CN103367916A - Multi-mode multi-frequency circularly-polarized satellite positioning receiving antenna - Google Patents

Abstract

The invention discloses a multi-mode multi-frequency circular polarization satellite positioning receiving antenna, which mainly solves the problem that the existing microstrip antenna cannot realize multi-frequency point reception by using a single radiation patch. The antenna is mainly composed of three dielectric plates stacked from bottom to top, wherein the first dielectric plate (1) is provided with a bottom plate electrode piece (4) and a feed network (5), and the second dielectric plate (2) is There are two feeding electrode sheets (6), the third dielectric plate (3) is provided with a radiation electrode sheet (7), the signal input end of the feeding network (5) is connected to the communication module of the external positioning terminal, and the signal The output end is connected to two feeding electrode sheets (6) through a set of probes (8), and the energy is transmitted to the radiation sheet (7) through double-point coupling to realize multi-frequency point reception. The invention not only has better symmetry and circular polarization characteristics at high and low frequency ends, but also can ensure the impedance bandwidth of the antenna, and has the advantages of simple structure and small volume of the antenna.

Description

Multi-mode multi-frequency circular polarization satellite positioning receiving antenna

technical field

The invention belongs to the technical field of wireless communication signal receiving equipment, and relates to a multi-mode and multi-frequency circular polarization satellite positioning receiving antenna.

Background technique

Traditional satellite positioning receiving antennas include microstrip antennas, crossed dipole antennas, and four-arm helical antennas. Microstrip antennas have the advantages of small size, light weight, and low profile, so they are widely used. However, most of the existing microstrip antennas work in single-mode or narrow-band mode. Ordinary single-radiation patches can only achieve one frequency point reception, and cannot achieve multi-frequency points, that is, they can only receive GPS, Beidou BD or GLONASS For a satellite system signal in GLONASS, if multi-frequency operation is realized, multiple radiation patches are required and a stacking method is adopted, and its pattern is not very ideal, so the application is limited to a certain extent.

Microstrip antennas can implement circular polarization by using single-point feed, dual-point feed or multi-point feed. The single-point feed generally has a narrow bandwidth, and the bandwidth of a common single-point feed network is only about 10%, so the broadband effect is difficult to achieve, while the multi-point feed network is more complicated.

In addition, the existing microstrip antenna network feeds the radiating elements directly with probes, which will introduce inductive reactance. If the radiating patch is too thick, the inductive reactance will be too large to compensate, which will make the impedance bandwidth of the antenna It is difficult to match due to shrinkage. At the same time, the direct feeding of the probe also increases the complexity of the process, and the size of the structure is large, which limits the use of the antenna.

Contents of the invention

The main purpose of the present invention is to provide a multi-mode multi-frequency circularly polarized satellite positioning receiving antenna, which solves the problem that the existing satellite microstrip receiving antenna cannot realize multi-frequency point reception when a single-radiation patch is used, and when a single-point feed is used. The defects of narrow bandwidth and narrow antenna impedance bandwidth when the probe is directly fed, complex process structure and large size.

In order to achieve the purpose of the invention, the present invention includes a dielectric board, a radiation patch, a feed network and a probe, and is characterized in that:

The dielectric board adopts the first dielectric board, the second dielectric board and the third dielectric board stacked together from bottom to top; the top surface of the first dielectric board is provided with a bottom plate electrode sheet, and the top surface of the second dielectric board is There are two feeding electrode sheets, the second electrode sheet is respectively connected to the two probes of the first group, the two signal output ends of the feeding network are respectively connected to the two probes of the first group, and the radiation electrode sheet It is arranged on the top surface of the third dielectric plate, and couples radiant energy through the feeding electrode sheet;

The feed network is arranged on the bottom surface of the first dielectric board, and the feed network is provided with two sets of short-circuit and open-circuit matching branches, and the short-circuit ends of the matching branches are connected to one end of the second group of two probes, The other ends of the two probes pass through the thickness direction of the first dielectric plate and are connected to the electrode pads of the bottom plate.

Preferably, the first dielectric plate and the second dielectric plate adopt a microstrip structure.

Preferably, the signal input end of the feed network is connected to the communication module of the external positioning terminal through a coaxial cable, the core wire of the coaxial cable is connected to the signal input end of the feed network, and the coaxial cable The outer layer conductor is connected with the electrode sheet of the bottom plate.

Preferably, the radiation patch is a circular patch.

Preferably, the bottom plate electrode sheet covers the entire top surface of the first dielectric plate.

Preferably, the feeding electrode sheet adopts a rectangular sheet.

Preferably, the first dielectric board is rectangular, and the second dielectric board and the third dielectric board are both square.

The present invention has the following advantages:

1) Since the present invention adopts the three-layer dielectric board stacked together from bottom to top, by coupling radiation energy, the antenna only needs one feed connector, and multi-frequency point reception can be realized through a single radiation patch, and in Both the high and low frequency end have good symmetry and good half-space radiation characteristics, the absolute gain is >2.5dBi, the high and low frequency axial ratio is less than 3dB, and has good circular polarization characteristics;

2) In the present invention, there are two sets of short-circuit and open-circuit combination matching branches on the feeding network, and the two signal output ends of the feeding network are respectively connected to the feeding electrode sheets through the probes. This dual-point feeding method and Optimized matching branches, so that the network bandwidth exceeds 40%;

3) In the present invention, the impedance bandwidth of the antenna can be guaranteed because the radiation patch and the feeding electrode sheet are fed in a coupling manner. At the same time, since the feeding electrode sheet is set to two, the dual-point coupling feeding process has a simple structure , and the size is small, which expands the use range of the antenna.

Description of drawings

Fig. 1 is the sectional structure schematic diagram of the present invention;

Fig. 2 is a schematic diagram of the structure of the top surface of the first dielectric plate in the present invention;

Fig. 3 is a schematic diagram of the structure of the bottom surface of the first dielectric plate in the present invention;

Fig. 4 is a schematic diagram of the structure of the top surface of the second dielectric board in the present invention;

Fig. 5 is a schematic diagram of the structure of the top surface of the third dielectric board in the present invention;

Fig. 6 is a working principle diagram of the feed network in the present invention;

Fig. 7 is the equivalent circuit diagram of the feed network among the present invention;

Fig. 8 is the standing wave ratio measured figure of the present invention in the 1176MHZ～1609MHZ frequency band;

Fig. 9 is the normalized measured pattern of the present invention at f=1176.45MHZ;

Fig. 10 is the normalized measured pattern of the present invention at f=1609MHZ;

Fig. 11 is an actual measurement diagram of the axial ratio of the antenna in the present invention.

Detailed ways

Referring to Fig. 1, Fig. 2, Fig. 3, Fig. 4, the present invention mainly consists of a first dielectric plate 1, a second dielectric plate 2, a third dielectric plate 3, a bottom plate electrode sheet 4 and a group of feed electrode sheets 6, feeding The network 5, the radiation electrode sheet 7, and two sets of probes 8 and 10 are composed. in:

The bottom plate electrode sheet 4 is arranged on the top of the first dielectric plate 1, as shown in Figure 2;

Z₂=2.51Z₀,Z₃=1.24Z₀。Wilkinson功分器和90°相位比较器由连续弯折的微带线构成，在介质板材料确定的条件下，微带线的线宽只取决于微带线的阻抗，可由以下公式换算出线宽w：The feed network 5 is arranged on the bottom surface of the first dielectric board 1, as shown in Figure 3, the signal input end of the feed network 5 is connected to the communication module of the external positioning terminal, and the signal output end of the feed network 5 is divided into two routes And each path is respectively connected to the first group of probes 8 , and the first group of probes 8 passes through the thickness direction of the first dielectric plate 1 and the second dielectric plate 2 and is respectively connected to a group of feeding electrode sheets 6 . The feeding network 5 of this example is preferably but not limited to a 90° broadband power divider, which includes a Wilkinson power divider, a 90° phase comparator and a set of matching stubs 9 , the principle of which is shown in FIG. 6 . Among them, the impedance connected to input port 1 is Z ₁ , the matching branch impedance is Z ₂ , the intermediate impedance is Z ₃ , and the standard impedance is Z ₀ =50Ω,

Z ₂ =2.51Z ₀ , Z ₃ =1.24Z ₀ . The Wilkinson power divider and the 90° phase comparator are composed of continuously bent microstrip lines. Under the condition that the dielectric plate material is determined, the linewidth of the microstrip line only depends on the impedance of the microstrip line. The linewidth can be converted by the following formula w:

$\mathrm{<span\; class="notranslate">\; Z</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; Z</span>}}_{\mathrm{<span\; class="notranslate">\; w</span>}}}{\sqrt{{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; eff</span>}}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1.393</span>}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; w</span>}}{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; 3</span>}}\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; w</span>}}{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1.444</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>}$

为介质的有效介电常数，h为介质板的厚度。Among them, Z _w =376.8Ω, is the wave impedance in free space,

is the effective dielectric constant of the medium, and h is the thickness of the dielectric plate.

The open-circuit ends of the group of matching branches 9 are open-circuited on the surface of the medium, and the short-circuit ends are respectively connected to the second group of probes 10, and the two probes 10 pass through the thickness direction of the first dielectric plate 1 and are connected to the electrode sheet 4 of the bottom plate. , the circuit principle is shown in Figure 7, the matching branch adopts λ/8 open line and λ/8 short line, λ is the effective wavelength in the medium, the terminal impedance of the open line is equivalent to infinity, and the terminal impedance of the short line is equivalent to 0 , according to the impedance characteristics of the transmission line, it can be obtained that the impedance of the λ/8 short circuit is inductive, and the impedance of the λ/8 open line is capacitive. By connecting inductance and capacitance in parallel, it can play the role of phase compensation, so as to realize the requirement that the phase difference is 90° in the entire frequency band, and realize a broadband network. According to the analysis of odd and even modes, in the case of satisfying VSWR<1.5 and a relative phase difference of 2°, the 90° phase comparator can theoretically obtain a maximum bandwidth of 70%.

Two feeding electrode sheets 6 are arranged on the top of the second dielectric plate 2 and connected to the signal output end of the feeding network 5 through a set of probes 8 , as shown in FIG. 4 .

The radiation patch 7 is arranged on the top of the third dielectric plate 3, preferably a circular patch, as shown in FIG. 5 .

The first dielectric plate, the second dielectric plate and the third dielectric plate are stacked sequentially from bottom to top, and the first dielectric plate and the second dielectric plate adopt a microstrip structure. During specific implementation, the first dielectric plate 1 is a rectangular plate with a dielectric constant of 6.3, its aspect ratio is 9:10, and the preferred length and width are 45mm and 50mm respectively. The second dielectric plate 2 and the third dielectric plate 3 are dielectric A square plate with a constant of 14 has a side length of 45mm. The thickness of the first dielectric plate 1 is preferably 1 mm, the thickness of the second dielectric plate 2 is preferably 6.5 mm, and the thickness of the third dielectric plate 3 is preferably 10.5 mm. The ratio of the thickness of the first dielectric plate 1 to the sum of the thicknesses of the second dielectric plate 2 and the third dielectric plate 3 is 1:17. The bottom plate electrode sheet 4 covers the entire top surface of the first dielectric plate 1. The two feed electrode sheets 6 are rectangular sheets with a length and width of 13 mm and 2 mm respectively. The radiation electrode sheet 7 is a circular sheet with a diameter of 20 mm. A two-point coupling feeding method is adopted between each feeding electrode sheet 6 and the radiation electrode sheet 7 . This is because the frequency band can be broadened by increasing the thickness of the antenna dielectric substrate. However, as the thickness increases, the length of the probe also increases correspondingly. Too long probes will introduce inductive reactance, thereby reducing the impedance bandwidth of the antenna. To solve this feeding problem, the present invention adopts double-point coupling, which is a close-coupling method, for feeding, so that the energy is coupled from the feeding electrode sheet 6 to the radiation electrode sheet 7, thereby radiating out.

All electrode sheets and feed network 5 of the present invention are preferably made of silver electrode sheets. Preferably, a coaxial cable is used to connect to the communication module of the external positioning terminal. The core wire of the coaxial cable is connected to the signal input end of the feeding network 5 , and the outer conductor of the coaxial cable is connected to the bottom plate electrode sheet 4 .

Effect of the present invention can be illustrated by the following measured data:

Test 1: The working frequency band of the antenna is 1176MHZ～1609MHZ, and its standing wave ratio is tested with Agilent 8753ES in the microwave anechoic chamber. VSWR≤2:1.

Test 2: Measure the stereo pattern of the antenna in the Airlink3D microwave anechoic chamber. The measured results are shown in Figure 9 and Figure 10, where Figure 9 is the normalized measured pattern of f=1176.45MHZ, and Figure 10 is the normalized pattern of f=1609MHZ Measured direction map. It can be seen more intuitively from the directional diagrams in Fig. 9 and Fig. 10 that the antenna of the present invention has better symmetry at both high and low frequency ends, reflects good half-space radiation characteristics, and has an absolute gain > 2.5dBi.

Test 3: In the microwave anechoic chamber, test the half-space circular polarization axis ratio of the antenna working at the highest center frequency point and the lowest center frequency point by repeatedly rotating the one-line polarized horn antenna for one week, as shown in Figure 11. It can be seen from FIG. 11 that the axial ratio of the antenna of the present invention is 3db, showing a good circular polarization effect.

The basic principles, main features and advantages of the present invention have been shown and described above. The above-mentioned embodiments and descriptions are only the principles of the present invention. The present invention also has various changes and changes without departing from the spirit and scope of the present invention. Improvements, such changes and improvements are within the scope of the claimed invention.

Claims (7)

1. a multimode multi-frequency polarized satellite fix reception antenna comprises dielectric-slab, radiation electric pole piece (7), feeding network (5) and probe, it is characterized in that:

Described dielectric-slab adopts the first medium plate (1), second medium plate (2) and the 3rd dielectric-slab (3) that are superimposed together from bottom to top; The end face of first medium plate (1) is provided with bottom plate electrode sheet (4), the end face of second medium plate (2) is provided with two feed electrode slices (6), this feed electrode slice links to each other with an end of first group two probes (8) respectively, two signal output parts of feeding network (5) are connected with the other end of first group two probes (8) respectively, radiation electric pole piece (7) is arranged on the end face of the 3rd dielectric-slab (3), by feed electrode slice (6) coupled radiation energy;

Described feeding network (5), be arranged on the bottom surface of first medium plate (1), be provided with two groups of coupling minor matters (9) on this feeding network, the short-circuit end of every group of coupling minor matters (9) is connected with an end of second group two probes (10), and the thickness direction that the other end of these two probes (10) passes first medium plate (1) is connected with bottom plate electrode sheet (4).

2. multimode multi-frequency polarized satellite fix reception antenna as claimed in claim 1 is characterized in that, first medium plate (1) and second medium plate (2) adopt microstrip structure.

3. multimode multi-frequency polarized satellite fix reception antenna as claimed in claim 1, it is characterized in that, the signal input part of feeding network (5) is connected with the communication module of outside locating terminal by coaxial cable, the heart yearn of coaxial cable is connected on the signal input part of feeding network (5), and the outer contact of coaxial cable is connected with bottom plate electrode sheet (4).

4. multimode multi-frequency polarized satellite fix reception antenna as claimed in claim 1 is characterized in that, radiation electric pole piece (7) adopts circular patch.

5. multimode multi-frequency polarized satellite fix reception antenna as claimed in claim 1 is characterized in that, bottom plate electrode sheet (4) covers the end face of whole first medium plate (1).

6. multimode multi-frequency polarized satellite fix reception antenna as claimed in claim 1 is characterized in that, feed electrode slice (6) adopts rectangular sheet.

7. multimode multi-frequency polarized satellite fix reception antenna as claimed in claim 1 is characterized in that, first medium plate (1) is rectangle, and second medium plate (2) and the 3rd dielectric-slab (3) are square.

Images