阅读说明：本技术 应用于uhf频段的加载铁氧体介质的小型化双频天线 (Miniaturized dual-frequency antenna applied to UHF frequency band and loaded with ferrite medium ) 是由 程简 李永伟 冯全源 于 2021-08-26 设计创作，主要内容包括：本发明公开了一种应用于UHF频段的加载铁氧体介质的小型化双频天线,属于小型化双频天线设计技术领域,包括设于天线中间层的天线基板、设于天线顶层外围的第一方形谐振环、设于天线顶层内中间的第二方形谐振环、设于天线顶层中心的由短路线连接的矩形贴片、设于天线底层外围的接地方形环和设于天线底层中心并与馈线成45°角的H形带隙结构；所述第一方形谐振环和第二方形谐振环之间远离馈线侧的间隙处加载有矩形Co-(2)W型六角铁氧体介质；本方案提供的加载铁氧体介质的小型化双频天线解决了加载铁氧体的小型化双频天线设计实现的问题,该天线可广泛应用于ISM(915MHz)/GSM900/UMTS的无线设备。(The invention discloses a miniaturized dual-frequency antenna applied to a UHF frequency band and loaded with ferrite medium, belonging to the technical field of miniaturized dual-frequency antenna design, comprising an antenna substrate arranged in the middle layer of the antenna, a first square resonant ring arranged on the periphery of the top layer of the antenna, a second square resonant ring arranged in the middle of the top layer of the antenna, a rectangular patch arranged in the center of the top layer of the antenna and connected by a short circuit line, a grounding square ring arranged on the periphery of the bottom layer of the antenna and an H-shaped band gap structure arranged in the center of the bottom layer of the antenna and forming an angle of 45 degrees with a feeder line; a rectangular Co is loaded at a gap between the first square resonance ring and the second square resonance ring far away from the feeder side 2 W-type hexaferrite media; the loading ferrite provided by the schemeThe miniaturized dual-frequency antenna of the bulk medium solves the problem of design realization of the miniaturized dual-frequency antenna loaded with ferrite, and can be widely applied to ISM (915MHz)/GSM900/UMTS wireless equipment.)

1. A miniaturized dual-band antenna loaded with ferrite medium and applied to UHF frequency band is characterized by comprising an antenna substrate (1) arranged in the middle layer of the antenna, a first square resonance ring (2) arranged on the periphery of the top layer of the antenna, a second square resonance ring (3) arranged in the middle of the top layer of the antenna, a rectangular patch (5) arranged in the center of the top layer of the antenna and connected by a short circuit line (4), a grounding square ring (6) arranged on the periphery of the bottom layer of the antenna and an H-shaped band gap structure (8) arranged in the center of the bottom layer of the antenna and forming an angle of 45 degrees with a feeder line (7);

a rectangular Co is loaded at the gap between the first square resonance ring (2) and the second square resonance ring (3) far away from the feeder (7)₂And W-type hexaferrite medium (9).

2. The miniaturized dual-band antenna applied to UHF band and loaded with ferrite medium as claimed in claim 1, wherein said antenna substrate (1) is made of FR4 epoxy glass cloth laminate with length, width and thickness h of 50mm x 1.6mm respectively, and the dielectric constant of said FR4 epoxy glass cloth laminate is 4.4, the dielectric loss is 0.02, wherein the length and width of the antenna substrate (1) are the same as the outer width W of said grounding square ring (6).

3. The miniaturized dual-band antenna loaded with ferrite medium for UHF band as claimed in claim 1, wherein the miniaturized dual-band antenna comprises the following structural parameters:

the width W of the outer side of the grounding square ring (6) is 50 mm;

the rectangle Co₂Length L of W-type hexaferrite medium (9)_FeIs 33 mm;

the rectangle Co₂Width W of W-type hexaferrite medium (9)_FeIs 7 mm;

the outer side of the first square resonance ring (2) is long L_sr1Is 34 mm;

the second partyThe outside length L of the ring resonator (3)_sr228.6 mm;

the ring width d of the first square resonance ring (2) is 1.5 mm;

the width W of the short-circuit line (4)_StIs 1.5 mm;

the length L of the feeder line (7)_f10.7 mm;

the width W of the feeder line (7)_fIs 1.5 mm;

the ring width W of the grounding square ring (6)_srIs 5 mm;

the length L of the rectangular patch (5)_pIs 22.6 mm;

the width W of the gap between the first square resonance ring (2) and the second square resonance ring (3)_s1Is 1.2 mm;

the width W of the gap between the second square resonance ring and the rectangular patch (5)_s2Is 1.7 mm;

the length L of the H-shaped band gap structure (8)_HIs 18 mm;

the strip line width W of the H-shaped band gap structure (8)_HIs 1 mm;

the length L of the middle connecting section of the H-shaped band gap structure (8)_hIs 7 mm.

4. The miniaturized dual-band antenna loaded with ferrite medium for UHF band according to claim 1 wherein the grounded square ring (6) is used to generate an Ant1 antenna with bandwidth of 1.04 GHz.

5. The miniaturized dual-band antenna loaded with ferrite medium applied to UHF band as claimed in claim 4, wherein the grounding square ring (6) is added with H-shaped band gap structure (8) to form an Ant2 antenna; the working frequency bands of the Ant2 antenna are 190MHz and 420MHz respectively.

6. The miniaturized dual-band antenna loaded with ferrite medium for UHF band as claimed in claim 1, wherein said rectangular Co is₂The W-type hexaferrite medium (9) has the thickness of 0.6mm and the relative dielectric constant of 14.

Technical Field

The invention belongs to the technical field of miniaturized dual-frequency antenna design, and particularly relates to a miniaturized dual-frequency antenna loaded with ferrite media and applied to a UHF frequency band.

Background

With the development of 5G communication, the integration level of devices is higher and higher, a wireless device often needs to integrate and be compatible with a wireless system with multiple frequency bands, and in order to adapt to and solve the problem that the device works in multiple frequency bands, many research groups have proposed different solutions: some schemes propose to realize that wireless equipment works in multiple frequency bands by designing an MIMO antenna, however, a MIMO antenna system cannot be applied to all wireless equipment, especially to the application with strict antenna space; some solutions have been proposed for broadband antennas, however, the broadband technology implementation of miniaturized low profile planar antennas is difficult. Therefore, in order to fully utilize the spectrum resources and satisfy the requirement of miniaturization, the multi-frequency antenna technology is an excellent solution. The multi-frequency antenna technology has been the focus of research in various groups of subjects. A certain scheme provides a miniaturized multi-frequency circularly polarized antenna loaded with a resonance ring SRR and paved with copper wires, and the antenna can play roles in expanding bandwidth, generating resonance frequency, changing radiation polarization and the like through the loading of an SRR structure; in another scheme, a better return loss characteristic is realized by adopting the annular monopole antenna of the coupling inductance capacitance ELC metamaterial unit; in another scheme, a hexagonal complementary split ring resonator is loaded, so that the antenna generates a new resonant frequency; in another scheme, the combination of various structures can generate the characteristics of multiple frequencies, and the resonance of the antenna can be influenced by the change of the floor; in another scheme, the characteristic that the antenna can realize multi-frequency circular polarization by using an SRR structure on the floor is shown; in another scheme, the super-surface MS artificial floor formed by loading the resonant rings can realize the dual-frequency characteristic of the antenna. The research results can conclude that loading the SRR and MS structures is a good method for realizing the multi-frequency antenna.

Similarly, with the rapid development of circuit integration, the size of wireless communication devices is becoming smaller and smaller, leaving less and less space for antennas. Existing miniaturized antennas have been difficult to meet the space provided by increasingly highly integrated devices. The dielectric material loading method is a useful and promising technology, and can effectively improve the performance of the antenna. Magnetic and dielectric properties are two major physical properties used by many electronic components. In the past, research on miniaturization of microwave devices relatively focuses on innovation of device structures and advanced manufacturing and packaging technologies, and more focuses on new high-performance materials; nowadays, ferrite having both dielectric and magnetic properties is of interest. At present, the research on the miniaturization of the antenna by improving the structure has reached a bottleneck, the research on the miniaturization of the antenna by using an electromagnetic medium becomes more and more important, and the research on the high-frequency magnetic dielectric property of the ferrite loaded antenna has an important significance.

Disclosure of Invention

Aiming at the defects in the prior art, the miniaturized dual-frequency antenna loaded with the ferrite medium applied to the UHF frequency band solves the problem of design and implementation of the miniaturized dual-frequency antenna loaded with the ferrite.

In order to achieve the purpose of the invention, the invention adopts the technical scheme that:

the invention provides a miniaturized dual-frequency antenna loaded with ferrite medium and applied to UHF frequency band, which comprises an antenna substrate arranged in an antenna middle layer, a first square resonance ring arranged on the periphery of an antenna top layer, a second square resonance ring arranged in the middle of the antenna top layer, a rectangular patch arranged in the center of the antenna top layer and connected by a short circuit line, a grounding square ring arranged on the periphery of an antenna bottom layer and an H-shaped metal band gap structure arranged in the center of the antenna bottom layer and forming an angle of 45 degrees with a feeder line, wherein the grounding square ring is arranged on the periphery of the antenna bottom layer;

a rectangular Co is loaded at a gap between the first square resonance ring and the second square resonance ring far away from the feeder side₂W-type hexaferrite medium.

The invention has the beneficial effects that: the miniaturized dual-frequency antenna loaded with the ferrite medium and applied to the UHF frequency band, provided by the invention, has the advantages that the structure of two square resonance rings is adopted on the top layer of the antenna, the current length of the antenna is prolonged, the low-frequency working frequency band of the antenna is shifted to lower frequency, the working frequency band of the antenna is divided into two parts of 190Mhz (1.48-1.67GHz) and 420MHz (2.12-2.64GHz), and the H-shaped band gap structure forming an angle of 45 degrees with a feeder line is adopted on the bottom layer of the antenna to play a role of an Electromagnetic Band Gap (EBG) so as to better isolate the two working frequency bands of the antenna, so that the antenna provided by the scheme is added with the structure of two square resonance ringsLoaded with Co₂When the W-type hexagonal ferrite is used, the low-frequency operating band of the antenna moves to a lower frequency band, which is equivalent to the miniaturization of the antenna, the-10 d operating bands of the antenna are 890-970 MHz (80MHz, 925MHz) and 1.87-2.24 GHz (370MHz, 2.175GHz), and the antenna can be widely applied to ISM (915MHz)/GSM900/UMTS wireless equipment.

Furthermore, the antenna substrate is an FR4 epoxy glass cloth laminated board with a length, a width and a thickness h of 50mm × 50mm × 1.6mm, and the FR4 epoxy glass cloth laminated board has a dielectric constant of 4.4 and a dielectric loss of 0.02, wherein the length and the width of the antenna substrate are the same as the outer width W of the grounding square ring. .

The beneficial effect of adopting the further scheme is as follows: the antenna substrate is small in size, and a laminated product formed by hot-pressing the FR 4-grade epoxy glass cloth laminated board by taking epoxy resin as an adhesive is high in mechanical strength at high temperature and still has stable electrical performance in a high-humidity environment.

Further, the miniaturized dual-band antenna comprises the following structural parameters:

the width W of the outer side of the grounding square ring is 50 mm;

the rectangle Co₂Length L of W-type hexaferrite medium_FeIs 33 mm;

the rectangle Co₂Width W of W-type hexaferrite medium_FeIs 7 mm;

the outer side of the first square resonance ring is long L_sr1Is 34 mm;

the outer side of the second square resonant ring is long L_sr228.6 mm;

the ring width d of the first square resonance ring is 1.5 mm;

width W of the short-circuit line_StIs 1.5 mm;

length L of the feeder line_f10.7 mm;

width W of the feed line_fIs 1.5 mm;

the ring width W of the grounding square ring_srIs 5 mm;

the length L of the H-shaped band gap structure_HIs 18 mm;

length L of the rectangular patch_pIs 22.6 mm;

the width W of the gap between the first square resonance ring and the second square resonance ring_s1Is 1.2 mm;

the width W of the gap between the second square resonance ring and the rectangular patch_s2Is 1.7 mm;

the width W of the strip line of the H-shaped band gap structure_HIs 1 mm;

the length L of the middle connecting section of the H-shaped band gap structure_hIs 7 mm.

The beneficial effect of adopting the further scheme is as follows: the design parameters realize good double-frequency response of the antenna in two working frequency bands of 190MHz (1.48-1.67GHz) and 420MHz (2.12-2.64GHz), so that the antenna has better selectivity and out-of-band rejection, and the miniaturization of the antenna is realized.

Further, the ground square ring is used to generate an Ant1 antenna with a bandwidth of 1.04 GHz.

The beneficial effect of adopting the further scheme is as follows: the method is used for distinguishing the electromagnetic band gap action of the H-shaped metal strip line before and after the H-shaped band gap structure is added.

Further, an H-shaped band gap structure is added in the grounding square ring to form an Ant2 antenna; the working frequency ranges of the Ant2 antenna are 190MHz and 420MHz respectively;

the beneficial effect of adopting the further scheme is as follows: the Ant2 antenna is suitable for GPS 1575.42MHz, ISM 2.4GHz and LTE 2300 MHz.

Further, the rectangular Co₂The W-type hexaferrite medium has a thickness of 0.6mm and a relative dielectric constant of 14.

The beneficial effect of adopting the further scheme is as follows: the rectangle Co₂The relative dielectric constant of the W-type hexaferrite medium is stable along with the increase of frequency, the magnetic conductivity of the W-type hexaferrite medium is sharply reduced along with the increase of frequency, the resonant frequency of the antenna in a low-frequency working frequency band is reduced along with the increase of the magnetic conductivity, and the current of the antenna is concentrated in a rectangular Co₂At the position of W-type hexagonal ferrite, the antenna peak gain is stable, and Co is loaded₂Radiation performance of W-type hexaferrite antennaMore stable, Co loading on the antenna₂In the case of W-type hexaferrite, the low-frequency operating band of the antenna will shift to a lower frequency band, which is equivalent to the miniaturization of the antenna.

Drawings

Fig. 1(a) is a top layer structure diagram of a miniaturized dual-band antenna loaded with ferrite medium and applied to UHF band in the embodiment of the present invention.

Fig. 1(b) is a bottom structure diagram of a miniaturized dual-band antenna loaded with ferrite medium and applied to UHF band in the embodiment of the present invention.

Fig. 1(c) is a side structure diagram of a miniaturized dual-band antenna loaded with ferrite medium and applied to UHF band in the embodiment of the present invention.

Fig. 2(a) is a geometric parameter diagram of a top layer structure of a miniaturized dual-band antenna loaded with ferrite medium applied to UHF band in the embodiment of the present invention.

Fig. 2(b) is a geometric parameter diagram of the bottom structure of the miniaturized dual-band antenna loaded with ferrite medium applied to UHF band in the embodiment of the present invention.

Fig. 2(c) is a side structural geometric parameter diagram of a miniaturized dual-band antenna loaded with ferrite medium applied to UHF band in the embodiment of the present invention.

Fig. 3(a) is a schematic diagram of an Ant1 antenna in an embodiment of the present invention.

Fig. 3(b) is a schematic diagram of an Ant2 antenna in the embodiment of the present invention.

Fig. 3(c) is a diagram showing simulation S11 results of the Ant2 antenna in the embodiment of the present invention.

Fig. 3(d) is a diagram showing simulation S11 results of the Ant2 antenna in the embodiment of the present invention.

FIG. 4(a) is a drawing showing a drawing of example C_O2The dielectric constant and the magnetic permeability of the W-type hexaferrite medium are shown schematically.

Fig. 4(b) is a graph comparing the simulation S11 of the antenna loaded with no ferrite medium and the antenna loaded with ferrite of different permeability in the embodiment of the present invention.

FIG. 5 shows loading of Co in an embodiment of the present invention₂Simulation and test S11 result chart of the antenna of W type hexaferrite medium.

Fig. 6(a) is a measured E-plane, 0.925GHz 2D radiation pattern for an antenna in an embodiment of the present invention.

Fig. 6(b) is a measured E-plane, 2D radiation pattern at 2.175GHz for an antenna in an embodiment of the present invention.

Fig. 6(c) shows the measured H-plane, 0.925GHz 2D radiation pattern of the antenna of an embodiment of the present invention.

Fig. 6(D) is a measured H-plane, 2D radiation pattern at 2.175GHz for an antenna in an embodiment of the present invention.

FIG. 7 shows an embodiment of the present invention in which the antenna is loaded with Co₂W-type hexaferrite medium and no Co loading₂And (3) a comparison graph of the actually measured gain of the W-type hexaferrite medium.

Wherein: 1. an antenna substrate; 2. a first square resonant ring; 3. a second square resonant ring; 4. short-circuit lines; 5. rectangular paster; 6. a grounded square ring; 7. a feeder line; 8. an H-shaped band gap structure; 9. rectangle C_O2W-type hexaferrite medium.

Detailed Description

The following description of the embodiments of the present invention is provided to facilitate the understanding of the present invention by those skilled in the art, but it should be understood that the present invention is not limited to the scope of the embodiments, and it will be apparent to those skilled in the art that various changes may be made without departing from the spirit and scope of the invention as defined and defined in the appended claims, and all matters produced by the invention using the inventive concept are protected.

As shown in fig. 1(a), 1(b) and 1(c), in one embodiment of the present invention, the present invention provides a miniaturized dual-band antenna loaded with ferrite medium for UHF band, which includes an antenna substrate 1 disposed in the middle layer of the antenna, a first square resonant ring 2 disposed on the periphery of the top layer of the antenna, a second square resonant ring 3 disposed in the middle of the top layer of the antenna, a rectangular patch 5 connected by a short-circuit line 4 disposed in the center of the top layer of the antenna, a ground square ring 6 disposed on the periphery of the bottom layer of the antenna, and an H-shaped bandgap structure 8 disposed in the center of the bottom layer of the antenna and forming an angle of 45 ° with a feeder line 7;

the first square resonance ring 2 and the second square resonance ring 3 are far away from each otherA rectangular Co is loaded at the clearance from the feeder line 7 side₂A W-type hexaferrite medium 9, wherein Patch represents the top layer of the antenna, Substrate represents the Substrate of the antenna, Ground represents the bottom layer of the antenna, and Ferrite represents C_O2W-type hexaferrite medium.

The antenna substrate 1 is an FR4 epoxy glass cloth laminated board with the length, width and thickness h of 50mm multiplied by 1.6mm respectively, the dielectric constant of the FR4 epoxy glass cloth laminated board is 4.4, the dielectric loss is 0.02, and the length and width of the antenna substrate (1) are the same as the width W of the outer side of the grounding square ring (6);

the antenna substrate 1 is small in size, and a laminated product formed by hot-pressing an FR 4-grade epoxy glass cloth laminated board by using epoxy resin as an adhesive has high mechanical strength at high temperature and stable electrical performance in a high-humidity environment.

As shown in fig. 2(a), 2(b) and 2(c), the miniaturized dual-band antenna includes the following structural parameters:

the width W of the outer side of the grounding square ring 6 is 50 mm;

the rectangle Co₂Length L of W-type hexaferrite medium 9_FeIs 33 mm;

the rectangle Co₂Width W of W-type hexaferrite medium 9_FeIs 7 mm;

the outside length L of the first square resonance ring 2_sr1Is 34 mm;

the outside length L of the second square resonance ring 3_sr228.6 mm;

the ring width d of the first square resonance ring 2 is 1.5 mm;

the width W of the short-circuit line 4_StIs 1.5 mm;

the length L of the feeder line 7_f10.7 mm;

width W of the feed line 7_fIs 1.5 mm;

the ring width W of the grounding square ring 6_srIs 5 mm;

the length L of the H-shaped bandgap structure 8_HIs 18 mm;

length L of the rectangular patch 5_pIs 22.6 mm;

the width W of the gap between the first square resonance ring 2 and the second square resonance ring 3_s1Is 1.2 mm;

the width W of the gap between the second square resonance ring and the rectangular patch 5_s2Is 1.7 mm;

the strip line width W of the H-shaped band gap structure 8_HIs 1 mm;

the length L of the middle connecting section of the H-shaped band gap structure 8_hIs 7 mm;

the design parameters realize good double-frequency response of the antenna in two working frequency bands of 190MHz (1.48-1.67GHz) and 420MHz (2.12-2.64GHz), so that the antenna has better selectivity and out-of-band rejection, and the miniaturization of the antenna is realized.

The miniaturized dual-frequency antenna comprises the following parameter comparison table of structural parameters as shown in the table I:

TABLE 1

Parameter(s)	Unit: mm is	Parameter(s)	Unit: mm is
				W	50	Wf	1.5
H	1.6	Wsrt	5
				LFe	33	LH	18
WFe	7	Lp	22.6
				Lsr	34	Ws1	1.2
Lsr2	28.6	Ws2	1.7
				d	1.5	WH	1
WSt	1.5	Lh	7
				Lf	10.7

The grounding square ring 6 is used for generating an Ant1 antenna with the bandwidth of 1.04 GHz;

the Anti1 antenna is used to distinguish the electromagnetic bandgap effect of the H-shaped metal strip line before and after the H-shaped bandgap structure 8 is added.

An H-shaped band gap structure 8 is added in the grounding square ring 6 to form an Ant2 antenna; the working frequency bands of the Ant2 antenna are 190MHz and 420MHz respectively.

The rectangle Co₂The thickness of the W-type hexaferrite medium 9 is 0.6mm, and the relative dielectric constant is 14; the rectangle Co₂The relative dielectric constant of the W-type hexaferrite medium 9 is stable along with the change of the frequency, the magnetic permeability of the W-type hexaferrite medium is sharply reduced along with the increase of the frequency, the resonant frequency of the antenna in a low-frequency working frequency band is reduced along with the increase of the magnetic permeability, and the current of the antenna is concentrated in the rectangle Co₂At the position of W-type hexagonal ferrite, the antenna peak gain is stable, and Co is loaded₂The antenna of the W-shaped hexaferrite has more stable radiation performance, and Co is loaded on the antenna₂In the case of W-type hexaferrite, the low-frequency operating band of the antenna will shift to a lower frequency band, which is equivalent to the miniaturization of the antenna.

As shown in fig. 3(a), fig. 3(b), fig. 3(c) and fig. 3(d), in another embodiment of the present invention, the antenna Ant1 is implemented by using the grounding square ring 6 and the feeder 7, and an antenna with an operating bandwidth of 1.04GHz (1.6-2.64GHz) can be generated; an Ant2 antenna is realized by adopting a grounding square ring 6, a feeder 7 and an H-shaped band gap structure 8 forming an angle of 45 degrees with the feeder, the working frequency band of the Ant2 is divided into two parts of 190MHz (1.48-1.67GHz) and 420MHz (2.12-2.64GHz), the H-shaped band gap structure 8 plays a role of an Electromagnetic Band Gap (EBG), the EBG structure is optimized to better isolate two working frequency bands of the antenna, and the simulation S11 result of the Ant1 antenna and the Ant2 antenna shows that the Ant2 antenna is suitable for application scenes such as GPS 1575.42MHz, ISM 2.4GHz and LTE 2300(2135 and 2400MHz) and has wide practical application requirements.

In another embodiment of the present invention, as shown in fig. 4(a), the present invention uses a Keysight material measurement suite to measure the electromagnetic parameters of the ferrite, the dielectric constant of which is relatively stable with increasing frequency, but the permeability of which is sharply reduced with increasing frequency, therefore, the ferrite load should have a large influence on the low-frequency operating band of the antenna;

as shown in FIG. 4(b), the present solution adopts ferrite with the same dielectric constant and different permeability to be loaded on the antenna, and for the simulation of the antenna S11, only the permeability of the ferrite is changed (cut off to 1.5GHz) in the simulation, and as the permeability increases, the resonant frequency of the antenna in the low-frequency operating frequency band moves to the left, so that according to the simulation result, Co is loaded on the miniaturized dual-frequency antenna loaded with ferrite medium applied to UHF frequency band, which is proposed by the present invention₂When the W-shaped hexaferrite is used, the low-frequency working frequency band of the antenna moves to a lower frequency band, which is equivalent to the miniaturization of the antenna;

as shown in fig. 5, a comparison graph of simulation and actual measurement S11 results of the miniaturized dual-band antenna loaded with ferrite medium applied to UHF band proposed by the present invention can be obtained, the actual measurement performance is very similar to the simulation result, and the error between the simulation result and the test result is caused by the processing technology and the test environment.

As shown in fig. 6(a) and 6(b), in another embodiment of the present invention, in order to investigate the influence of ferrite loading on the radiation characteristics of the antenna, the antenna current distribution after the antenna is loaded with ferrite is compared, and as can be seen from comparing fig. 6(a) and 6(b), when ferrite is loaded, the current of the antenna adopting the structure is concentrated near the ferrite, and as can be seen from comparing fig. 6(c) and 6(d), the influence of ferrite loading on the antenna is insignificant, i.e., the ferrite loading mainly has a more significant influence on the low frequency band of the antenna, at around 2.175 GHz.

In another embodiment of the present invention, as shown in fig. 7, the miniaturized dual-band antenna loaded with ferrite medium applied to UHF band provided in the present invention is tested for peak gain, and the test results are compared to find that Co is loaded₂The antenna of W-shaped hexaferrite has more stable radiation performance and can be matched with the existing multibandThe antenna has smaller size and reasonable impedance bandwidth.