Pocket super-broadband antenna
Technical field
What the present invention relates to is a kind of antenna that is used for wireless communication technology field, especially a kind of pocket super-broadband antenna.
Background technology
In recent years, ultra broadband (UWB) short-distance wireless communication had caused that the global communication technical field paid attention to greatly.Ultra-wideband Communication Technology is strong with its transmission rate height, anti-multipath interference performance, high security, help advantage such as multifunctional all and become short-distance wireless communication and have one of technology of competitiveness and development prospect.After in February, 2002, FCC used the no licence of issue to use to ultra broadband, super-broadband tech became a focus of international wireless communications field research and development rapidly, and is regarded as one of key technology of next generation wireless communication.Propose to distribute the needs of 3.1~10.6GHz frequency range to the ultra-wideband communications use at the IEEE802.15.3a standard, super Wide antenna becomes one of research focus.The ultra-wideband antenna structure that some are classical, as traveling-wave antenna, logarithm periodic antenna, equiangular spiral antenna, ridge waveguide horn antenna etc., these antenna can be realized the working band of several octaves, can cover 3.1~10.6GHz working frequency range fully.But these classical ultra-wideband antenna structures all have a common shortcoming, and are promptly many greatly than the physical dimension of narrow-band antenna of the same type, do not satisfy the little requirement of UWB system configuration.Therefore, the research that is used for the miniature ultra wide band Antenna Design of UWB system still is a focus of antenna Recent study.
Find through literature search prior art, number of patent application 200510130662.1, patent name is: micro band superwide band antenna, patent publication No. CN 1787286, the signal metal of this ultra-wideband antenna and ground level metal are printed on the tow sides of pcb board respectively, and the major part of antenna is made up of a wine glass-shaped signal metal and two blocks of ground level metals.Though this antenna can satisfy transmitting and receiving to cover 3.1~10.6GHz working frequency range of ultra-wideband impulse signal.But the resonance point skewness of the frequency characteristic of this antenna be difficult for to be realized linear phase, and the impedance matching that needs size by changing the wine glass-shaped metal and feed angle to realize antenna in design is unfavorable for the miniaturization Design of antenna.
Find also in the retrieval that people such as Zhi Ning Cheng have proposed antisymmetric Vivaldi (Wei Waer Supreme Being) antenna in European electromagnetism meeting in 2004 and Asia-Pacific microwave meeting (APMC2005), this antenna designs obverse and reverse at medium respectively with little band radiating element of two gradual changes of two Vivaldi antennas, simultaneously in the increase of the microstrip element of feed the gradual change feeder line of two semicircles.This antenna has the characteristic of broadband impedance conversion, can effectively cover 3.1~10.6GHz working frequency range.But owing to will adopt the exponential line and the little realization broadband character that brings of semicircle of gradual change, therefore make that the size of antenna is bigger, be unfavorable for the miniaturization Design of antenna.
Summary of the invention
The objective of the invention is to overcome the deficiencies in the prior art and defective, a kind of pocket super-broadband antenna is provided, make it can realize utilizing single microband paste to realize that IEEE 802.15.3a standard proposes the requirement of 3.1~10.6GHz frequency range, simultaneously this micro band superwide band antenna have that volume is less relatively, structure simple and clear, easy conformal advantage.
The present invention is achieved by the following technical solutions, the present invention includes: input output port, microstrip-fed unit, microband antenna unit, dielectric-slab and ground unit.Microband antenna unit and the microstrip-fed unit non-uniform microstrip line paster for calculating according to the back scattering method is positioned at the front of dielectric-slab, input the core and the microstrip-fed unit of output port join, ground unit is the part that is positioned at the dielectric-slab back side.
Described microband antenna unit and microstrip-fed unit are positioned at the dielectric-slab front, and the physical dimension of entire antenna is calculated according to improved Z-S back scattering method, is non-uniform Distribution.
Described microband antenna unit and microstrip-fed unit are equated by electrical length on the whole and non-homogeneous microband paste cascade that width does not wait forms, and its overall electrical length is to be 0.2 times of wavelength of benchmark with 1GHz.
Described microband antenna unit, microstrip-fed unit and ground unit are conductor, ground unit and input the outer conductor of output port be connected.
Described dielectric-slab is the low-k material.
The present invention compares with existing invention: the design of existing ultra-wideband antenna mainly all is a forward mentality of designing, promptly realize the characteristic of ultrabroad band by known structure, specifically need realize the impedance matching of antenna by the physical dimension of adjusting antenna, improve directional diagram and gain.The main limitation of such method for designing is to have randomness and contingency sometimes in the design, and may be more time-consuming.And the bright advantage of we to be to design be a reverse mentality of designing process, by needed index request is that frequency characteristic is set out, by finding the solution inverse problem, solve the distribution of impedance of the antenna that can realize this frequency characteristic, and then solve the geometric distributions of this antenna.The advantage of such method for designing has with clearly defined objective fast with desin speed when being designing antenna.And in design process since used be improved inverse scattering algorithm but not general business software can constantly pass through the optimization aim function, the miniaturization of realization antenna.Its overall electrical length of pocket super-broadband antenna of the present invention is to be 0.2 times of wavelength of benchmark with 1GHz, and the standing-wave ratio in designed frequency band is less than 2, and the resonance point of frequency characteristic is evenly distributed, and can realize the linear phase in the ultra-wideband communications.
The non-homogeneous micro-strip paster antenna that the present invention utilizes inverse scattering method to design has less relatively size, and structure is simple and clear, it is conformal to be easy to, and has covered the frequency requirement of FCC, the i.e. band bandwidth of 3.1~10.6GHz effectively.
Description of drawings
Fig. 1 is the three-dimensional structure schematic diagram of a kind of pocket super-broadband antenna of the present invention
Fig. 2 is the Facad structure schematic diagram of a kind of pocket super-broadband antenna of the present invention
Fig. 3 is the side-looking structural representation of a kind of pocket super-broadband antenna of the present invention
Fig. 4 is the reverse side structural representation of a kind of pocket super-broadband antenna of the present invention
Fig. 5 is the frequency characteristic figure of a kind of pocket super-broadband antenna emulation of the present invention
Embodiment
Below in conjunction with accompanying drawing embodiments of the invention are elaborated: present embodiment is being to implement under the prerequisite with the technical solution of the present invention, provided detailed execution mode and concrete operating process, but protection scope of the present invention is not limited to following embodiment.
As shown in Figure 1, present embodiment comprises: input output port 1, microstrip-fed unit 2, microband antenna unit 4, dielectric-slab 3 and ground unit 5.Microband antenna unit 4 and microstrip-fed unit 2 non-uniform microstrip line paster for calculating according to the back scattering method, be positioned at the front of dielectric-slab 3, input the core and the microstrip-fed unit 2 of output port 1 join, ground unit 5 is the parts that are positioned at the dielectric-slab back side.
Described microband antenna unit 4 and microstrip-fed unit 2 are positioned at the front of dielectric-slab 3, and the physical dimension of entire antenna is calculated according to improved Z-S back scattering method, is non-uniform Distribution.Be specially: calculate the forward wave of non-uniform microstrip line and the coupling coefficient of backward-wave by finding the solution Xue Ding Hubei Province equation and Zakharov-Shabat equation group according to required frequency bandwidth (3.1GHz-10.6GHz), solve the distribution of impedance function of little band according to coupling coefficient, and then solve the physical dimension distribution of non-homogeneous microstrip antenna.
Described microband antenna unit 4 and microstrip-fed unit 2 are equated by electrical length on the whole and non-homogeneous microband paste cascade that width does not wait forms, and its overall electrical length is to be 0.2 times of wavelength of benchmark with 1GHz.
Described microband antenna unit 4, microstrip-fed unit 2 and ground unit 5 are conductor, ground unit 5 and input the outer conductor of output port 1 be connected.
Described dielectric-slab 3 is the low-k material.
As shown in Figure 5, the frequency characteristic of present embodiment is a return wave loss parameter.Wherein abscissa is represented frequency variable, and unit is GHz; Ordinate is represented the amplitude variable, and unit is dB.The working band of a kind of pocket super-broadband antenna of present embodiment is 2.8GHz-11.0GHz, return wave loss parameter in passband less than-12dB.
The course of work of present embodiment is: described input output port 1 outer signal source, the pumping signal that adds is transferred to microband antenna unit 4 by microstrip-fed unit 2, go out by microband antenna unit 4 space radiation towards periphery then, realize the function of radio communication.