The coupled antenna of the special transformer terminals wireless public network communication automation system test of a kind of pair of epi-position
Technical field
The utility model belongs to power domain, relates to test antenna, the coupled antenna of the especially special transformer terminals wireless public network communication automation system test of a kind of pair of epi-position.
Background technology
Now, radio network technique obtains developing more and more widely, and radio network technique the most popular is at present no more than long distance radio network technique and near radio network technology.In view of the flourish and wide application prospect of short-distance radio network technical industry, for realizing seamless online and improving communication quality, dual polarized antenna is popular gradually in recent years, mainly it can provide polarization variation to its reason, to reduce the multipath fading of Received signal strength, channeling can double the capacity of wireless communication system, and the port that pair of orthogonal can be polarized is used separately as receiving terminal and transmitting terminal, realizes duplex operation.When being operated in transmission duplex pattern, dual polarized antenna is launched simultaneously or is received the electromagnetic wave of two orthogonal polarizations, and thus requiring two kinds to polarize between port has good isolation.Isolation between antennas refers to an antenna transmission signal, the signal received by another antenna and this ratio transmitted, and improves isolation between antennas and has become the problem often run in many wireless system antennas, usually requires that isolation between antennas is below-28dB.
In addition, design one is applied to small-power, the short-distance wireless transceiver of radio-frequency recognition system, Antenna Design is pith wherein.Good antenna system can make communication distance reach optimum state, and the kind of antenna is a lot, and different application needs different antennas.In small-power, short-range rfid system, need reliable communications, a cheap antenna system, coupling coil ring Shape antenna is the one relatively commonly used.
By the retrieval of patent document, not yet find the patent documentation identical with the utility model application.
Utility model content
The purpose of this utility model is to overcome the deficiencies in the prior art, a kind of coupled antenna that effectively can improve the special transformer terminals wireless public network communication automation system test of two epi-positions of isolation between antennas is provided, this antenna belongs to the high isolation dual polarized aperture-coupled antenna in 470-510MHz frequency range, is applicable to short-distance wireless array antenna unit.
The purpose of this utility model is achieved through the following technical solutions:
The coupled antenna of the special transformer terminals wireless public network communication automation system test of a kind of pair of epi-position, comprise grounding disc, radiation patch, air dielectric layer and feed substrate, microstrip feed line, it is characterized in that: on grounding disc, be shaped with a concentric boxes coupling slot, between this concentric boxes coupling slot groove, gap is identical, a radiation patch is being fixedly mounted with to should plane cover the grounding disc of concentric boxes coupling slot, this radiation patch adopts circular patch, is fixedly mounted with the air dielectric layer of between radiation patch and grounding disc; Be fixedly mounted with a FR4 feed substrate at the bottom surface of grounding disc, the axis position along radiation patch below feed substrate is fixedly mounted with a microstrip feed line.
And the groove width of described concentric boxes coupling slot from outer to inner progressively reduces, its ratio is 3:2:1.
And described microstrip feed line is connected to the radial direction of concentric boxes coupling slot, its open end is 6 millimeters to the distance of central point.
Advantage of the present utility model and good effect are:
1, this antenna have employed the feeding classification of evolved password to realize wide band characteristic, and compared to coaxial line or feed microstrip line, aperture-coupled has some significant advantages: feed place is without the need to solder joint, and the adjustable parameter for impedance matching is many; The substrate that feed structure and radiation patch adopt is separated from one another, and different dielectric materials and dielectric thickness can be selected independently to meet the needs of feed structure to radiation patch; By the adjustment coupling length in gap or the length of microstrip feed line open end, more easily impedance matching etc. can be reached with radiation patch than other feeding classifications, this antenna is exactly the feature utilizing the substrate of its feed structure and radiation patch separated from one another, adopt lower, that thickness the is larger radiation substrate of dielectric constant to reduce the Q value of antenna, thus reach the object of Bandwidth.
2, the ground plate of this Antenna Design can also shield the parasitic radiation of self-feed line, avoids its antenna pattern to antenna the first half to produce interference.
Accompanying drawing explanation
Fig. 1 is structural front view of the present utility model;
Fig. 2 is that the A-A of Fig. 1 is to cross-sectional view;
Fig. 3 is the structural representation removing radiation patch and dielectric layer of Fig. 1;
Fig. 4 is the rearview of Fig. 1.
Embodiment
Below in conjunction with accompanying drawing, embodiment of the present utility model is further described; The present embodiment is descriptive, is not determinate, can not limit protection range of the present utility model thus.
A coupled antenna for the special transformer terminals wireless public network communication automation system test of pair epi-position, this antenna is a kind of transducer, during transmitting, the high-frequency current of transmitter is converted into spatial electromagnetic ripple; During reception, the electromagnetic wave intercepted and captured is converted to high-frequency current sends into receiver from space.Its structure is as follows:
Grounding disc 1 is shaped with concentric boxes coupling slot 5, a radiation patch 3 is being fixedly mounted with to should plane cover the grounding disc of concentric boxes coupling slot, this radiation patch adopts circular patch, its radius R=12.8 millimeter, are fixedly mounted with the air dielectric layer 2 that a thickness is 2 millimeters between radiation patch and grounding disc; The FR4 feed substrate 6 that a dielectric constant is 4.4, thickness is 1mm is fixedly mounted with at the bottom surface of grounding disc, a microstrip feed line 4 is fixedly mounted with along the axis position of radiation patch below feed substrate, the width of this microstrip feed line is 2mm, to ensure that the input impedance of feeder line is 50 ohms.
In practical application, consider the aspects such as the firmness of antenna structure and impact resistance, air dielectric layer can be considered to adopt the materials such as the close foam of dielectric constant to fill; Between the groove of the concentric boxes coupling slot that grounding disc is made, gap is equal, but its groove width from outer to inner progressively reduces, and its ratio is 3:2:1.
Microstrip feed line is connected to the radial direction of concentric boxes coupling slot, and its open end is 6 millimeters to the distance of central point, to ensure that the input impedance of microstrip antenna obtains good coupling.
Description of Related Art of the present utility model is as follows:
A) selection of antenna substrate medium:
According to Cavity theory, radiation patch antenna can be equivalent to a leaky wave resonant cavity, although there is stronger radiation, it is still the resonator system that quality factor q value is higher.In order to effectively reduce the quality factor q value of microstrip antenna, the medium that dielectric constant is lower, thickness is thicker must be selected, and for feed substrate, thinner substrate is selected will effectively to reduce the spurious radiation carrying out self-feed line, in this example, owing to have employed aperture-coupled mode, therefore can select respectively for different needs.But the dielectric thickness of radiation substrate can not be too thick, otherwise easily play unnecessary higher mode and spurious radiation at paster antenna surface actuator, its maximum can not more than 0.052 λ usually.
B) selection of coupling slot groove width:
The impact of width on entire physical performance in coupling gap is less, and its value can be used for regulating the impedance matching of antenna.Usually, when increasing the thickness of aerial radiation substrate, also need the width strengthening gap to strengthen the degree of coupling.Antenna is insensitive to the change of its numerical value, generally makes it be less than 1/10th of gap length.Therefore, in the middle of application, specifically can select according to actual conditions.As in the middle of this antenna, the width progressively reducing gap can reach better matching result, but considers the convenience of actual fabrication, is just decided to be 1mm.
C) selection of feeder line open end length:
Both feeder line open end was to the distance of central point for the length of feeder line open end, and its value is commonly used to the reactance regulating aperture-coupled antenna, and in order to paster antenna and feeder line can reach optimized impedance matching, its value is typically chosen in quarter-wave.Meanwhile, its numerical value change also can cause the slight change of antenna resonant frequency, therefore in the middle of the design process of antenna, also can consider, and under the prerequisite ensureing impedance matching, utilizes it to finely tune the frequency of antenna.