Load the broad beam circular polarization microstrip antenna of parasitic annulus
Technical field
The present invention relates to circular polarization satellite positioning navigation antenna, relate in particular to the broad beam circular polarization microstrip antenna that loads parasitic annulus.
Background technology
At present, the global positioning satellite navigation has become the industry of a high speed development, the service range of the triones navigation system that China is set up is voluntarily estimated in following 10 years covering the whole world, and as wireless communication system throat thoroughfare---circular polarized antenna plays crucial effects to this system.
According to the operation principle of satellite navigation system, in the middle of the signal of vertical plane, to system accuracy contribution maximum be low elevation signals near ground, though the zenith signal be easy to emission and receive, little to positioning action.Like this, in order to improve the positioning accuracy of system, generally require circular polarized antenna to have higher low elevation gain (being the vertical plane lobe width of broad), especially for present dipper system, satellite is fewer, low elevation gain to antenna has proposed harsh requirement, yet present flat circle poliarizing antenna ubiquity is because of the narrower problem that causes the low elevation gain deficiency of vertical plane lobe width.
Four-arm spiral antenna and plane microstrip antenna can form hemispheric circular polarization wave beam, are global position system two kinds of antenna structure forms commonly used.Four-arm spiral antenna has the vertical plane lobe width of broad, but its section is higher, and needs extra feeding network, complex structure, and operating efficiency is not high.
Microstrip antenna has obtained application more and more widely owing to have low section, easy of integration and advantage such as high conformity in batches.Generally speaking, the vertical plane lobe width of microstrip antenna is narrower, is about 70 °-90 °, is difficult to satisfy low elevation angle index request higher in the practical application.
In order to increase the vertical plane lobe width of microstrip antenna, the simplest way is the dielectric constant that reduces the size on floor and increase substrate, but the effect of these two kinds of methods is very limited, and can bring new problems such as operating efficiency decline, production difficulty and cost increase.In addition, can increase lobe width effectively, thereby improve low elevation gain, but can fundamentally change the characteristic of the low section of planar microstrip antenna by the method that loads the taper round platform.
Summary of the invention
The objective of the invention is to overcome the shortcoming and defect of above-mentioned prior art, the broad beam that loads parasitic annulus circular polarization microstrip antenna is provided; It is narrower to overcome conventional circular polarization antenna vertical plane lobe width, and directional diagram is difficult for the problem of adjusting.
The present invention is achieved through the following technical solutions:
Load the broad beam circular polarization microstrip antenna of parasitic annulus, comprise upper substrate, infrabasal plate,
Be provided with fixed leg between upper substrate and the infrabasal plate, the upper surface of described infrabasal plate is provided with the primary radiation unit, and the upper surface of upper substrate is provided with parasitic annulus chip unit, and the bottom surface of infrabasal plate is provided with the floor.
Be provided with excitation port between described primary radiation unit and the floor.
Described primary radiation unit is made up of a circular patch and a pair of rectangle outward flange projection that is positioned on the circular patch diameter.
Described outward flange projection is 45 ° with the angle that excitation port becomes in the place, the center of circle of circular patch.
Described primary radiation unit be shaped as in circle, ellipse, rectangle or the triangle any one.
The girth of described parasitic annulus chip unit is greater than two wavelength.
The present invention has following advantage and effect with respect to prior art:
1, when keeping the good radiance of planar microstrip circular polarized antenna, can widen the vertical plane lobe width effectively, thereby improve low elevation gain, and debugging is convenient.
2, compare with existing broad beam circular polarized antenna, the present invention has simpler structure, littler size, and lighter weight, thus can reduce production costs, be applicable in the various Miniature Terminal equipment.
Description of drawings
Fig. 1 is the parasitic annulus chip unit of the present invention structural representation.
Fig. 2 faces structural representation for the present invention.
Fig. 3 is a primary radiation cellular construction schematic diagram of the present invention.
Fig. 4 is that the present invention loads the corresponding respectively dextrorotation gain curve in parasitic annulus chip unit front and back.
Embodiment
Below in conjunction with specific embodiment the present invention is done further concrete detailed description the in detail.
Embodiment
As Fig. 1, Fig. 2, shown in Figure 3, the present invention loads the broad beam circular polarization microstrip antenna of parasitic annulus, comprise upper substrate 1, infrabasal plate 2, be provided with fixed leg 6,7,8,9 between upper substrate 1 and the infrabasal plate 2, the upper surface of described infrabasal plate 2 is provided with primary radiation unit 4, the upper surface of upper substrate 1 is provided with parasitic annulus chip unit 3, and the bottom surface of infrabasal plate 2 is provided with floor 10.Be provided with excitation port 5 between described primary radiation unit 4 and the floor 10.Fixed leg 6,7,8,9 can adopt insulation pillar or metal pillar.
Primary radiation unit 4 is made up of with a pair of rectangle outward flange projection 4-1 that is positioned on the circular patch diameter a circular patch.Described outward flange projection 4-1 is 45 ° with the angle that excitation port 5 becomes in the place, the center of circle of circular patch.
Described primary radiation unit 4 be shaped as in circle, ellipse, rectangle or the triangle any one.But in actual applications, as long as can produce the radiance of circular polarization.Outward flange projection 4-1 also can change into and cave inward, corner cut or add perturbation resistance etc. on paster, also can reach effect same.
The girth of described parasitic annulus chip unit 3 is greater than two wavelength.When its length during less than two wavelength, induced signal on the parasitic annulus chip unit 3 is " capacitive ", and the phase place of radiated electromagnetic wave is ahead of the primary radiation paster 4 of below, so parasitic annulus chip unit 3 is as sender, play the increase on-axis gain, reduce the effect of back lobe.When its length is slightly larger than two wavelength, induced signal is " perception " on the annulus paster of parasitic annulus chip unit 3, the phase place of radiated electromagnetic wave lags behind the primary radiation unit 4 of below, so parasitic annulus chip unit 3 is as antenna reflector, play the inhibition on-axis gain, increase the effect of low elevation angle place's gain.
The vertical range of upper substrate 1 and infrabasal plate 2 should not be too big, otherwise whole section is higher, recommends less than half wavelength.The vertical range that diameter by regulating parasitic annulus chip unit 3 annulus pasters and upper substrate 1 and infrabasal plate are 2, the control antenna antenna pattern is realized the optimum efficiency that will reach easily.
Described primary radiation unit 4, parasitic annulus chip unit 3 and floor 10 all can combine with upper substrate 1 and infrabasal plate 2 by the mode of printing.
Primary radiation unit 4 is mainly in order to produce the circular polarization radiation characteristic.For traditional circular polarization microstrip antenna, vertical plane 3dB lobe width generally between 70 ° to 90 °, further be widened the comparison difficulty to going in fact.And, mainly be devoted to how to widen the impedance bandwidth and the axial ratio bandwidth of antenna in existing flat circle poliarizing antenna design, almost do not consider the vertical plane lobe width that how to increase antenna.Antenna among the present invention by introducing annulus paster parasitic element 3, can be widened the vertical plane lobe width of antenna effectively on the basis of traditional planar microstrip paster structure.The hemisphere characteristic that traditional micro-strip paster antenna has zenith signal maximum and reduces gradually to horizontal plane, and the wheel the form of the foetus characteristic that the annulus paster antenna has zenith signal minimum and increases gradually to horizontal plane, therefore pass through the directional diagram of stack annulus paster antenna, can reduce the zenith signal of conventional microsthp patch antennas, increase near the low elevation gain of horizontal plane, thereby widen the lobe width of vertical plane effectively.
The structure that the present invention proposes in that the low section characteristic of antenna is influenced under the less situation, is widened the vertical plane lobe width of antenna significantly.Because parasitic annulus chip unit 3 has good symmetry, and be positioned at primary radiation unit 4 directly over, the energy that is coupled can be evenly distributed on the annulus of parasitic annulus chip unit 3 like this, and therefore the far-field pattern after the stack can keep original good omnidirectional's characteristic.
Diameter and distance upper substrate 1, infrabasal plate 2 between the effectively vertical plane lobe width of control antenna of the present invention by regulating parasitic annulus chip unit 3.
In order to illustrate that better the present invention, Fig. 4 have provided the dextrorotation gain curve that loads parasitic annulus chip unit 3 front and back antennas.
As mentioned above, just can realize the present invention preferably.
Embodiments of the present invention are not restricted to the described embodiments; other are any not to deviate from change, the modification done under spirit of the present invention and the principle, substitute, combination, simplify; all should be the substitute mode of equivalence, be included within protection scope of the present invention.