CN102456947A - Single-layer circularly symmetric GPS-BD (Global Position System-Big Dipper) dual-frequency microstrip antenna - Google Patents

Abstract

The invention belongs to a dual-frequency microstrip antenna, particularly relates to a circularly symmetric GPS-BD (Global Position System-Big Dipper) dual-frequency circular polarization microstrip antenna manufactured by using a single-layer dielectric slab. The circularly symmetric GPS-BD dual-frequency circular polarization microstrip antenna comprises a dielectric substrate, wherein the central original point of the dielectric substrate is provided with a central circular radiating element; the outer sides of the central circular radiating element are symmetrically provided with spiral radiating elements on which feeding probes are arranged; and the dielectric substrate is fixedly connected to a metal earthing surface. The circularly symmetric GPS-BD dual-frequency circular polarization microstrip antenna has the advantages that the antenna has a single-layer circularly symmetric structure and is provided with a circular patch unit at the inner side and a spiral unit at the outer side. Due to the structure, the excellent characteristics of wide-angle circular polarization and zero phase difference are achieved, and meanwhile, the antenna has the characteristics of low section, simplicity and convenience in processing and manufacturing and the like.

Description

The symmetrical GPS-BD double-frequency micro-strip antenna of a kind of individual layer circle

Technical field

The invention belongs to a kind of double frequency-band microstrip antenna, be specifically related to a kind of symmetrical GPS-BD double frequency-band of circle circular polarization microstrip antenna that is made by the single-layer medium plate.

Background technology

Along with the effect more and more significant that Technique of Satellite Navigation and Positioning plays in military-civil field, people are increasingly high to the attention rate of satellite navigation and location system, and are also increasingly high to the requirement of satellite navigation.High accuracy, high stability all are the developing direction of satellite navigation.The satellite navigation system of having used at present has GPS of USA, and Muscovite GLONASS also has Chinese dipper system.The compatible receiver of multisystem aspect calculation accuracy and the reliability all tool have great advantage, in the high accuracy time service was used, the dipper system of use China independent development had higher fail safe, has broken away from the dependence fully to GPS simultaneously.The systemic breakdown that causes because of not time service of GPS once appearred in the cdma network of China in history.So multisystem is integrated is later satellite positioning navigation Equipment of Development trend, and antenna also is faced with the compatible problem of multisystem as the important component part of satellite navigation, just multiband aerial.

Because the microstrip antenna volume is little, in light weight, section is low and be easy to processing and fabricating, and the ten minutes of in the satellite navigation receiving system, using at present is extensive, but that one of shortcoming of microstrip antenna is a relative bandwidth is narrower.For GPS, the receiving system that BD1 is compatible needs antenna on the signal frequency of these two systems, all will realize normal reception, and single microband antenna unit is difficult to realize that so big bandwidth receives the signal of GPS and these two frequencies of BD1 simultaneously.For satisfying this demand, existing GPS, the implementation of BD1 double frequency reception antenna mainly contains two kinds: one, with two antenna elements-GPS unit, BD1 places the unit side by side; Two, two antenna element laminations are placed; Method for designing like 200710099065.6 1 kinds of double frequency round polarized laminated micro band antenna of the patent No.; 200920045847.6 1 kinds of GPS of the patent No. and dual frequency active reception antenna of the Big Dipper, 200920013024.5 1 kinds of two-band receiving antennas of satellite navigation of the patent No. etc. are said.For first kind of scheme; Its modes of emplacement arranged side by side can influence characteristics such as antenna antenna pattern and axial ratio separately; Because GPS; The electromagnetic wave of BD1 system all is the mode of the right-handed circular polarization of employing, and it all is non-symmetrical structure that two antenna elements placing side by side can cause concerning each antenna element.The mode of placing side by side simultaneously also is unfavorable for the miniaturization of antenna.Dual-band antenna with respect to second kind of stacked system of modes of emplacement arranged side by side has avoided occurring the asymmetric situation of structure; But it still need make two independent antenna elements; And need both be combined through the mode of conductive adhesive; Need guarantee the relative position of the two in the bonding process, complex manufacturing process, and cost is high.

Summary of the invention

The purpose of this invention is to provide and a kind ofly can realize that excellent wide angle circular polarization differs characteristic with zero, have low section simultaneously, the symmetrical GPS-BD double-frequency micro-strip antenna of individual layer circle of characteristics such as processing and fabricating is simple and convenient.

The present invention realizes like this; The symmetrical GPS-BD double-frequency micro-strip antenna of a kind of individual layer circle; It comprises medium substrate, is provided with the central circular radiating element at the center origin place of medium substrate, and symmetry is provided with the spirality radiating element in the outside of central circular radiating element; The spirality radiating element is provided with feed probes, and medium substrate is fixedly connected on the metal ground plane.

Medium substrate is connected on the metal ground plane through screw.

Described spirality radiating element is four arm Archimedian screw shape radiating elements.

Advantage of the present invention is that this antenna adopts individual layer circle symmetrical structure, inner circular chip unit, spirality unit, the outside.Characteristics such as this structure has realized that excellent wide angle circular polarization differs characteristic with zero, has low section simultaneously, and processing and fabricating is simple and convenient.

Description of drawings

Fig. 1 is the symmetrical GPS-BD double-frequency micro-strip antenna sketch map of a kind of individual layer circle provided by the present invention;

Fig. 2 is a BD1 frequency gain pattern of the present invention;

Fig. 3 is the axial ratio directional diagram of BD1 frequency of the present invention;

Fig. 4 is the gain pattern of GPS frequency of the present invention;

Fig. 5 is the axial ratio directional diagram of GPS frequency of the present invention.

Among the figure, 1 medium substrate, 2 circular radiating elements, 3 spirality radiating elements, 4 feed probes, 5 mounting screw holes.

Embodiment

Describe the present invention below in conjunction with accompanying drawing and embodiment:

As shown in Figure 1; The symmetrical GPS-BD double-frequency micro-strip antenna of a kind of individual layer circle; It comprises circular microwave-medium substrate 3, at the center origin place of microwave-medium substrate 3 central circular radiating element 4 is installed, and symmetry is equipped with four arm Archimedian screw shape radiating elements 1 in the outside of central circular radiating element 4; On two spirality radiating elements 1 feed probes 5 is installed therein, wherein microwave-medium substrate 3 also is installed on the metal ground plane through 4 mounting screws 2.

Wherein, spirality radiating element 1 and the copper clad patterns of circular radiating element 4 on the microwave-medium substrate, processing.Feed probes 5 is columniform copper metallic conductor.

Principle of the present invention is that double-frequency micro-strip antenna adopts two to be positioned at the resonant element on one deck medium and to realize; Symmetry for the structure that guarantees two antenna elements; The form that realizes can only be that a resonant element is positioned at the center, and another resonant element is positioned at the outside and the assurance center symmetry of center cell.Because the frequency of BD1 is higher, the position of the unit so BD1 all shakes (BD1 all shake unit refer to center original shape radiating element) centering can make final antenna volume minimize like this.The BD1 radiating element adopts the form of single-point feedback.The GPS resonant element refers to four arm Archimedian screw shape radiating elements.

Can calculate the initial designs size of antenna by following formula, and the dielectric constant of the required microwave-medium substrate of preparation antenna.

$r=\frac{K}{{\{1+\frac{2h}{{\mathrm{\π\ϵ}}_{r}K}[\ln \left(\frac{\mathrm{\πK}}{2h}\right)+1.7726\left]\right\}}^{1/2}}$

In the formula,

H is a substrate thickness, and f is an operating frequency, and r is the radius of radiating element, ε _rRelative dielectric constant for the microwave-medium substrate.Initial design size is carried out modeling and simulating to this paster antenna after confirming in Electromagnetic Simulation software, with the accurate dimension of definite antenna radiation pattern, and the position of distributing point etc.

The gps antenna radiating element adopts the form of little band spiral arm; This unit comprises the spirality radiating pattern that 4 strips are identical altogether; And these 4 figures are that central shaft is symmetrically distributed with the center of BD1 antenna element figure, and adjacent two spirality radiating patterns are identical with respect to the anglec of rotation at center arbitrarily.The inside and outside curve of spirality radiating pattern adopts Archimedian screw to define:

X _n＝A _n×exp(α _igθ)×cos(θ)

Y _n＝-A _n×exp(α _igθ)×sin(θ)

0≤θ≤N×2π

Wherein, A _nBe the coordinate figure of the central point of helical curve, α _i, α _jBe the rotation proportionality constant of helical curve, N is the rotating cycle of helical curve.

The internal diameter of Archimedian screw is A just _nValue need confirm according to the size dimension of BD1 antenna element, the length of spiral arm, promptly rotating cycle N confirms through operating frequency.The Archimedian screw unit adopts the feeding classification of double-fed point phase shift 90 degree to form circular polarization among the present invention, only selects two alternate arm feeds in four spiral arm, and that has avoided that four arm feed use simultaneously Ba Lun bring is numerous and diverse.

Antenna making process of the present invention is following:

(1) at first confirms the dielectric constant of the medium substrate of selecting for use, dielectric-slab thickness etc. according to designing requirement.Dielectric constant influences the size of radiating pattern, and the area of microband paste and the thickness of substrate have determined the operating frequency of antenna, and to circular patch of the present invention, its radius can be obtained by formula: in the formula, h is a substrate thickness, and f is an operating frequency.Through the following formula repeated calculation, confirm the kind of sheet material, obtain sizeable figure.

(2) rectangular groove is opened at the center of circular microstrip paster, adjusts the degree that degenerate mode separates through length and the width of adjusting rectangular groove and forms circular polarization at last.

(3) the suitable place punching of impedance is selected in the corresponding different character impedance in different position on the paster, is used for installing feed probes.

(4) confirm the internal diameter of external helicoid radiating element according to the size of existing center patch unit.

(5) the inside and outside curve of spiral arm is a spiral of Archimedes,

X _n＝A _n×exp(α _igθ)×cos(θ)

Y _n＝-A _n×exp(α _jgθ)×sin(θ)

0≤θ≤N×2π

Wherein, A _nBe the coordinate figure of the central point of helical curve, α _i, α _jBe the rotation proportionality constant of helical curve, N is the rotating cycle of helical curve.Adjust the width of spiral arm through the anglec of rotation of adjusting two curves.Adjustment A _nAnd α _i, α _jValue can adjust the autgmentability and the helicity of spiral arm.

(6) obtain the location point of the impedance matching on the spiral arm through simulation calculation,, be used to install feed probes,, select two wherein adjacent arm feeds to get final product because the figure of four spiral arm is identical in this place's punching.

Claims (3)

1. an individual layer is justified symmetrical GPS-BD double-frequency micro-strip antenna; It is characterized in that: it comprises medium substrate (3); Be provided with central circular radiating element (4) at the center origin place of medium substrate (3); In the outside of central circular radiating element (4) symmetry be provided with spirality radiating element (1), spirality radiating element (1) is provided with feed and visits true (5), medium substrate (3) is fixedly connected on the metal ground plane.

2. the symmetrical GPS-BD double-frequency micro-strip antenna of a kind of individual layer circle as claimed in claim 1, it is characterized in that: medium substrate (1) is fixedly connected on the metal ground plane through screw (2).

3. like claim 1 or the symmetrical GPS-BD double-frequency micro-strip antenna of 2 described a kind of individual layer circles, it is characterized in that: described spirality radiating element (1) is four arm Archimedian screw shape radiating elements

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