CN113193366B - Double-frequency printed dipole antenna based on common-arm structure - Google Patents

Abstract

The invention provides a dual-frequency printed dipole antenna based on a common-arm structure, which comprises the following components: an upper arm and a lower arm; the upper arm is a binary array antenna coupled with the high frequency band; the lower arm is of a red copper tubular structure; the upper arm and the lower arm are connected through a feed port; a matching inductor is loaded on one side of the feed port, which is close to the lower arm; a high-frequency coupling capacitor is loaded on one side of the feed port close to the upper arm; the feed port is connected to the SMA-J antenna interface through a coaxial feed line; the whole antenna body is packaged by a transparent antenna housing; the invention realizes simultaneous operation of two frequency bands with larger span on one antenna, the low frequency band is used for electromagnetic wave energy collection, the high frequency band is used for wireless communication, the problems of fast attenuation of high-frequency electromagnetic wave energy and low-frequency communication rate are solved, and the invention has wide application prospect in the field of passive Internet of things communication.

Description

A Dual-frequency Printed Dipole Antenna Based on Co-arm Structure

technical field

The invention relates to the field of electromagnetic wave energy collection, in particular to a dual-frequency printed dipole antenna based on a co-arm structure.

Background technique

As a basic antenna type, omnidirectional antenna has a wide range of applications. It is applied to form wireless spread spectrum network, point-to-point communication, data transmission and so on.

Printed dipole antennas are especially favored by the industry due to their low cost, light weight, small form factor, and ease of processing. In the design of printed dipole antenna, broadband, miniaturization and high gain are key technical requirements. The most unique feature of the printed dipole is that its structure simply consists of two arms printed on either side of a dielectric substrate.

By properly adjusting these arms, its resonant frequency and bandwidth can meet our different needs.

Many dual-band and multi-band printed dipoles have been reported in many works. Etching slits on the radiator or ground plane is one of the common methods to obtain multiple frequency bands.

Another classic solution is to put antennas working in different frequency bands together. However, it requires a matching circuit, which complicates the design.

A third solution is to add strips to the slots. In addition, by introducing various bandgap structures, the antenna can also obtain multiple frequency bands. In recent years, with the development of material science, metamaterials have been widely used in multiband antenna design.

Contents of the invention

In view of this, the present invention proposes a dual-frequency printed dipole antenna based on a co-arm structure, and the operating frequencies are 433Mhz and 2390Mhz respectively. Through the loading of capacitance and inductance, a compact size of 240mm×8mm×0.5mm is obtained. Simulation and measurement results are given and discussed. Simulations were performed using Ansoft HFSS 18.0 full-wave simulator. The simulation results are in good agreement with the measured results.

The present invention provides a dual-frequency printed dipole antenna based on a co-arm structure, the main body of which is a low-frequency dipole antenna, including:

upper and lower arms;

The upper arm is a binary array antenna coupled to the high frequency band, which is one arm of the low-frequency printed dipole antenna; the lower arm is a copper tubular structure, which is the other arm of the low-frequency printed dipole antenna, and forms a low-frequency dipole together with the upper arm antenna;

The upper arm and the lower arm are connected through the feed port;

The side of the feed port close to the lower arm is loaded with a matching inductance;

The side of the feed port close to the upper arm is loaded with a high-frequency coupling capacitor;

The feed port is connected to the SMA-J antenna interface through a coaxial feeder;

The whole antenna body is encapsulated by a transparent radome.

Further, the antenna works in the 433MHz and 2390MHz frequency bands simultaneously.

The length L ₁ of the antenna is 240mm, and the width W ₁ is 8mm; the length of the two columns of the binary array antenna is L ₄ : 30mm; the width of the two columns of the binary array antenna is W ₂ : 1mm; the end of the binary array antenna The length L ₅ is 9mm; the length L ₃ of the lower arm is 90mm; the inductance of the matching inductor is 22nH; the capacitive reactance of the high frequency coupling capacitor is 3.9pF.

The beneficial effects provided by the present invention are: the simultaneous operation of two large-span frequency bands is realized on one antenna, the low-frequency band is used for electromagnetic wave energy collection, and the high-frequency band is used for wireless communication, which solves the problem of fast attenuation of high-frequency electromagnetic wave energy and low-frequency communication It has a wide application prospect in the field of passive Internet of Things communication.

Description of drawings

Fig. 1 is a structural diagram of a dual-frequency printed dipole antenna based on a co-arm structure of the present invention;

Fig. 2 is a dimensional drawing of the dual-frequency printed dipole antenna based on the co-arm structure of the present invention;

Figure 3 is a schematic diagram of the influence of the value of the load matching inductor and its position on the direction of VSWR;

Figure 4 shows the effect of antenna sizes L2 and L5 on VSWR;

Fig. 5 is the simulation result of the voltage standing wave coefficient of the electromagnetic collection antenna;

Figure 6 is the simulation result of the Smith impedance circle.

Detailed ways

In order to make the purpose, technical solution and advantages of the present invention clearer, the embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

Please refer to Figure 1, a dual-frequency printed dipole antenna based on a common arm structure, including the following:

upper arm 2 and lower arm 1;

The upper arm 2 is a binary array antenna coupled to the high-frequency band, which is one arm of the low-frequency printed dipole antenna; the lower arm 1 is a copper tubular structure, which is the other arm of the low-frequency printed dipole antenna, and together with the upper arm 2 constitutes a low-frequency dipole antenna;

The upper arm 2 and the lower arm 1 are connected through the feed port 3;

The side of the feed port 3 close to the lower arm is loaded with a matching inductor 4;

The side of the feed port 3 close to the upper arm is loaded with a high-frequency coupling capacitor 5;

The feed port 3 is connected to the SMA-J antenna interface 6 through a coaxial feeder 7;

The entire antenna body is encapsulated by a transparent radome 8 .

Please refer to FIG. 2, which is a dimensional drawing of the dual-frequency printed dipole antenna based on the co-arm structure of the present invention;

Figure 2 disassembles the package in Figure 1.

The leftmost side of Figure 2 is the dielectric substrate disassembled after the antenna is packaged;

The relative permittivity of the dielectric substrate is ε _r =2.65, and the loss tangent angle is tanδ=0.005. The high-frequency oscillator arms on both sides of the dielectric substrate are placed opposite to each other. The high-pass characteristic of the capacitor makes the current on the ground oscillator not crosstalk to the radiation unit on the upper half of the dielectric substrate when the antenna works at low frequencies; the two sides are superimposed , which forms the encapsulation part in Figure 1;

With respect to FIG. 2 , the present invention uses a method of loading matching inductance to reduce the longitudinal size of the antenna, so the influence of the position of the inductance on the antenna is also analyzed. Figure 3 simulates the changes in the antenna pattern as the position of the inductor moves. According to the simulation results, the ANT.1 pattern has an upward trend, and the maximum gain point is no longer in the 90° direction.

In addition, in addition to the inductance, the size of the printed dipole (binary array antenna) will also greatly affect the performance of the antenna. The influence of the parameter L ₂ on the antenna is that as the L ₂ increases, the resonance point of the low frequency band moves to the low frequency. However, the high-band performance is relatively stable and basically not affected by it. Like _L2 , the increase of _L5 will also cause the low-frequency resonance point to move to a lower frequency, as shown in Figure 4. In Figure 4, the upper part is the influence of L ₂ ; the lower part is the influence of L ₅ ;

The present invention utilizes HFSS electromagnetic simulation software to simulate the dual-frequency printed dipole antenna model based on the co-arm structure, and simulates the difference of model parameters (i.e. size); preferably, the present invention is as follows to the parameter design of antenna size:

Table 1 Antenna size parameter list

The length L ₁ of the antenna is 240mm, and the width W ₁ is 8mm; the length of the two columns of the binary array antenna is L ₄ : 30mm; the width of the two columns of the binary array antenna is W ₂ : 1mm; the end of the binary array antenna The length L ₅ is 9mm; the length L ₃ of the lower arm 1 is 90mm; the inductance of the matching inductor 4 is 22nH; the capacitive reactance of the high frequency coupling capacitor 5 is 3.9pF.

Please refer to Figure 5-Figure 6, Figure 5 is the simulation result of the voltage standing wave coefficient of the electromagnetic collection antenna; Figure 6 is the simulation result of the Smith impedance circle;

The simulation results show that the antenna of this size exhibits obvious dual-frequency characteristics, and the VSWC is superior to 1.25 in both low-frequency and high-frequency bands. Moreover, according to the simulation results of the Smith impedance chart, the dual-band antenna can achieve excellent matching characteristics with the 50-ohm SMA RF port and its coaxial line in both frequency bands.

The beneficial effects of the present invention are: the simultaneous operation of two large-span frequency bands is realized on one antenna, the low-frequency band is used for electromagnetic wave energy collection, and the high-frequency band is used for wireless communication, which solves the problem of fast attenuation of high-frequency electromagnetic wave energy and low-frequency communication rate It has wide application prospects in the field of passive Internet of Things communication.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims (1)

1. The utility model provides a dual-frenquency printing dipole antenna based on common arm structure which characterized in that: comprising the following steps:

an upper arm (2) and a lower arm (1);

the upper arm (2) is a binary array antenna coupled with a high frequency band and is one arm of a low-frequency printed dipole antenna; the lower arm (1) is of a red copper tubular structure, is the other arm of the low-frequency printed dipole antenna, and forms a low-frequency dipole antenna together with the upper arm (2);

the upper arm (2) and the lower arm (1) are connected through a feed port (3);

a matching inductor (4) is loaded on one side of the feed port (3) close to the lower arm;

a high-frequency coupling capacitor (5) is loaded on one side of the feed port (3) close to the upper arm;

the feed port (3) is connected to the SMA-J antenna interface (6) through a coaxial feed line (7);

the whole antenna body is packaged by a transparent antenna housing (8);

the antenna works in 433MHz and 2390MHz frequency bands at the same time;

antenna length L ₁ 240mm, width W ₁ 8mm; the two columns of the binary array antenna are L in length ₄ :30mm; two rows of binary array antenna are W ₂ :1mm; end length L of binary array antenna ₅ 9mm; length L of lower arm (1) ₃ 90mm; the inductance of the matching inductor (4) is 22nH; the capacitive reactance of the high frequency coupling capacitor (5) is 3.9pF.

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