CN209516001U - A kind of differential feed size three-frequency planar antenna - Google Patents

Abstract

The utility model discloses a kind of differential feed size three-frequency planar antennas, including reflecting plate, support construction, medium substrate, the first feeder line, the second feeder line and antenna radiation unit；Reflecting plate is pedestal；Medium substrate is fixed on reflecting plate by support construction；Support construction includes M root support column, and support column is insulating materials；Antenna radiation unit is etched on medium substrate, including a low-frequency vibrator, the first intermediate frequency oscillator, the second intermediate frequency oscillator, the first high frequency oscillator, the second high frequency oscillator, coplanar microstrip line and feed microstrip line structure.The utility model uses differential feed structure combination planar structure, can realize that three frequencies work convenient for combining with differential radio frequency front end, have the advantages that high gain and antenna pattern are stable.

Description

A Differentially Feed Tri-Band Planar Antenna

technical field

The utility model relates to the field of mobile communication, in particular to a differential feed tri-frequency planar antenna.

Background technique

With the rapid development of communication systems in recent decades, people's requirements for communication systems continue to increase. Antennas, as the core components of modern communication systems, also put forward higher and higher requirements. Most traditional antennas use a single-port feed mode. In order to solve the integration of the single-port antenna and the RF front-end, a balun (balun) is usually used to convert the differential signal into a single-port signal and then feed it to the single-port antenna. However, single-port antennas limit the use and popularity of integrated RF front-ends using differential ports. The differential antenna uses two feed ports, which can directly connect the two ports of the antenna to the RF front end of the differential port, thereby improving the integration of the system, reducing the loss of the signal at the input port, and improving the efficiency of the antenna. At the same time, the differential The antenna adopts a completely symmetrical structure with extremely low cross-polarization. Therefore, the research on the differential antenna has very important practical significance and good application prospects.

With the development of modern mobile communication, the communication frequency band is constantly increasing, usually more antennas need to be deployed to meet the increasing communication needs, and the tri-band antenna can meet the communication system requirements of multiple standards with one antenna, which can It has the advantages of saving production cost, reducing the area occupied by the antenna, and reducing the complexity of the communication system. In the field of wireless network access, WiMAX and Wi-Fi vertical switching technologies have been developed and utilized at this stage. If the Wi-Fi system and the WiMAX system can work simultaneously, it can realize long-distance transmission, high-speed broadband access, and has flexibility and mobility. Therefore, WLAN/WiMAX tri-band antenna, as one of the key components of WLAN system, has theoretical significance and practical value in its research.

There are two common implementation methods of differentially fed tri-band antennas, which are ultra-wideband filter antennas and multi-element antennas. Ultra-wideband filter antennas have the advantages of wide bandwidth and easy bandwidth control, but the structural design of ultra-wideband filter antennas is relatively complicated, and has problems such as low gain and unstable pattern; multi-element antennas are generally direct combinations of multiple independent oscillators , it is necessary to set an independent feed port for each frequency band, which increases the complexity of the system, and most of the dipole antennas are three-dimensional structures, which occupy a large radiation area and are not easy to be deployed on a large scale in actual situations.

Utility model content

The purpose of the utility model is to overcome the deficiencies of the prior art and provide a differentially fed three-frequency planar antenna. The antenna adopts a planar structure, has the characteristics of high radiation gain and stable pattern, and can cover 2.45-GHz, 3.5-GHz and 5-GHz frequency bands.

The purpose of this utility model can be realized through the following technical solutions:

A differentially fed three-frequency planar antenna, comprising a reflector, a support structure, a dielectric substrate, a first feeder, a second feeder, and an antenna radiation unit;

The reflector is the base and adopts a metal plate;

The dielectric substrate is fixed on the reflection plate through a supporting structure, and the fixing surface of the supporting structure is the back side of the dielectric substrate;

The support structure includes M support columns, the support columns are insulating materials, M≥4;

The antenna radiating unit is etched on the dielectric substrate, including a low-frequency oscillator, a first intermediate-frequency oscillator, a second intermediate-frequency oscillator, a first high-frequency oscillator, a second high-frequency oscillator, a coplanar microstrip line, and a microstrip line feed structure ; The low-frequency oscillator is symmetrical about the center of the antenna radiating unit, and the end is extended in a T-shaped structure; the first intermediate-frequency oscillator and the second intermediate-frequency oscillator are respectively connected to the low-frequency oscillator through a coplanar microstrip line, and the first intermediate-frequency oscillator and the second intermediate-frequency oscillator are about the low-frequency The long side of the vibrator is symmetrical; the first high frequency vibrator is connected to the first intermediate frequency vibrator through a coplanar microstrip line, the second high frequency vibrator is connected to the second intermediate frequency vibrator through a coplanar microstrip line, and the first high frequency vibrator is connected to the second high frequency vibrator. The high-frequency vibrator is symmetrical about the long side of the low-frequency vibrator; the microstrip line feed structure connects the two long sides of the low-frequency vibrator, and is not coplanar with the low-frequency vibrator, the intermediate-frequency vibrator and the high-frequency vibrator.

The first feeder is connected to the dielectric substrate through the reflector; the second feeder is connected to the dielectric substrate through the reflector; the inner core of the first feeder is welded to one end of the microstrip feed structure through a non-metallized via hole, and the second feeder is connected to the dielectric substrate through a non-metallized via hole. The inner core of the feeder is welded to one end of the microstrip feeder structure through a non-metallized via hole, and the outer core of the first feeder and the outer core of the second feeder are respectively welded to the two long sides of the low-frequency oscillator.

Specifically, the low frequency oscillator, intermediate frequency oscillator and high frequency oscillator are all etched on the back of the dielectric substrate; the microstrip feed structure is etched on the front of the dielectric substrate; the coplanar microstrip line is etched on the front of the dielectric substrate .

Further, the antenna radiation unit is an axisymmetric structure, and the axis of symmetry transversely passes through the center of the antenna radiation unit.

Further, the two intermediate-frequency oscillators are connected in parallel with the low-frequency oscillator through a coplanar microstrip line, and one end of the intermediate-frequency oscillator is bent in the opposite direction of the low-frequency oscillator, which can be used to cover the low-frequency 2.45-GHz frequency band and the intermediate-frequency 3.5-GHz frequency band.

Furthermore, the two high-frequency oscillators are connected in parallel with the intermediate-frequency oscillator through a coplanar microstrip line, and one end of the high-frequency oscillator is bent toward the direction of the low-frequency oscillator, which can be used to cover the low-frequency 2.45-GHz frequency band, the intermediate frequency 3.5-GHz frequency band, and the high-frequency 5-GHz frequency band. -GHz band.

Further, the feeding structure of the microstrip line is a metal stub, which is symmetrical with respect to the antenna radiation unit and parallel to the long side of the low-frequency oscillator.

Preferably, the characteristic impedance of the microstrip feed structure is 50Ω.

Compared with the prior art, the utility model has the following beneficial effects:

1. The differential feed technology is adopted in the utility model, which avoids the loss of the radio frequency front end caused by the use of the balun, and improves the efficiency of the antenna. At the same time, it adopts a planar structure and a collective oscillator, which can reduce the feeding port, reduce the radiation area, and improve the integration of the radio frequency front end. It has the advantages of simple structure, easy manufacture and large-scale arrangement in actual occasions.

2. The utility model can cover three frequency bands of wireless local area network 2.45-GHz, 5-GHz frequency band and WiMAX3.5-GHz frequency band, and the gain can reach more than 8.0dBi in the 2.40-5.51GHz frequency band, and the gain in the 3.40-3.60GHz frequency band It can achieve more than 8.5dBi, and the gain can reach more than 8.0dBi in the 5.14-6.05 frequency band. It has the advantages of stable pattern and extremely low cross polarization.

Description of drawings

Fig. 1 is a three-dimensional structural schematic diagram of a differentially fed tri-band planar antenna described in the present invention.

Fig. 2 is a cross-sectional view of a differentially fed tri-band planar antenna described in the present invention.

Fig. 3 is a front view of a differentially fed tri-band planar antenna described in the present invention.

Fig. 4 is a schematic diagram of the impedance bandwidth of a differentially fed tri-band planar antenna described in the present invention.

Fig. 5 is a gain schematic diagram of a differentially fed tri-band planar antenna described in the present invention.

Fig. 6 (a) and Fig. 6 (b) are a kind of differentially fed tri-band planar antenna described in the utility model at 2.45GHz radiation front face pattern and left face pattern.

Fig. 7 (a) and Fig. 7 (b) are a kind of differentially fed tri-band planar antenna described in the utility model at 3.5GHz radiation front face pattern and left face pattern.

Fig. 8 (a) and Fig. 8 (b) are a kind of differentially fed tri-band planar antenna described in the utility model at 5.2GHz radiation front face pattern and left face pattern.

Fig. 9 (a) and Fig. 9 (b) are a kind of differentially fed tri-band planar antenna described in the utility model at 5.8GHz radiation front face pattern and left face pattern.

In the figure, 1-radiating unit, 2-reflector, 3A-first feeder, 3B-second feeder, 4-support structure, 5A-first high-frequency vibrator, 5B-second high-frequency vibrator, 6A-first Intermediate frequency oscillator, 6B-second intermediate frequency oscillator, 7-low frequency oscillator, 8-microstrip line feed structure, 9-coplanar microstrip line, 10A-first non-metallized via, 10B-second non-metallized via Holes, 11 - Dielectric substrate.

Detailed ways

The utility model will be further described in detail below in conjunction with the embodiments and accompanying drawings, but the implementation of the utility model is not limited thereto.

Example

As shown in Figure 1-3, it is a structural diagram of a differentially fed tri-frequency planar antenna, which includes a reflector 2, a support structure 4, a first feeder 3A, a second feeder 3B, a dielectric substrate 11 and an antenna radiation unit 1.

The reflector is the base and adopts a metal plate;

The dielectric substrate is fixed on the reflection plate through a supporting structure, and the fixing surface of the supporting structure is the back side of the dielectric substrate;

The support structure includes M support columns, the support columns are insulating materials, M≥4;

In this embodiment, the reflection plate 3 is made of aluminum plate; the dielectric substrate 11 is made of high-frequency plate Rogers4350B, with a thickness of 0.76 mm and a relative dielectric constant of 3.48; the supporting columns in the supporting structure 4 are made of plastic.

The dielectric substrate is fixed on the reflector through the support structure, and the antenna radiation unit is etched on the dielectric substrate; the first feeder and the second feeder respectively feed differential signals with equal amplitude and 180 degrees of phase difference; both the first feeder and the second feeder use Soft coaxial, the inner core of the first feeder is welded to one end of the microstrip feed structure 8 through the non-metallized via hole 10A, and the second feeder inner core is connected to the other end of the microstrip feed structure through the non-metallized via hole 10B Welding: the outer cores of the first feeder and the second feeder are respectively welded to the two long sides of the low-frequency vibrator.

The antenna radiating unit is etched on the dielectric substrate, including a low frequency oscillator 7, a first intermediate frequency oscillator 6A, a second intermediate frequency oscillator 6B, a first high frequency oscillator 5A, a second high frequency oscillator 5B, a coplanar microstrip line 9 and Microstrip line feed structure 8; the low-frequency vibrator is symmetrical about the center of the antenna radiation unit, and the end is extended to form a T-shaped structure, and the extension end is the bottom end of the low-frequency vibrator; the first intermediate frequency vibrator and the second intermediate frequency vibrator respectively pass through the coplanar microstrip line Connected to the low-frequency oscillator, the first intermediate-frequency oscillator and the second intermediate-frequency oscillator are symmetrical about the long side of the low-frequency oscillator; the first high-frequency oscillator is connected to the first intermediate-frequency oscillator through a coplanar microstrip line, and the second high-frequency oscillator is passed through a coplanar microstrip line Connected to the second intermediate frequency oscillator, the first high frequency oscillator and the second high frequency oscillator are symmetrical about the long side of the low frequency oscillator; the microstrip line feed structure connects the two long sides of the low frequency oscillator, and is not connected to the low frequency oscillator, the intermediate frequency oscillator and the high frequency oscillator. The oscillators are coplanar.

The antenna radiation unit is an axisymmetric structure, and the axis of symmetry transversely passes through the center of the antenna radiation unit. The bottom ends of the low-frequency vibrator are opposite, symmetrical to the center of the antenna radiation unit, and the low-frequency vibrator is etched on the back of the dielectric substrate;

The two intermediate frequency oscillators are connected in parallel with the low frequency oscillator through a coplanar microstrip line, one end of the two intermediate frequency oscillators is bent in the opposite direction of the low frequency oscillator, and the non-bending ends are the bottom ends of the first intermediate frequency oscillator and the second intermediate frequency oscillator. The bottom end of the first intermediate frequency oscillator is connected to the bottom end of the low frequency oscillator through a coplanar microstrip line, the bottom end of the second intermediate frequency oscillator is connected to the bottom end of the low frequency oscillator through a coplanar microstrip line, the first intermediate frequency oscillator and the second intermediate frequency The vibrator is symmetrical to the center of the antenna radiation unit, and the first intermediate frequency vibrator and the second intermediate frequency vibrator are etched on the back of the dielectric substrate.

The two high-frequency oscillators are connected in parallel with the intermediate-frequency oscillator through a coplanar microstrip line. One end of the two high-frequency oscillators is bent toward the direction of the low-frequency oscillator, and the non-bent end is the bottom end of the first high-frequency oscillator and the second high-frequency oscillator. . The bottom end of the first high frequency oscillator is connected to the bottom end of the second intermediate frequency oscillator through a coplanar microstrip line, and the bottom end of the second high frequency oscillator is connected to the bottom end of the second intermediate frequency oscillator through a coplanar microstrip line. The first high-frequency vibrator and the second high-frequency vibrator are symmetrical to the center of the antenna radiation unit, and the first high-frequency vibrator and the second high-frequency vibrator are etched on the back of the dielectric substrate.

The microstrip feed structure is a metal stub, and the microstrip feed structure is symmetrical about the symmetry axis of the antenna radiation unit, parallel to the long side of the low-frequency oscillator, and the microstrip feed structure is etched on the front side of the dielectric substrate. In this embodiment, the characteristic impedance of the microstrip feed structure is 50Ω.

As shown in Figure 4, it is the impedance bandwidth of the present embodiment, can draw a conclusion from the figure, the differential feed tri-frequency planar antenna of the present utility model has 2.40-2.51GHz, 3.40-3.60GHz, the impedance bandwidth of 5.14-6.05GHz , the return loss basically reaches -15dB, which can cover the 2.40-2.48GHz frequency band, 5.2-5.8GHz frequency band of WLAN and the 3.4-3.6GHz frequency band of WiMAX. The gain in the frequency band reaches more than 8.0dBi, the gain in the 3.4-3.6GHz frequency band reaches more than 8.5dBi, and the gain in the 5.2-5.8GHz frequency band reaches more than 8.0dBi.

As shown in Figure 6(a) and Figure 6(b), taking Figure 2 as the left view, Figure 6(a) is the gain front direction diagram of this example at the center frequency point of the 2.4GHz frequency band, and Figure 6(b) is This example shows the left-view pattern of the gain at the center frequency point of the 2.4GHz frequency band. It can be seen from the figure that the differentially fed tri-band planar antenna has a stable radiation direction gain pattern, and the front-to-back ratio is greater than 10dB. The antenna is suitable for WLAN systems.

As shown in Figure 7(a) and Figure 7(b), taking Figure 2 as the left view, Figure 7(a) is the gain front direction diagram of this example at the center frequency point of the 3.5GHz frequency band, and Figure 7(b) is This example shows the left-view pattern of the gain at the center frequency point of the 3.5GHz frequency band. It can be seen from the figure that the differentially fed tri-band planar antenna has a stable radiation direction gain pattern, and the front-to-back ratio is greater than 15dB. The antenna is suitable for WiMAX systems.

As shown in Figure 8(a) and Figure 8(b), taking Figure 2 as the left view, Figure 8(a) is the gain front direction diagram of this example at the center frequency point of the 5.2GHz frequency band, and Figure 8(b) is This example shows the left-view pattern of the gain at the center frequency point of the 5.2GHz frequency band. It can be seen from the figure that the differentially fed tri-band planar antenna has a stable radiation direction gain pattern, and the front-to-back ratio is greater than 15dB. The antenna is suitable for WLAN systems.

As shown in Figure 9(a) and Figure 9(b), taking Figure 2 as the left view, Figure 9(a) is the gain front direction diagram of this example at the center frequency point of the 5.8GHz frequency band, and Figure 9(b) is This example shows the left-view pattern of the gain at the center frequency point of the 5.8GHz frequency band. It can be seen from the figure that the differentially fed tri-band planar antenna has a stable radiation direction gain pattern, and the front-to-back ratio is greater than 15dB. The antenna is suitable for WLAN systems.

In this embodiment, only one radiating unit can cover three frequency bands to obtain an impedance bandwidth of 15dB. It has a simple planar structure and is easy to manufacture; and this embodiment is fed by differential, which is beneficial to the integration with the radio frequency front end; Large, the impedance bandwidth can cover the 2.40-2.48GHz frequency band of WLAN, the 3.4-3.6GHz frequency band of WiMAX and the 5.2-5.8GHz frequency band, the antenna gain is high, and the radiation pattern is stable at the same time.

The above-mentioned embodiment is a preferred implementation mode of the present utility model, but the implementation mode of the present utility model is not limited by the above-mentioned embodiment, and any other changes, modifications and substitutions made without departing from the spirit and principle of the present utility model , combination, and simplification, all should be equivalent replacement methods, and are all included in the protection scope of the present utility model.

Claims (6)

1. a kind of differential feed size three-frequency planar antenna, which is characterized in that including reflecting plate, support construction, medium substrate, the first feedback Line, the second feeder line and antenna radiation unit；

The reflecting plate is pedestal, using metal plate；

The medium substrate is fixed on reflecting plate by support construction, and support construction stationary plane is the back side of medium substrate；

The support construction includes M root support column, and support column is insulating materials, M >=4；

The antenna radiation unit is etched on medium substrate, including a low-frequency vibrator, the first intermediate frequency oscillator, frequency vibration in second Son, the first high frequency oscillator, the second high frequency oscillator, coplanar microstrip line and feed microstrip line structure；Low-frequency vibrator is about antenna spoke The central symmetry of unit is penetrated, extend T-shaped structure for end；First intermediate frequency oscillator and the second intermediate frequency oscillator pass through coplanar micro-strip respectively Line is connect with low-frequency vibrator, and the first intermediate frequency oscillator is symmetrical about low-frequency vibrator long side with the second intermediate frequency oscillator；First high frequency oscillator It is connect by coplanar microstrip line with the first intermediate frequency oscillator, the second high frequency oscillator is connected by coplanar microstrip line and the second intermediate frequency oscillator It connects, the first high frequency oscillator is symmetrical about low-frequency vibrator long side with the second high frequency oscillator；Feed microstrip line structure connects low-frequency vibrator Two long sides, and it is not coplanar with low-frequency vibrator, intermediate frequency oscillator and high frequency oscillator；

First feeder line passes through reflecting plate and connects medium substrate；Second feeder line passes through reflecting plate and connects medium substrate；The One feeder line inner core is welded by one end of non-metallic via hole and feed microstrip line structure, and the inner core of the second feeder line passes through nonmetallic The one end for changing via hole and feed microstrip line structure is welded, the outer core of the outer core of the first feeder line and the second feeder line respectively with low-frequency vibrator Two long sides welded；

The low-frequency vibrator, intermediate frequency oscillator and high frequency oscillator are etched in the back side of medium substrate；The feed microstrip line structure It is etched in the front of medium substrate；The coplanar microstrip line is etched in the front of medium substrate.

2. a kind of differential feed size three-frequency planar antenna according to claim 1, which is characterized in that the antenna radiation unit For axially symmetric structure, symmetry axis is horizontally through the center of antenna radiation unit.

3. a kind of differential feed size three-frequency planar antenna according to claim 1, which is characterized in that two intermediate frequency oscillators pass through Coplanar microstrip line is in parallel with low-frequency vibrator, and intermediate frequency oscillator one end is bent to the opposite direction of low-frequency vibrator.

4. a kind of differential feed size three-frequency planar antenna according to claim 1, which is characterized in that two high frequency oscillators pass through Coplanar microstrip line is in parallel with intermediate frequency oscillator, and high frequency oscillator one end is bent to the direction of low-frequency vibrator.

5. a kind of differential feed size three-frequency planar antenna according to claim 1, which is characterized in that the feed microstrip line knot Structure is metal stub, symmetrical about antenna radiation unit, parallel with low-frequency vibrator long side.

6. a kind of differential feed size three-frequency planar antenna according to claim 1, which is characterized in that feed microstrip line structure Characteristic impedance is 50 Ω.