CN105161837A - A Miniaturized Coplanar Waveguide-fed Broadband Printed Antenna - Google Patents

Abstract

The invention relates to a miniaturized coplanar waveguide (CPW) feed broadband printed antenna, which comprises a first U-shaped monopole, a second U-shaped monopole, a CPW feed line, a CPW gap and a dielectric substrate, wherein the first U-shaped monopole is connected with the second U-shaped monopole through the CPW feed line; the invention simultaneously excites the three radiation units, namely the low frequency band is the first U-shaped monopole and the second U-shaped monopole are used as main radiation bodies, the middle frequency band is the first U-shaped monopole is used as a main radiation body, and the high frequency band is the CPW feeder line which is used as a main radiation body, thereby expanding the working bandwidth of the antenna. The invention has the advantages of simple antenna structure, miniaturization, wide frequency band and stable radiation pattern in the whole frequency band, and is suitable for broadband communication systems represented by high-speed wireless personal area networks and broadband wireless local area networks, and other antenna designs with higher requirements on the stability of the direction pattern in the frequency band and the bandwidth.

Description

A Miniaturized Coplanar Waveguide-fed Broadband Printed Antenna

technical field

The invention belongs to the technical field of antenna design of wireless communication technology, and relates to a miniaturized coplanar waveguide feeding broadband printed antenna with stable in-band pattern for reliable communication.

Background technique

With the rapid development of modern wireless communication technology, electromagnetic waves, as the carrier of information transmission, are playing an increasingly important role. Antenna, as a device for radiating or receiving radio waves in radio equipment, is widely used in radio communication equipment, radar, electronic countermeasure equipment and radio navigation equipment.

Broadband and ultra-broadband wireless technology, due to its advantages of high transmission rate and large system capacity, has been widely used in many fields such as high-speed wireless personal area network, intelligent wireless local area network, outdoor peer-to-peer network, and sensing, positioning and identification network. . With the rapid development of the mobile communication industry in the world, the mobile communication system is constantly evolving. The mobile communication system has developed from the third-generation WCDMA, CDMA2000, and TD-SCDMA mobile communication systems to the fourth-generation broadband wireless mobile communication network IMT-Advanced system that is widely used. The European Commission stated in December 2013 that it would cooperate with enterprises to allocate 700 million euros and more than 3 billion euros for the research and development of the fifth generation (5G) mobile communication system. The fifth-generation mobile communication system will provide brand-new technologies to establish connections between people, people and cars anywhere, and plans to implement 5G applications in 2020. my country invested 160 million yuan in 2013 to start the National 863 Program "Preliminary Research and Development of the Fifth Generation Mobile Communication (5G) System (Phase I)" project, "to systematically study the architecture of 5G mobile communication system, wireless networking, wireless transmission , new antennas and radio frequencies, and key technologies for the development and utilization of new spectrum.” The rapid increase in the number of mobile users and the sharp increase in the amount of user data pose a huge challenge to the capacity and update of mobile communication systems.

In order to meet the communication requirements of multiple systems at the same time, to achieve multi-system sharing and transceiver sharing, and to reduce the interference between antennas and reduce costs, the current relatively mature technology requires a single antenna to work in a wide frequency range. By exciting the high-order modes of a single antenna, the single antenna works in multiple resonance modes, thereby expanding the bandwidth. A typical example is a monopole antenna. This antenna has a simple structure, low processing cost, and can realize a bandwidth of several octaves. However, the monopole antenna works in the monopole mode within the entire bandwidth, and the radiation pattern is sensitive to the electrical length of the monopole. Considering that the bandwidth of broadband and ultra-wideband antennas is very wide, it can often reach several octaves, so the electrical size of the monopole changes several times in the octave, so its radiation pattern is very distorted in the octave Serious, and the higher the frequency, the more obvious the distortion. This problem exists for single antennas with multiple resonant modes. In order to improve the effectiveness of the wireless communication system and ensure the reliability of the wireless communication system, and to reduce the cost of the antenna, a planar antenna that maintains a stable radiation pattern in broadband and ultra-wideband is designed, which is of great significance to the development of broadband wireless communication. Very positive contribution.

Contents of the invention

The technical problem to be solved by the present invention is to provide a miniaturized coplanar waveguide-fed broadband printed antenna with a stable pattern in the working frequency band in view of the above-mentioned prior art.

The technical solution adopted by the present invention to solve the above problems is: a miniaturized coplanar waveguide-fed broadband printed antenna, comprising:

The first U-shaped monopole (1) is composed of three microstrip lines with the same width connected in sequence;

The second U-shaped monopole (2) is composed of three microstrip lines with the same width connected sequentially;

The CPW feeder (3) is a section of microstrip line, the lower arm (1a) of the first U-shaped monopole (1) and the lower arm (2a) of the second U-shaped monopole (2) are symmetrical about its mirror image;

The CPW slot (4), consisting of two slots with the same length and width, is mirror-symmetrical about the CPW feeder (3);

The dielectric substrate (5), the first U-shaped monopole (1), the second U-shaped monopole (2), the CPW feeder (3), and the CPW slit (4) are all arranged on one side thereof.

The lower arm of the first U-shaped monopole and the lower arm of the second U-shaped monopole simultaneously serve as the metal floor of the CPW feed structure.

The lower arm of the first U-shaped monopole and the lower arm of the second U-shaped monopole and the two CPW slots are mirror-symmetrical with respect to the CPW feeder.

The microstrip lines forming the first U-shaped monopole and the second U-shaped monopole have the same width.

Adjust the parameter values of the first U-shaped monopole, the second U-shaped monopole, CPW feeder, and CPW gap to match the working mode and impedance of the monopole in each frequency band, so the impedance of the entire antenna can be used in each frequency band Adjust it to 50 ohms to match the entire antenna with the coaxial feed port at the input end.

The CPW feeder is connected to the coaxial probe, and the coaxial probe is used for feeding.

Compared with the prior art, the present invention has the advantages of:

(1) The antenna structure is simple and the manufacturing cost is low.

(2) It proposes to excite three radiating units at the same time, resonate in different working frequency bands, expand the working bandwidth of the antenna, and meet the bandwidth requirements of the broadband wireless communication system.

(3) The monopole working mode with the same pattern is adopted, so that the antenna has stable electromagnetic radiation direction characteristics in the entire working frequency band, ensuring the stability and reliability of broadband wireless communication.

Description of drawings

FIG. 1 is a top view of an implementation example of the antenna in the present invention, and the units of dimensions marked on the figure are millimeters (mm).

FIG. 2 is a side view of an implementation example of the antenna in FIG. 1 , and the units of dimensions marked on the figure are millimeters (mm).

Figure 3 is a simulation diagram of the reflection coefficient of the implementation example of the antenna in Figure 1, where: Indicates the simulated reflection coefficient.

Figure 4 is the radiation pattern of the antenna in Figure 1, Figure 4(a) is the antenna working at 2GHz, Figure 4(b) is the antenna working at 3GHz, and Figure 4(c) is the antenna working at 4.44GHz, where: Represents the simulated radiation pattern.

Figure 5 is a simulation diagram of the antenna gain in Figure 1, where: Indicates the simulated gain value.

in:

A first U-shaped monopole 1 , a second U-shaped monopole 2 , a CPW feeder 3 , a CPW slot 4 , and a dielectric substrate 5 .

detailed description

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

As shown in Figure 1, a top view of a miniaturized coplanar waveguide-fed broadband printed antenna in this embodiment, the antenna structure includes a first U-shaped monopole 1, a second U-shaped monopole 2, and a CPW feeder 3 , CPW gap 4, dielectric substrate 5. Both the first U-shaped monopole 1 and the second U-shaped monopole 2 are connected in sequence by three microstrip lines with the same width, and the first U-shaped monopole 1 and the second U-shaped monopole 2 are microstrip The stripline widths are the same.

The CPW feeder 3 is connected to the coaxial probe, and the coaxial probe is used for feeding.

The lower arm 1a of the first U-shaped monopole 1 and the lower arm 2a of the second U-shaped monopole 2 also serve as the metal floor of the CPW feed structure.

As shown in FIGS. 1 and 2 , the dielectric substrate 5 is made of FR4 plate with a relative permittivity of 4.4 and a thickness of 1.6 mm. The first U-shaped monopole 1 , the second U-shaped monopole 2 , the CPW feeder 3 , and the CPW slot 4 are all arranged on the same surface of the dielectric substrate 5 .

The technical solution of the present invention is achieved in this way: with the structure shown in Figure 1 and Figure 2, when the antenna works in a lower frequency band, the first U-shaped monopole 1 and the second U-shaped monopole 2 together serve as the main Radiator, the antenna works in monopole mode, adjust the total length of the first U-shaped monopole 1 and the second U-shaped monopole 2, the first U-shaped monopole 1 and the second U-shaped monopole 2 The relative position and length of the gap and the broadband of the microstrip line can adjust the operating frequency and impedance matching of the low frequency band. At this time, the current distribution is concentrated on the first U-shaped monopole 1 and the second U-shaped monopole 2. As shown in Figure 1 and Figure 2, when the antenna works in the middle frequency band, the first U-shaped monopole 1 is used as the main radiator, and the antenna works in the monopole mode, and the first U-shaped monopole 1 is adjusted. The length and width of the microstrip line can adjust the working frequency and impedance matching of the intermediate frequency band, and the current distribution is concentrated on the first U-shaped monopole 1. As shown in Figure 1 and Figure 2, when the antenna works in a higher frequency band, the antenna works in a monopole mode, and the length and width of the CPW feeder 3 can be adjusted to adjust the operating frequency and impedance matching of the monopole mode. The current distribution is concentrated on the CPW feeder 3, and the length of the part of the CPW feeder 3 protruding from the metal floor is about a quarter wavelength. Therefore, by adjusting the parameters of the antenna, three radiating units can be excited, that is, the low frequency band is the first U-shaped monopole 1 and the second U-shaped monopole 2 as the main radiator, and the middle frequency band is the first U-shaped monopole The sub-1 is the main radiator, and the CPW feeder 3 is the main radiator in the high-frequency band, thus expanding the working bandwidth of the antenna; since the antenna is in the monopole working mode in the low-frequency band, mid-frequency band and high-frequency band, it has similar antenna radiation Figure, so the present invention has stable two-way radiation characteristics in the entire working frequency band. The specific result of the embodiment of the invention is described as follows:

The dimensions of the antenna can be shown in Figure 1 and Figure 2: the width of the microstrip line forming the first U-shaped monopole (1) and the second U-shaped monopole 2 is both 8.8mm. The outer length of the lower arm 1a of the first U-shaped monopole 1 is 27.1 mm, the outer length of the other arm is 16.7 mm, and the inner length of the middle section is 27.4 mm. The outer length of the lower arm 2a of the second U-shaped monopole 2 is 27.1 mm, the outer length of the other arm is 34.7 mm, and the inner length of the middle section is 27.4 mm. The gap between the upper arm of the first U-shaped monopole (1) and the upper arm of the second U-shaped monopole (2) is 6mm long. The length of the CPW feeder 3 is 25.6 mm, and the width is 1.2 mm. Both CPW gaps 4 have a width of 1mm. The length of the dielectric substrate 5 is 45mm, the width is 57.4mm, and the thickness is 1.6mm. The simulation results of the reflection coefficient of the antenna made according to the above dimensions are shown in Figure 3, the -10dB bandwidth is 3.6087GHz, from 1.7866GHz to 5.3953GHz. The simulation results of the radiation pattern of the antenna made with the dimensions shown in Figure 1 and Figure 2 are shown in Figure 4, where Figure 4(a) is the radiation pattern of the X-Y plane and Y-Z plane when the antenna works at 2GHz; Figure 4(b ) is the radiation pattern of X-Y plane and Y-Z plane when the antenna works at 3GHz; Figure 4(c) is the radiation pattern of X-Y plane and Y-Z plane when the antenna works at 4.44GHz. It can be seen that at a given frequency, the antennas have stable two-way radiation characteristics. We define the 3-dB beamwidth of an antenna at different frequencies as the sum of the 3-dB beamwidths in both directions (+Y and -Y). As shown in Figure 4(a), when the antenna works at 2GHz, the X-Y plane has a 3-dB beamwidth of 150°; the Y-Z plane has a 3-dB beamwidth of 110°. As shown in Figure 4(b), when the antenna works at 3GHz, the X-Y plane has a 3-dB beamwidth of 150°; the Y-Z plane has a 3-dB beamwidth of 155°. As shown in Figure 4(c), when the antenna works at 4.44GHz, the X-Y plane has a 3-dB beamwidth of 100°; the Y-Z plane has a 3-dB beamwidth of 120°. It can be seen that the 3-dB beamwidth of the antenna is very wide. The gain of the antenna made with the dimensions shown in Figure 1 and Figure 2 is shown in Figure 5. In the 1.78GHz to 5.40GHz frequency band, the antenna gain fluctuates from 3.65dB to 7.18dB.

The antenna system can realize a bandwidth of 3.6087GHz (from 1.7866GHz to 5.3953GHz) in a plane space of 45×57.4mm ² , and has stable bidirectional radiation characteristics in the entire working frequency band.

In addition to the above-mentioned embodiments, the present invention also includes other implementations, and any technical solution formed by equivalent transformation or equivalent replacement shall fall within the protection scope of the claims of the present invention.

Claims (5)

1. the coplanar waveguide feed wideband printed antenna of miniaturization, it is characterized in that, it comprises:

First U-shaped monopole (1), the microstrip line identical by three width connects to form successively;

Second U-shaped monopole (2), the microstrip line identical by three width connects to form successively;

CPW feeder line (3) is one section of microstrip line, and the first U-shaped monopole (1) underarm (1a) and the second U-shaped monopole (2) underarm (2a) are about its specular;

CPW gap (4), the gap all identical with width by two length forms, about CPW feeder line (3) specular;

Medium substrate (5), described first U-shaped monopole (1), the second U-shaped monopole (2), CPW feeder line (3), CPW gap (4) are all arranged at its one side.

2. the miniaturized coplanar waveguide feed wideband printed antenna of one according to claim 1, is characterized in that, the first U-shaped monopole (1) underarm (1a), the second U-shaped monopole (2) underarm (2a) are simultaneously as the metal floor of CPW feed structure.

3. the miniaturized coplanar waveguide feed wideband printed antenna of one according to claim 1, is characterized in that, forms the first U-shaped monopole (1) identical with the micro belt line width of the second U-shaped monopole (2).

4. the miniaturized coplanar waveguide feed wideband printed antenna of one according to claim 1, it is characterized in that, adjust the first U-shaped monopole (1), the second U-shaped monopole (2), CPW feeder line (3), CPW gap (4) each parameter value, each frequency range monopole mode of operation and impedance matching can be made, therefore the impedance of whole antenna is all adjustable as 50 ohm in each frequency band, realizes mating of whole antenna and input coaxial feed port.

5. the miniaturized coplanar waveguide feed wideband printed antenna of one according to claim 1, is characterized in that, CPW feeder line (3) is connected with coaxial probe, uses coaxial probe to carry out feed.