阅读说明：本技术 一种多波段可重构微带天线 (Multi-band reconfigurable microstrip antenna ) 是由 韩可 叶倪军 刘义彬 王钰程 于 2021-07-30 设计创作，主要内容包括：本发明提供一种多波段可重构微带天线,在传统截角天线的基础上进行改进,引入RF MEMS开关控制各截角贴片与主贴片的通断,使得在改变表面电流路径方向的同时改变平均工作电流路径的长度,从而在K波段以及Ka波段实现频率的可重构,大幅度提高了可重构微带天线的通用性和集成度,基本覆盖了从20GHz到40GHz的大部分频段。(The invention provides a multiband reconfigurable microstrip antenna which is improved on the basis of the traditional truncated-angle antenna, and an RF MEMS switch is introduced to control the on-off of each truncated-angle patch and a main patch, so that the length of an average working current path is changed while the direction of a surface current path is changed, the frequency reconfiguration is realized in a K wave band and a Ka wave band, the universality and the integration degree of the reconfigurable microstrip antenna are greatly improved, and most frequency bands from 20GHz to 40GHz are basically covered.)

1. A multi-band reconfigurable microstrip antenna, comprising:

a metal ground as a substrate for maintaining a common ground area voltage equipotential;

a substrate disposed above the metal ground for carrying an antenna structure;

the radiation patch is arranged on the substrate, the radiation patch is rectangular, the two right angles at the first end of the radiation patch in the length direction are divided into two first-class truncated corner patches, the two right angles at the second end of the radiation patch in the length direction are divided into two second-class truncated corner patches, the rest part of the radiation patch is a main patch, and the lengths of the inclined sides of the first-class truncated corner patch and the second-class truncated corner patches are different; each first-type truncated-angle patch and each second-type truncated-angle patch are respectively connected with the main patch through one RF MEMS switch, and the emission frequency is reconstructed through the on-off combination of the RF MEMS switches;

and the feed microstrip line is connected with the main patch and used for feeding.

2. The multiband reconfigurable microstrip antenna of claim 1, wherein the RF MEMS switch comprises:

the first switch matching microstrip line and the second switch matching microstrip line are respectively arranged on two sides and used for providing impedance matching;

a switch anchor region disposed on the first switch-matched microstrip line or the second switch-matched microstrip line;

the first side of the switch cantilever beam is connected and fixed with the switch anchor area, and the second side of the switch cantilever beam is suspended;

and the pull-down electrode is arranged at the bottom of the switch cantilever beam, adsorbs the switch cantilever beam and conducts the first switch matching microstrip line or the second switch matching microstrip line under the condition of loading direct current.

3. The multiband reconfigurable microstrip antenna of claim 2, wherein the metal ground is aluminum, the substrate is quartz glass, and the switch cantilever is the same material as the radiating patch.

4. The multiband reconfigurable microstrip antenna of claim 1, wherein the primary patch further has an antenna prototype port for collecting impedance information of the antenna structure during operation.

5. The multiband reconfigurable microstrip antenna of claim 1, wherein the feed microstrip line is fed using a T-junction microstrip power divider.

6. The multiband reconfigurable microstrip antenna of claim 1, wherein the first and second truncated patch types are isosceles right triangles.

7. The multiband reconfigurable microstrip antenna of claim 6, wherein the radiating patch has a thickness of 1 ± 0.5 μm and a length of 6 ± 0.01mm in width; the length of the radiation patch is 4 +/-0.01 mm, and the width of the length of the radiation patch is 4 +/-0.01 mm; the length of the right-angle side of the first type of truncated patch is 1.5 +/-0.01 mm; the length of the right-angle side of the second type of truncated patch is 0.8 +/-0.01 mm.

8. The multiband reconfigurable microstrip antenna of claim 7, wherein the feed microstrip line has a length of 0.5 ± 0.01mm and a width of 0.24 ± 0.01 mm; the length of the RF MEMS switch is 0.25 +/-0.01 mm, and the width of the RF MEMS switch is 0.15 +/-0.01 mm.

9. The multiband reconfigurable microstrip antenna of claim 8 wherein the metallic ground and the substrate have a length of 5.5 ± 0.01mm and a width of 6 ± 0.01 mm; the thickness of the metal ground is 1 +/-0.5 mu m; the thickness of the substrate is 0.4 +/-0.01 mm.

10. The multiband reconfigurable microstrip antenna of claim 1, wherein each RF MEMS switch is connected to a controller module, and the on-off combination of each RF MEMS switch is automatically controlled by the controller module to adjust the transmission frequency.

Technical Field

The invention relates to the technical field of microstrip antennas, in particular to a multiband reconfigurable microstrip antenna.

Background

The rapid evolution of the mobile internet has made miniaturization and integration of various communication devices an important current trend. In various application scenarios, antenna designs are more and more prone to achieve larger capacity and more reliable data communication in a smaller design space, and therefore, the demand for reconfigurable antennas is higher and higher.

The reconfigurable antenna can realize the radiation of a plurality of frequency bands, a plurality of polarization forms and different directional diagrams based on a single antenna, and therefore the reconfigurable antenna mainly comprises a polarization reconfigurable antenna, a frequency reconfigurable antenna and a directional diagram reconfigurable antenna. In the prior art, the purpose of frequency reconfiguration is achieved by changing the effective resonance length of an antenna, designing some microstrip branch type antennas or slot antennas and loading pin diode switches on the antennas or slot antennas to control the length of an average working current path of surface current. The impedance matching characteristic of the antenna can also be changed by loading a variable reactance element or changing the reactance value of the antenna by a certain method and means, for example, loading a varactor diode or an adjustable MEMS (Micro-Electro-Mechanical System) resonator on the antenna, so as to realize the continuous adjustment of the frequency.

However, the existing multiband frequency reconfigurable antenna has the problems of low frequency (mostly concentrated on Sub-6 band, namely 450MHz-6GHz) and small frequency coverage spectrum range of reconfigurable frequency. With the increasing popularization and application of 5G, many spectrum resources in the millimeter wave band are often far apart and distributed in the K band (i.e., 12 to 18GHz) and the Ka band (i.e., 26.5 to 40 GHz). At this time, the conventional frequency reconfigurable antenna often needs to satisfy the transmission and reception of a plurality of frequency bands by increasing the number of antennas, so that the volume of a communication system is large, and the problem of power consumption is increasingly highlighted.

Disclosure of Invention

The embodiment of the invention provides a multiband reconfigurable microstrip antenna, which is used for eliminating or improving one or more defects in the prior art, realizing multi-frequency reconfiguration aiming at a K wave band and a Ka wave band and solving the problems of large volume and high power consumption of a communication system.

The technical scheme of the invention is as follows:

the invention provides a multiband reconfigurable microstrip antenna, comprising:

a metal ground as a substrate for maintaining a common ground area voltage equipotential;

a substrate disposed above the metal ground for carrying an antenna structure;

the radiation patch is arranged on the substrate, the radiation patch is rectangular, the two right angles at the first end of the radiation patch in the length direction are divided into two first-class truncated corner patches, the two right angles at the second end of the radiation patch in the length direction are divided into two second-class truncated corner patches, the rest part of the radiation patch is a main patch, and the lengths of the inclined sides of the first-class truncated corner patch and the second-class truncated corner patches are different; each first-type truncated-angle patch and each second-type truncated-angle patch are respectively connected with the main patch through an RF MEMS (radio frequency micro-electro-mechanical system) switch, and the emission frequency is reconstructed through the on-off combination of the RF MEMS switches;

and the feed microstrip line is connected with the main patch and used for feeding.

In some embodiments, the RF MEMS switch comprises:

the first switch matching microstrip line and the second switch matching microstrip line are respectively arranged on two sides and used for providing impedance matching;

a switch anchor region disposed on the first switch-matched microstrip line or the second switch-matched microstrip line;

the first side of the switch cantilever beam is connected and fixed with the switch anchor area, and the second side of the switch cantilever beam is suspended;

and the pull-down electrode is arranged at the bottom of the switch cantilever beam, adsorbs the switch cantilever beam and conducts the first switch matching microstrip line or the second switch matching microstrip line under the condition of loading direct current.

In some embodiments, the metal ground is aluminum, the substrate is quartz glass, and the switch cantilever is the same as the radiation patch.

In some embodiments, an antenna prototype port is further disposed on the main patch for collecting impedance information of the antenna structure during operation.

In some embodiments, the feed microstrip line is fed by using a T-junction microstrip power divider.

In some embodiments, the first and second types of truncated tiles are isosceles right triangles.

In some embodiments, the thickness of the radiation patch is 1 ± 0.5 μm, and the width of the length of the radiation patch is 6 ± 0.01 mm; the length of the radiation patch is 4 +/-0.01 mm, and the width of the length of the radiation patch is 4 +/-0.01 mm; the length of the right-angle side of the first type of truncated patch is 1.5 +/-0.01 mm; the length of the right-angle side of the second type of truncated patch is 0.8 +/-0.01 mm.

In some embodiments, the length of the feed microstrip line is 0.5 ± 0.01mm, and the width is 0.24 ± 0.01 mm; the length of the RF MEMS switch is 0.25 +/-0.01 mm, and the width of the RF MEMS switch is 0.15 +/-0.01 mm.

In some embodiments, the metal ground and the substrate have a length of 5.5 ± 0.01mm and a width of 6 ± 0.01 mm; the thickness of the metal ground is 1 +/-0.5 mu m; the thickness of the substrate is 0.4 +/-0.01 mm.

In some embodiments, each RF MEMS switch is respectively connected with a controller module, and the on-off combination of each RF MEMS switch is automatically controlled by the controller module to adjust the transmitting frequency.

The invention has the beneficial effects that:

the multiband reconfigurable microstrip antenna is improved on the basis of the traditional truncated-angle antenna, and the RF MEMS switch is introduced to control the on-off of each truncated-angle patch and the main patch, so that the length of an average working current path is changed while the direction of a surface current path is changed, the frequency reconfiguration is realized in a K wave band and a Ka wave band, the universality and the integration degree of the reconfigurable microstrip antenna are greatly improved, and most frequency bands from 20GHz to 40GHz are basically covered.

Furthermore, an RF MEMS switch is introduced to control the on-off of the corner cut patch and the main patch, and the antenna has the advantages of low power consumption, high isolation, low insertion loss, low intermodulation component and low cost in the operation process.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

It will be appreciated by those skilled in the art that the objects and advantages that can be achieved with the present invention are not limited to the specific details set forth above, and that these and other objects that can be achieved with the present invention will be more clearly understood from the detailed description that follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:

fig. 1 is a perspective view of a multiband reconfigurable microstrip antenna according to an embodiment of the invention;

FIG. 2 is a front view of FIG. 1;

FIG. 3 is a top view of FIG. 1;

FIG. 4 is a schematic structural diagram of an RF MEMS switch in the multiband reconfigurable microstrip antenna according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a T-junction microstrip power divider in the multiband reconfigurable microstrip antenna according to an embodiment of the present invention;

fig. 6 is a schematic diagram of a transmission line model of a T-junction microstrip power divider in a multiband reconfigurable microstrip antenna according to an embodiment of the present invention.

Description of the drawings:

110: a metal ground; 120: a substrate; 130: a radiation patch;

131: a first type of corner cut patch; 132: a second type of corner cut patch; 133: a master patch;

134: an RF MEMS switch; 1341: the first switch is matched with the microstrip line; 1342: the second switch is matched with the microstrip line;

1343: a switch anchor area; 1344: a switch cantilever beam; 1345: pulling down the electrode;

140: a feed microstrip line.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the following embodiments and accompanying drawings. The exemplary embodiments and descriptions of the present invention are provided to explain the present invention, but not to limit the present invention.

It should be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and/or processing steps closely related to the scheme according to the present invention are shown in the drawings, and other details not so relevant to the present invention are omitted.

It should be emphasized that the term "comprises/comprising" when used herein, is taken to specify the presence of stated features, elements, steps or components, but does not preclude the presence or addition of one or more other features, elements, steps or components.

With the rapid development of economic society, the requirements of various industries on communication capacity and speed are higher and higher. Meanwhile, the rapid evolution of the mobile internet has also made miniaturization and integration of various communication devices to be an important current trend. This leads to the following challenges for antenna design: in a smaller and smaller design space, larger capacity and more reliable data communication are realized. In view of the above challenges, researchers in various countries around the world have made extensive and intensive research on the challenges, and have developed a trend of research and design of high frequency band, miniaturization, integration, and reconfigurability.

Radio Frequency Micro-electromechanical Systems (RF MEMS) technology-based Radio Frequency switches have the advantages of low power consumption, high isolation, low insertion loss, good high-Frequency performance, excellent linearity, and the like, and have an extremely important role in realizing Frequency, polarization, and directional diagram reconstruction of millimeter wave antennas. The invention is based on the truncated angle antenna, controls the on-off between each truncated angle patch and the main patch through the RF MEMS switch, changes the length of the average working current path while changing the direction of the surface current path, and realizes reconstruction at a plurality of wave band frequencies.

The invention particularly provides a multiband reconfigurable microstrip antenna, which adopts a non-uniform microstrip antenna large-truncated-angle structure based on an RF MEMS switch, and can realize multiband frequency reconfiguration facing a K waveband and a Ka waveband by utilizing on-off control of a few RF MEMS switches through control and regulation of surface current. As shown in fig. 1 to 3, the multiband reconfigurable microstrip antenna includes: metal ground 110, substrate 120, radiating patch 130 and feed microstrip line 140.

Wherein, the metal ground is used as a substrate for maintaining the common ground area voltage equipotential. Substrate 120 is disposed over metal ground 110 for carrying the antenna structure.

A radiation patch 130 disposed on the substrate 120, the radiation patch 130 having a rectangular shape, the radiation patch 130 being divided into two first type truncated corner patches 131 by two right angles at a first end in a length direction, and two second type truncated corner patches 132 by two right angles at a second end in the length direction, the remaining part of the radiation patch 130 being a main patch 133, the lengths of the oblique sides of the first type truncated corner patches 131 and the second type truncated corner patches 132 being different; each of the first truncated-angle-like patch 131 and the second truncated-angle-like patch 132 is connected to the main patch 133 through an RF MEMS (radio frequency micro electro mechanical system) switch, and the transmission frequency is reconstructed by on-off combination of the RF MEMS switches 134.

And a feeding microstrip line 140 connected to the main patch 133 for feeding.

The multiband reconfigurable microstrip antenna is realized based on the principle of the microstrip antenna, the radiation mechanism of the microstrip antenna is actually high-frequency electromagnetic leakage, and if a microwave circuit is not completely sealed by a conductor, the discontinuity in the circuit can generate electromagnetic radiation. For example, at the open end of a microstrip circuit, discontinuities such as abrupt changes in the structure size and bends may also generate electromagnetic radiation (leakage). When the frequency is low, the electrical size of these parts is small, and therefore the electromagnetic leakage is small; but as the frequency increases, the electrical size increases and the leakage becomes large. The antenna is made into a patch shape by enlarging the size, and the antenna works in a resonance state, so that the radiation is obviously enhanced, the radiation efficiency is greatly improved, and the antenna is an effective antenna.

In the present embodiment, the metal ground 110 may employ an aluminum sheet for maintaining a common ground region voltage or the like while reflecting electromagnetic waves. The substrate 120 is mainly used to carry the upper radiation patch 130, and the substrate 120 may be made of quartz glass and has a dielectric constant of 3.78.

The radiation patch 130 is a main component that generates electromagnetic wave radiation and performs multi-band frequency reconstruction. In the present embodiment, the radiation patch 130 is divided into a main patch 133 and 4 truncated corner patches, two first truncated corner patches 131 having the same size are divided along a first end of the main patch 133 in the length direction, and two second truncated corner patches 132 having the same size are divided along a second end of the main patch 133 in the length direction. The first truncated-angle patch 131 and the second truncated-angle patch 132 are respectively connected with the main patch 133 through an RF MEMS switch 134, and the length of an average working current path on the surface of the antenna, namely the effective size of the antenna, can be adjusted by controlling the connection and disconnection between each truncated-angle patch and the main patch 133, so that the frequency can be reconfigured. Furthermore, the lengths of the oblique sides of the first truncated-angle patch 131 and the second truncated-angle patch 132 are different, the lengths of the average working current paths distributed at the edges of the two truncated-angle patches are different, and the on-off of the switch makes the change of the surface current richer, so that more diversified frequency reconfigurability is finally formed, and the K waveband and the Ka waveband are basically covered.

In some embodiments, each RF MEMS switch 134 is connected to the controller module, and the on/off combination of each RF MEMS switch 134 is automatically controlled by the controller module to adjust the transmitting frequency.

The feed microstrip line 140 is a conductor strip, generally having a narrow width. In other embodiments, the power may also be fed in the form of coaxial probe power feeding or coupled power feeding according to the requirements in the practical application scenario.

In some embodiments, as shown in FIG. 4, the structure of each RF MEMS switch 134 includes: a first switch matching microstrip line 1341 and a second switch matching microstrip line 1342 respectively provided at both sides for providing impedance matching; a switch anchor region 1343 disposed on the first switch matching microstrip line 1341 or the second switch matching microstrip line 1342; a switch cantilever 1344 having a first side connected to the fixed switch anchor region 1343 and a second side suspended; the pull-down electrode 1345 is disposed at the bottom of the switch cantilever 1344, and adsorbs the switch cantilever 1344 and conducts the first switch matching microstrip line 1341 or the second switch matching microstrip line 1342 under the condition of loading direct current.

In this embodiment, a first switch matching microstrip line 1341 and a second switch matching microstrip line 1342 are respectively disposed on the main patch 133 and one of the truncated patches for providing impedance matching, and a switch anchor region 1343 is disposed on one side thereof for fixing the switch cantilever 1344. The switch cantilever 1344 moves up and down under the control of the pull-down electrode 1345, and adsorbs the switch cantilever 1344 under the condition that the pull-down electrode 1345 loads direct current, so that the adsorbed switch cantilever 1344 connects and conducts the first switch matching microstrip line 1341 and the second switch matching microstrip line 1342, and the corresponding main patch 133 and the truncated corner patch are also conducted. In other embodiments, other configurations of electrostatic, electromagnetic, electrothermal, or piezoelectric driven RF MEMS switches 134 may be provided, as desired for a particular application.

The electrostatic driving switch mainly controls the switch to be closed by means of electrostatic force between an upper polar plate and a lower polar plate of the switch, and has the advantages of being simple to manufacture and easy to integrate, and the defects of high driving voltage, easiness in environmental influence and poor stability. The electromagnetic drive type switch utilizes the magnetic field force generated by current to drive the movable component to realize the on-off of the switch, has the advantages of low driving voltage, high driving force, difficult environmental influence and breakdown, and has the defects of poor stability and difficult control. The electrothermal driving type switch realizes the switching action by utilizing the thermal expansion effect generated by electrifying materials, and the thermal driving has the advantages of simple manufacture, low driving voltage, large contact force, large switching action amplitude and the defects of long switching time and high power consumption. The piezoelectric driven switch realizes the on-off of the switch by utilizing the inverse piezoelectric effect generated by electrifying the piezoelectric material, and has the advantages of stronger stability, low driving voltage, low power consumption and complex process.

In some embodiments, the metal ground 110 is made of aluminum, which has good conductivity and can ensure bottom potential equalization. The substrate 120 is made of quartz glass, has good insulating property, and does not affect the main body structure of the microstrip antenna while bearing the main body structure of the microstrip antenna. The switch cantilever 1344 is made of the same material as the radiation patch 130, so that errors caused by material differences can be reduced, and the frequency reconstruction effect and stability can be ensured.

In some embodiments, an antenna prototype port is also provided on the primary patch 133 for collecting impedance information of the antenna structure during operation.

In some embodiments, the feeding microstrip line 140 is fed by a T-junction microstrip power divider. This embodiment may be used to construct a microstrip array antenna, and provides a 1 × 4T-junction microstrip power divider, where the T-junction power divider network is shown in fig. 5 and 6, where the access impedance at the load end D, F is Z₀Through a characteristic impedance ofAfter the impedance transformation of the transmission line with the electrical length of lambda/4, the input impedance Z of the BC terminal is seen at the junction point_in,BCCan be expressed as the calculation formula (1),

similarly, the input impedance of BE segment is also Z from point B_in,be＝2Z₀. Thus, the total input impedance, as seen from terminal A, is Z_in＝Z₀. A further advantage of using the T-type power splitting network is that the rf signal input at the a terminal has the same amplitude and phase after reaching the output terminal D, F. The T-shaped branch power distribution network is designed as shown in a structural schematic diagram, and can be seen to achieve better matching and power average distribution at the working frequency.

In some embodiments, the first truncated patch 131 and the second truncated patch 132 are isosceles right triangles. Further, the thickness of the radiation patch 130 is 1 ± 0.5 μm, and the width of the length of the radiation patch 130 is 6 ± 0.01 mm; the length of the radiation patch 130 is 4mm plus or minus 0.01mm, and the width of the length of the radiation patch 130 is 4mm plus or minus 0.01 mm; the length of the right-angle side of the first type of truncated patch 131 is 1.5 +/-0.01 mm; the lengths of the right-angled sides of the second type of corner-cut patches 132 are 0.8 +/-0.01 mm.

Based on the structure of the radiation patch 130 in this embodiment, in order to realize reconstruction of a plurality of frequencies in the K band and the Ka band, the size parameters of this embodiment are obtained by continuously adjusting the size parameters and the proportional relation of the structure through optimization simulation and simulation tests and theoretical and practical analysis, and a plurality of frequencies can be constructed in the K band and the Ka band to realize reconstruction.

In some embodiments, the length of the feed microstrip line 140 is 0.5 ± 0.01mm, and the width is 0.24 ± 0.01 mm; the RF MEMS switch 134 has a length of 0.25 + -0.01 mm and a width of 0.15 + -0.01 mm.

In some embodiments, the length of the metal ground and the substrate 120 is 5.5 ± 0.01mm, and the width is 6 ± 0.01 mm; the thickness of the metal ground is 1 +/-0.5 mu m; the thickness of the substrate 120 is 0.4 + -0.01 mm.

Embodiments are provided for a multi-band reconfigurable microstrip antenna, comprising: metal ground, substrate, radiation paster and feed microstrip line. The metal ground is used as a substrate for maintaining the common ground area voltage equipotential. The substrate is arranged above the metal ground for carrying the antenna structure. The radiation patch is arranged on the substrate and is rectangular, two right angles at the first end of the radiation patch in the length direction are divided into two first-class truncated corner patches, two right angles at the second end of the radiation patch in the length direction are divided into two second-class truncated corner patches, the rest part of the radiation patch is a main patch, and the lengths of the bevel edges of the first-class truncated corner patch and the second-class truncated corner patches are different; each first type of truncated corner patch and each second type of truncated corner patch are respectively connected with the main patch through an RF MEMS (radio frequency micro-electro-mechanical system) switch, and the emission frequency is reconstructed through the on-off combination of the RF MEMS switches. The feed microstrip line is connected with the main patch for feeding. The structure of each RF MEMS switch includes: the first switch matching microstrip line and the second switch matching microstrip line are respectively arranged on two sides and used for providing impedance matching; the switch anchor area is arranged on the first switch matching microstrip line or the second switch matching microstrip line; the first side of the switch cantilever beam is connected with the fixed switch anchor area, and the second side of the switch cantilever beam is suspended; and the pull-down electrode is arranged at the bottom of the switch cantilever beam, adsorbs the switch cantilever beam and conducts the first switch matching microstrip line or the second switch matching microstrip line under the condition of loading direct current.

Specifically, in this embodiment, the thickness of the radiation patch is 1 μm, and the width of the length of the radiation patch is 6 mm; the length of the radiation patch is 4mm, and the width of the length of the radiation patch is 4 mm; the length of the right-angle side of the first type of truncated patch is 1.5 mm; the length of the right-angle side of the second type of truncated patch is 0.8 mm. The length of the feed microstrip line is 0.5mm, and the width is 0.24 mm; the length of the RF MEMS switch is 0.25mm, the width of the RF MEMS switch is 0.15mm, the length of the metal ground and the length of the substrate are 5.5mm, and the width of the RF MEMS switch is 6 mm; the thickness of the metal ground is 1 μm; the thickness of the substrate is 0.4mm

The connection states of the first truncated corner patch type, the second truncated corner patch type and the main patch type in the present embodiment are labeled with "0" and "1", where "0" denotes an open circuit and "1" denotes a closed circuit. And marking the on-off states of the RF MEMS switches corresponding to the two first type of corner cutting patches and the two second type of corner cutting patches by adopting 4-bit codes, marking the RF MEMS switches corresponding to the first type of corner cutting patches on the upper left corner and the upper right corner respectively by the first two bits, and marking the RF MEMS switches corresponding to the second type of corner cutting patches on the lower left corner and the lower right corner respectively by the second two bits. The multiband reconfigurable microstrip antenna in the embodiment can work in 11 modes and obtain 11 states. By changing the disconnection and connection between the main patch and the four truncated corner patches, the radiation of up to 13 frequency bands can be realized in the frequency band of 20GHz to 40GHz, and 3 broadband with the bandwidth of more than 2.5GHz is included. Specifically, the on-off state of each RF MEMS switch and the frequency corresponding relationship of the signal transmitted by the microstrip antenna in the corresponding state are shown in table 1 below:

TABLE 1 comparison table of on-off state and radiation frequency band of each RF MEMS switch

Analysis of several typical switch states follows, and it can be seen from the antenna structure that the length of the hypotenuse of the upper two truncated corner patches is greater than the length of the hypotenuse of the lower two truncated corner patches. Therefore, the lengths of the average working current paths distributed at the edges of the two truncated corner patches are different, and the on-off of the switch is added, so that the change of the surface current is richer, and finally, more diversified frequency reconfigurability is formed and the K wave band and the Ka wave band are basically covered. For the antenna in the 0100 state, radiation of 25.96GHz is generated at a gap between the first truncated-angle patch at the upper right corner and the main patch; for the antenna in the 0000 state, the radiation of 32.42GHz and 35.07GHz is generated at the gap between the second truncated-angle patch and the main patch at the lower left corner; for the antenna in the 0001 state, 34.89GHz radiation is generated at the gap between the second truncated-angle patch in the lower right corner and the main patch. As can be seen, with the antenna structure of the present embodiment, each frequency can be effectively reconfigured by controlling the on-off state of each RF MEMS switch.

In summary, the multiband reconfigurable microstrip antenna is improved on the basis of the traditional truncated-angle antenna, and the RF MEMS switch is introduced to control the on-off of each truncated-angle patch and the main patch, so that the length of an average working current path is changed while the direction of a surface current path is changed, thereby realizing frequency reconfiguration in a K band and a Ka band, greatly improving the universality and the integration degree of the reconfigurable microstrip antenna, and basically covering most frequency bands from 20GHz to 40 GHz.

Furthermore, an RF MEMS switch is introduced to control the on-off of the corner cut patch and the main patch, and the antenna has the advantages of low power consumption, high isolation, low insertion loss, low intermodulation component and low cost in the operation process.

Those of ordinary skill in the art will appreciate that the various illustrative components, systems, and methods described in connection with the embodiments disclosed herein may be implemented as hardware, software, or combinations of both. Whether this is done in hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention. When implemented in hardware, it may be, for example, an electronic circuit, an Application Specific Integrated Circuit (ASIC), suitable firmware, plug-in, function card, or the like. When implemented in software, the elements of the invention are the programs or code segments used to perform the required tasks. The program or code segments may be stored in a machine-readable medium or transmitted by a data signal carried in a carrier wave over a transmission medium or a communication link.

Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments and/or in combination with or instead of the features of the other embodiments in the present invention.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes may be made to the embodiment of the present invention by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.