CN104269613A - High-isolation MIMO tri-band antenna - Google Patents

Abstract

The invention relates to the field of antennas, in particular to a high-isolation MIMO tri-band antenna. Using two radiating element antenna technology placed symmetrically in space and loaded with short-circuit wiring, a high-isolation MIMO inverted-F antenna that can be used in the E-band of the TD-LTE system, the 5.2GHz frequency band of the WLAN system and the 3.5GHz frequency band of the WIMAX system is proposed. , the central operating frequencies of the antenna are 2.35GHz, 3.5GHz and 5.2GHz respectively, and the isolation of the antenna at the above-mentioned central operating frequencies are -16.05dB, -8.25dB and -19.41dB respectively, realizing the inverted F antenna in the MIMO system The high isolation between units works, and at the same time, the antenna can not only transmit signals to different spatial orientations in the above-mentioned frequency bands, but also receive signals from different spatial orientations, and has a good MIMO function.

Description

A high-isolation MIMO tri-band antenna

technical field

The invention relates to the field of antennas, in particular to a high-isolation MIMO tri-band antenna. the

Background technique

With the rapid development of radio technology, wireless communication devices have been widely used in people's daily life. Among the various antenna forms of built-in antennas in wireless communication equipment, the inverted-F antenna is widely used in wireless communication fields such as WLAN, WIMAX, and TD-LTE systems because of its small size, simple structure, easy matching, and low antenna manufacturing cost. the

In recent years, Wireless Local Area Networks (WLAN) and Worldwide Interoperability for Microwave Access (WIMAX) have been widely promoted and applied. WLAN is based on the IEEE802.11 standard, which can be used to transmit data, audio and video signals, and the like. WIMAX is based on the IEEE802.16 standard, which can realize high-speed Internet-oriented data transmission with a maximum transmission distance of 50 kilometers. At present, the main working frequency bands of WLAN are 2.45GHz frequency band (2.4-2.484GHz), 5.2GHz frequency band (5.15-5.35GHz) and 5.8GHz frequency band (5.725-5.825GHz), and WIMAX mainly works in the 2.5GHz frequency band (2.5-2.69GHZ) , 3.5GHz frequency band (3.4-3.69GHZ) and 5.5GHz frequency band (5.25-5.85GHZ). the

TD-LTE (Time Division Long Term Evolution) is a global standard based on OFDMA technology and formulated by 3GPP. TD-LTE technology is based on TD-SCDMA technology and can provide wireless multimedia communication services. It has become one of the fourth-generation mobile communication technologies. The E frequency band of TD-LTE is 2.32-2.37GHz. the

MIMO stands for multiple-input multiple-output technology, which arranges multiple antenna units according to certain rules at the signal transmitting end and receiving end of the system, so as to realize the simultaneous transmission and reception of signals in multiple spatial orientations, and improve the capacity and spectrum utilization of the communication system The rate and the reliability of the channel can alleviate the problem of insufficient spectrum resources to a certain extent. the

For the trend of miniaturization and multi-function of wireless communication equipment at this stage, the terminal antenna suitable for wireless communication equipment also puts forward the requirements of miniaturization, multi-band, high isolation, and the ability to transmit and receive signals from different directions in space. , but the current common inverted-F antenna has a single operating frequency, and the isolation between the inverted-F antenna elements placed in the MIMO system is low and the mutual interference is serious. Therefore, how to improve the isolation between the inverted-F antenna units in the MIMO system, increase the working frequency band of the inverted-F antenna to make it suitable for more miniaturized and multi-functional communication devices, and further promote the application of the inverted-F antenna key issues that need to be addressed at this stage. the

Contents of the invention

The purpose of the present invention is to provide a MIMO tri-band antenna with better isolation, which is specifically realized by the following technical solutions:

A high-isolation MIMO tri-band antenna, including two radiating elements and a dielectric substrate, the two sides of the dielectric substrate respectively have a ground plane and a non-ground plane, and the ground plane on one side corresponds to the non-ground plane on the other side , the two radiating units are attached to the non-ground plane on one side of the dielectric substrate and connected to the ground plane in a short circuit.

The high-isolation MIMO tri-band antenna is further designed in that the radiating unit is an inverted-F antenna with a first radiator, a second radiator and a third radiator, and the first radiator and the third radiator The radiators are parallel to each other and one end of the two radiators is vertically connected to one end and the middle of the second radiator to form an F shape. The first radiator and the second radiator are respectively connected to the ground plane through the first short-circuit connection and the second short-circuit connection. The other end of the three radiators is the feed source of the inverted-F antenna. the

The high-isolation MIMO tri-band antenna is further designed in that the dielectric substrate is rectangular and made of FR4 material, and the non-ground plane is a rectangle whose width is less than the width of the dielectric substrate and whose length is half the length of the dielectric substrate. The parts other than the non-ground plane are pasted with a copper plane to form a ground plane. the

The high-isolation MIMO tri-band antenna is further designed in that two openings are provided at a time along the midline in the width direction of the dielectric substrate on the same side of the dielectric substrate as the feed source of the inverted-F antenna. the

The high-isolation MIMO tri-band antenna is further designed in that the thickness of the dielectric substrate is 1.5mm, the length is 53.0mm, and the width is 11.0mm, and the two openings are square, and the depth is the same as that of the dielectric substrate. The same substrate is 0.2mm, and its side length is 1.5mm; the thickness of the copper surface of the ground plane is 0.036mm, the width of the inverted F antenna and the first short-circuit connection 4 are both 0.6mm, and the thickness is 0.036mm, and the second short-circuit connection 5 has a width of 0.9mm and a thickness of 0.036mm; the inverted F antenna, the first short-circuit connection and the second short-circuit connection are all made of copper material. the

The beneficial effects of the present invention are:

The present invention adopts two radiating element antenna technologies that are placed symmetrically in space and loaded with short-circuit wiring, and proposes a high-isolation MIMO inverter that can be used in the E frequency band of the TD-LTE system, the 5.2GHz frequency band of the WLAN system, and the 3.5GHz frequency band of the WIMAX system. F antenna, the working frequency band of the antenna is 2.32-2.38GHz, 3.43-3.55GHz and 5.13-5.25GHz, the central working frequency is 2.35GHz, 3.5GHz and 5.2GHz respectively, and the isolation degree of the antenna at the above-mentioned central working frequencies is respectively -16.05dB, -8.25dB and -19.41dB, realize the high isolation between the inverted F antenna elements in the MIMO system, and at the same time, the antenna can transmit to different spatial directions in the 2.35GHz, 3.5GHz and 5.2GHz frequency bands Signals can also receive signals from different spatial orientations, and have better MIMO functions. The maximum gain of the antenna is 2.63dBi, realizing the high-gain working characteristic of the antenna.

Description of drawings

Fig. 1 is a schematic side view of the structure of the present invention. the

Fig. 2 is a schematic diagram of the upper surface of the present invention. the

Fig. 3 is a schematic diagram of the lower surface of the present invention. the

FIG. 4 is a schematic diagram of the parameters of the return loss S(1,1) and the return loss S(2,2) in the case of using the feed source 8 as the port in the present invention. the

FIG. 5 is a schematic diagram of parameters of the isolation S(1, 2) in the case of feeding with the feed source 8 as the port according to the present invention. the

Among them, 1-radiating unit, 2-dielectric substrate, 3-ground plane, 4-first short-circuit connection, 5-second short-circuit connection, 6-first opening, 7-second opening, 8-feed source.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments. the

1, 2 and 3, the high-isolation MIMO tri-band antenna includes two radiating elements 1 and a dielectric substrate 2, the two sides of the dielectric substrate 2 have a ground plane 21 and a non-ground plane 22, and one side The ground plane on the other side corresponds to the non-ground plane on the other side, and the two radiating units are attached to the non-ground plane on one side of the dielectric substrate and short-circuited with the ground plane, so that the two radiating units are staggered and arranged on both sides of the dielectric substrate. on one side. the

The radiation unit 1 is an inverted F antenna, which is divided into a linear first radiator 11, a second radiator 12 and a third radiator 13, the first radiator 11 and the third radiator 13 are parallel to each other and The first radiator 11 and the second radiator 12 are respectively connected to the ground plane 21 through the first short-circuit connection 4 and the second short-circuit connection 5, and the third The other end of the radiator 13 is the feed source 8 of the inverted-F antenna. the

The dielectric substrate 2 is rectangular and made of FR4 material. The non-ground plane 22 is a rectangle whose width is smaller than the width of the dielectric substrate and whose length is half the length of the dielectric substrate. On the same side of the dielectric substrate 2 as the feed source 8 of the inverted-F antenna, two openings are provided at a time along the midline in the width direction of the dielectric substrate, namely the first opening 6 and the second opening 7 . the

The specific dimensions and materials of each part of the present invention are as follows. The thickness of the dielectric substrate is 1.5mm, the length is 53.0mm, and the width is 11.0mm. Both openings are square, and the side length of the two is 0.2mm. The thickness of the substrate is the same as 1.5mm; the thickness of the copper surface of the ground plane is 0.036mm; The thickness is 0.036mm; the inverted F antenna, the first short-circuit connection and the second short-circuit connection are all made of copper material. the

In order to have a further understanding of the various performances of the present invention, the corresponding test data diagrams are drawn through specific tests. the

Referring to Figure 4, the simulation curve diagram of the return loss parameters in the case of the antenna with the feed source 8 as the port is given. From the figure, it can be seen that the working frequency bands of the radiation unit 1 are 2.32-2.38GHz and 3.43-3.55GHz And 5.13-5.25GHz, the center operating frequencies are 2.35GHz, 3.5GHz and 5.2GHz respectively. the

Referring to Figure 5, a simulation curve diagram of the isolation parameter of the antenna with the feed source 8 as the port is given. From the figure, we can see the isolation of the antenna at 2.35GHz, 3.5GHz and 5.2GHz as the center operating frequency The degrees are -16.05dB, -8.25dB and -19.41dB respectively, realizing a working antenna with high antenna isolation, and the overall performance of the antenna meets the index requirements of TD-LTE, WIMAX and WLAN systems. the

The maximum gain of the antenna of the present invention can reach 2.63dBi under the condition that the feed source 8 is used as the port feed, and the high-gain working characteristic of the antenna is realized. the

The design parameters of this patent are selected on the basis of certain theoretical analysis, and the experimental results show that the performance of the antenna is good. The experimental results of this embodiment show that the antenna's central operating frequency is 2.35GHz, and the operating frequency band is 2.32GHz to 2.38GHz, and the bandwidth is 60MHz, which completely covers the requirements of the 2.32-2.37GHz frequency band required by the E frequency band of the TD-LTE system. The return loss is -15.43dB, The return loss is -20.12dB; the working frequency band is 3.43GHz to 3.55GHz at the center operating frequency of 3.5GHz, and the bandwidth is 120MHz. The return loss is -15.39dB, The return loss is -15.53dB; the working frequency band is 5.13GHz to 5.25GHz at the center operating frequency of 5.2GHz, and the bandwidth is 120MHz. The return loss is -15.66dB, The return loss is -17.16dB, the antenna can receive signals from multiple directions at the same time in the 2.35GHz frequency band, 3.5GHz frequency band and 5.2GHz frequency band, and can also transmit signals to multiple directions at the same time, which can be widely used with multiple wireless communication terminal.

the

Claims (5)

1. A high-isolation MIMO tri-band antenna is characterized in that it comprises two radiating elements and a dielectric substrate, the two sides of the dielectric substrate have a ground plane and a non-ground plane respectively, and the ground plane on one side is connected to the other side Corresponding to the non-ground plane of the dielectric substrate, the two radiation units are attached to the non-ground plane on one side of the dielectric substrate and short-circuited to the ground plane. 2. The high-isolation MIMO tri-band antenna according to claim 1, wherein the radiation unit is an inverted-F antenna with a first radiator, a second radiator and a third radiator, and the first radiator The radiator and the third radiator are parallel to each other, and one end of the two is vertically connected to one end and the middle of the second radiator respectively to form an F shape. The ground plane is connected, and the other end of the third radiator is the feed source of the inverted-F antenna. 3. The high-isolation MIMO tri-band antenna according to claim 2, wherein the dielectric substrate is rectangular and made of FR4 material, and the non-ground plane has a width less than the width of the dielectric substrate and a length equal to that of the dielectric substrate Half the length of the rectangle, the part other than the non-ground plane is bonded with a copper plane to form a ground plane. 4. high isolation degree MIMO tri-band antenna according to claim 2, is characterized in that, described dielectric substrate and the feed source identical side edge of the medium substrate of the width direction of dielectric substrate are once provided with two openings. hole. 5. The high-isolation MIMO tri-band antenna according to claim 4, wherein the thickness of the dielectric substrate is 1.5mm, the length is 53.0mm, and the width is 11.0mm, and the two openings are square , the side length of both is 0.2mm, and its depth is the same as that of the dielectric substrate, which is 1.5mm; the thickness of the copper surface of the ground plane is 0.036mm, and the width of the inverted F antenna and the first short-circuit connection 4 is 0.6mm, and the thickness is 0.036mm. mm, the width of the second short-circuit wire 5 is 0.9 mm, and the thickness is 0.036 mm; the inverted F antenna, the first short-circuit wire, and the second short-circuit wire are all made of copper materials.