansion branch (3-2);

the distance between the SRR expansion branch knot (3-1) and the third SRR expansion branch knot (4-1) which are perpendicular to the equivalent ground end (2) is different from the distance between the SRR expansion branch knot (3-1) and the third SRR expansion branch knot (4-1) which are far away from the equivalent ground end (2);

the distance between the second SRR extended branch knot (3-2) and the fourth SRR extended branch knot (4-2) perpendicular to the equivalent ground end (2) is different from the distance between the second SRR extended branch knot (3-2) and the fourth SRR extended branch knot (4-2) far away from the equivalent ground end (2).

2. Dual-band electrically small antenna with high efficiency and high gain according to claim 1, characterized in that the feed rod (5) is not fixed in shape and mainly acts as a feed to couple energy to the four SRR expansion branches.

3. The dual-band electrically small antenna with high efficiency and high gain as claimed in claim 1, wherein the thickness of the metal layer is 35 μm as required by , and its area size will change the current distribution to affect the impedance matching of the antenna.

4. Dual-band electric small antenna with high efficiency and high gain according to claim 1, characterized in that the length of the feeding small rod (5) outside the equivalent ground end (2) is equal to the height of the SRR extension branch (3-1) and the second SRR extension branch (3-2), and equal to the height of the third SRR extension branch (4-1) and the fourth SRR extension branch (4-2) is not .

5. The dual-band electrically small antenna with high efficiency and high gain according to claim 1, wherein the inductor is introduced into the overall length of the SRR extension branch (3-1) and the second SRR extension branch (3-2), the inductor is introduced into the overall length of the SRR extension branch (3-1) and the second SRR extension branch (3-2) at a distance of to form an SRR structure, and an LC resonance is generated, the SRR structure can significantly reduce the size of the antenna, and the SRR structure is far from metal of the equivalent end (2), which is equivalent to metal strip, which can significantly increase the radiation impedance of the antenna to achieve the purpose of improving the efficiency, and the metal strip is far enough from the equivalent end (2) to not have a large influence on the overall inductance of the antenna, the third SRR extension branch (4-1) and the fourth SRR extension branch (4-2) are introduced into the overall length of the inductor extension branch (4-1), the fourth SRR extension branch (4-352) is far enough to form an SRR equivalent antenna structure, and the SRR extension branch (3-2) and the antenna structure can significantly reduce the overall length of the SRR extension branch (3-2) to form an equivalent antenna structure, which is equivalent to form an SRR resonance structure, and an SRR resonance structure, which is far enough to form an SRR resonance structure, and an equivalent to form an equivalent antenna structure, and an SRR resonance structure, and an equivalent antenna structure, and an equivalent to form an SRR antenna structure, and an equivalent to form an equivalent antenna structure, and an equivalent to form an SRR antenna structure, and an equivalent;

the two pairs of SRR structures enable electromagnetic energy to propagate mainly along the direction vertical to the dielectric substrate (1), so that the gain of the antenna is improved.

Technical Field

The invention belongs to the technical field of wireless communication, and relates to dual-band electrically small antennas with high efficiency and high gain, which are used for improving the radiation efficiency, the radiation resistance and the radiation direction of an on-chip dual-band electrically small antenna.

Background

With the rapid development of communication technology, the volume of communication equipment such as mobile phones becomes smaller and smaller, the development and application of Radio Frequency Identification (RFID) become more mature, and antenna, which is a key element of these applications, is also developing towards miniaturization.

1. The radiation efficiency is low. Since the electrically small antenna has a small electrical size, its radiation resistance will be reduced, and assuming that there is no loss in the antenna itself, it is always possible to eliminate the input reactance component of the antenna by an appropriate method and to convert its resistance to an appropriate value so as to match it with a transmitter or a receiver, thereby effectively performing an energy conversion function. Unfortunately, not only is there thermal loss from the antenna itself, but the matching circuit also introduces losses. These losses are more pronounced when the radiation resistance of the antenna is low, thereby reducing the radiation efficiency of the antenna, and thus for small antennas, low radiation efficiency is a prominent problem.

2. Since the small antenna is equivalent to a capacitor or an inductor and has a low resistance component, i.e., it has a high quality factor Q of , and the Q value is inversely proportional to the bandwidth, the operating band of the small antenna is relatively narrow, which means that the operating band width is also a problem to be considered in designing the small antenna.

The approaches for improving the radiation efficiency and gain of the electrically small antenna are as follows:

1. increasing the radiation resistance, for example introducing metal strips in the antenna structure, but this introduces a certain inductance, causing impedance mismatch;

2. the power is effectively fed to the antenna, and the influence of the change of the object adjacent to the antenna and the ground condition on the antenna is reduced, for example, a balun or a pi-type matching circuit is added at a feeder end, but the cost is increased, the loss is easily brought by a matching stage, and the environment of the antenna in practical application is not ideal.

Disclosure of Invention

The invention aims to overcome the difficulties and the front-view challenges mentioned above, overcome the defects of low radiation impedance and low radiation efficiency of an electrically small antenna, meet the requirements of miniaturization, high gain and high efficiency of an antenna provided by wireless communication equipment, and provide on-chip dual-band electrically small antennas with high radiation impedance, efficiency and gain.

The invention comprises a dielectric substrate (1), an equivalent ground end (2), a short coplanar waveguide (6), a feed port (7), a feed small rod (5) which extends properly and a pair of SRR expansion branches;

a partial blank area is reserved at the upper end of the front surface of the dielectric substrate (1) and is used as a laying area of an antenna system, a metal layer is laid in the remaining lower end area and is used as an equivalent ground end (2), a groove with fixed depth is dug in the middle of the laying area end, close to the antenna system, of the equivalent ground end (2) and is used as a short coplanar waveguide (6), and a proper size is obtained through parameter scanning and is used for adjusting antenna impedance matching;

the antenna system mainly comprises two parts, wherein the part is a small feed rod (5) which properly extends from a short coplanar waveguide (6), the part between the equivalent ground end (2) and the small feed rod (5) is used as a feed port (7), and the part is four SRR expansion branches positioned on two sides of the small feed rod (5).

The SRR expansion branch (3-1) and the second SRR expansion branch (3-2) are mirror-symmetrical about the small feed rod (5), and the structural sizes are the same.

The third SRR extended branch section (4-1) and the fourth SRR extended branch section (4-2) are in mirror symmetry with respect to the small feed rod (5), and the structure size is the same.

The SRR expansion branch (3-1) and the third SRR expansion branch (4-1) are both L-shaped structures which are turned over 90 degrees to the right, wherein the end is vertically connected with the edge of the equivalent ground end (2).

The second SRR expansion branch section (3-2) and the fourth SRR expansion branch section are of L-shaped structures after horizontal overturning, and the L-shaped structures are overturned for 90 degrees leftwards, wherein the end is vertically connected with the edge of the equivalent ground end (2).

The third SRR expansion branch (4-1) is positioned at the inner side of the SRR expansion branch (3-1).

The fourth SRR expansion branch (4-2) is positioned at the inner side of the second SRR expansion branch (3-2).

The distance between the SRR expansion branch knot (3-1) and the third SRR expansion branch knot (4-1) perpendicular to the equivalent ground end (2) is different from the distance between the SRR expansion branch knot (3-1) and the third SRR expansion branch knot (4-1) far away from the equivalent ground end (2).

The distance between the second SRR extended branch knot (3-2) and the fourth SRR extended branch knot (4-2) perpendicular to the equivalent ground end (2) is different from the distance between the second SRR extended branch knot (3-2) and the fourth SRR extended branch knot (4-2) far away from the equivalent ground end (2).

the distance between the SRR expansion branch knot (3-1) and the SRR expansion branch knot (4-1) perpendicular to the equivalent ground end (2) and the distance between the SRR expansion branch knot (3-2) and the SRR expansion branch knot (4-2) perpendicular to the equivalent ground end (2) are both 0.5mm, the capacitance between the expansion branch knots can be introduced when the distances are too close, and the length of section of the expansion branch knot far away from the equivalent ground end (2) needs to be increased when the distances are too far, so that the capacitance between the expansion branch knot and the small feed rod (5) is caused, and impedance mismatching is caused.

the distance between the ends of the SRR expansion branch knot (3-1) and the SRR expansion branch knot (4-1) far away from the equivalent ground end (2) and the distance between the ends of the SRR expansion branch knot (3-2) and the SRR expansion branch knot (4-2) far away from the equivalent ground end (2) are 1.5mm, the capacitance between the expansion branch knots can be introduced when the distances are too close, and the capacitance between the expansion branch knots and the equivalent ground end (2) needs to be increased when the distances are too far, so that impedance mismatching is caused.

The shape of the small feed rod (5) is not fixed, and can be simple straight lines, curves or complex antenna structures, and the small feed rod is mainly used for feeding and coupling energy to four SRR expansion branches.

The metal layer thickness requirement is typically 35 μm, which changes the current distribution by its area size and thus affects the impedance matching of the antenna;

the length L3+ G8-G2 of the small feed rod (5) outside the equivalent ground end (2) is equal to the height W1 of the SRR expansion branch (3-1) and the SRR expansion branch (3-2) of the third SRR expansion branch (4-1) and the SRR expansion branch (4-2) of the fourth SRR expansion branch (4-2) but not equal to 0, the integral length of the SRR expansion branch (3-1) of the th SRR expansion branch (3-1) and the SRR expansion branch (3-2) of the second SRR expansion branch introduces inductance, the capacitive introduction of distance exists between the SRR expansion branch (3-1) of the SRR expansion branch (3-1) and the SRR expansion branch (3-2) of the second SRR expansion branch, so that an SRR high-efficiency structure is formed, an SRR resonance is generated, the size of the SRR structure can be obviously reduced, the SRR structure is far away from sections of the equivalent ground end (2), equivalently, a metal strip is introduced, a is equivalently, the impedance of the SRR expansion branch can be increased to obviously, the SRR expansion branch can be far away from the equivalent ground end, the SRR expansion branch (4) of the SRR expansion branch, the SRR expansion branch can be far away from the equivalent ground end, the equivalent antenna can be far equivalent expansion branch (4) of the SRR expansion branch (4) is not far equivalent antenna, the equivalent expansion branch (4) of the SRR expansion branch can be increased, the equivalent antenna, the equivalent expansion branch (3-equivalent expansion branch can be increased impedance of the equivalent expansion branch can be increased, the equivalent expansion branch (4) of the.

The introduction of the two pairs of SRR structures can limit the propagation of electromagnetic waves in certain directions, so that the antenna can generate the end-fire-like characteristic, electromagnetic energy is mainly propagated along the direction vertical to the dielectric substrate (1), and the gain of the antenna is improved.

The resonance point of the antenna is changed by adjusting the lengths of the SRR expansion branch (3-1), the second SRR expansion branch (3-2), the third SRR expansion branch (4-1), the fourth SRR expansion branch (4-2) and the small feed rod (5), so that the antenna works in a required frequency band;

the feed mode of the antenna can be various, a coaxial feed mode can be adopted, a coplanar waveguide feed mode can also be adopted, a microstrip line feed mode can also be adopted, and the short coplanar waveguide feed adopted by the antenna can achieve a good impedance matching effect on the basis of not increasing an additional matching circuit.

The invention has the beneficial effects that:

the antenna can obviously improve the radiation impedance of the traditional electrically small antenna, so that the radiation efficiency of the traditional electrically small antenna can be improved without an additional impedance matching circuit, the electromagnetic energy radiated by the antenna is mainly propagated along the direction vertical to the dielectric substrate (1), and the gain of the antenna is obviously improved, compared with the traditional electrically small antenna radiating in all directions, because the antenna has a planar structure, the antenna is easy to integrate with a PCB circuit, has a low profile and a simple structure, is easy to process, has low cost, can be produced in batches, and can be widely applied to mobile handheld terminal equipment as .

Drawings

Fig. 1 is a schematic view of the overall structure of an antenna;

FIG. 2 is a dimensioning of the antenna;

fig. 3(a), (b) are a side view and a radiation direction of the antenna, respectively;

table 1 is the specific dimensions of the antenna;

in the figure, 1 is a dielectric substrate, 2 is a metal ground, 3 is a th pair of expansion branches, 3-1 is a th expansion branch, 3-2 is a second expansion branch, 4 is a second pair of expansion branches, 4-1 is a third expansion branch, 4-2 is a fourth expansion branch, 5 is a monopole antenna, 6 is a short coplanar waveguide, 7 is a feed port, and 8 is a radiation direction.

Detailed Description

The steps of the preferred embodiment of the present invention are described in detail below with reference to the accompanying drawings.

As shown in fig. 1 and 2, a metal ground 2 is laid in a region below the front surface of a dielectric substrate 1, the antenna is located in a metal-free ground blank region of the front surface of the dielectric substrate 1, a simplest monopole antenna 5 is adopted, th pairs of expansion branches 3 and 4 th pairs of expansion branches are respectively extended upwards from the left end and the right end of the metal ground 2 along the blank region of the front surface of the dielectric substrate 1, th pairs of expansion branches 3 comprise th expansion branches 3-1 and 3-2 and are in an L-shaped structure turned by 90 degrees to the right, and the 4 th pairs of expansion branches comprise 4-1 th expansion branches and 4-2 and are in an L-shaped structure turned by 90 degrees to the left, the length of the monopole antenna 5 outside the metal ground 2 is equal to the length of the th expansion branch 3, the length of the 4 second pair of expansion branches is not equal to , so that a dual-frequency section is generated, and the th pairs of expansion branches 3 and the 355 are symmetrical to prevent a fixed capacitance distance between the monopole antenna and .

the line widths of the third expanded branch 3-1, the second expanded branch 3-2, the third expanded branch 4-1 and the fourth expanded branch 4-2 are the same.

The antenna adopts a short coplanar waveguide feed mode to achieve good impedance matching.

As shown in Table 1, the specific dimensions of the antenna structure are listed

TABLE 1

The antenna modeling simulation of the method is carried out in CST, the relevant size of the structure is shown in figure 2, the antenna works in a required dual-band by adjusting W1 and L1 of the extended branch 3 and W3 and L2 of the extended branch 4, and the impedance matching of the antenna meets the requirement by adjusting the distances G6 and G5 from the extended branches 3 and 4 to the monopole antenna 5.

According to the method, the L-shaped metal strip is loaded on the original antenna, so that the height of the antenna is obviously reduced, the radiation impedance of the antenna is improved, and electromagnetic waves can only be transmitted along fixed directions, so that the radiation efficiency and the gain of the antenna are improved.

The antenna has the characteristics of low section, plane printing, simple structure and the like, is convenient to integrate with a circuit, is easy to process, has low cost, can be tested by connecting an SMA radio frequency connector with the impedance of 50 ohms, and is simple to operate, so that can be widely pushed to for use.

The antenna designed by the invention solves the contradiction between high antenna radiation efficiency and small antenna size, effectively improves the antenna radiation efficiency and simultaneously improves the gain.

Accordingly, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all modifications which come within the spirit and scope of the appended claims.