Signal output device of metamaterial radiation source
Technical Field
The invention relates to the field of vacuum electronic devices, in particular to a signal output device of a metamaterial radiation source.
Background
In recent years, with experimental verification of a physical mechanism of a metamaterial radiation source, namely reverse cerenkov radiation, a novel device of the metamaterial radiation source gradually becomes a research hotspot in the field of vacuum electronics. The sub-wavelength characteristic of the metamaterial enables the metamaterial to have the characteristic of miniaturization; the high coupling impedance characteristic of the metamaterial enables the metamaterial to have the advantage of high power.
In the fields of airborne radar, deep space exploration, interplanetary link communication and the like, people expect that a microwave source has the characteristic of high power, and can ensure the detection distance of the radar and the transmission distance of communication signals; it is also desirable that the microwave source possess a smaller volume and lighter weight in order to be more easily integrated with the microwave power module and to ensure lower emission and operating costs. The former is typically represented by a vacuum microwave source, but it is bulky; the latter are typically represented by solid state microwave sources, but do not have high power characteristics.
Disclosure of Invention
Aiming at the defects in the prior art, the signal output device of the metamaterial radiation source provided by the invention has the characteristics of miniaturization and high power.
In order to achieve the purpose of the invention, the invention adopts the technical scheme that:
the signal output device of the metamaterial radiation source comprises a coaxial interface, a metamaterial transition structure, a square waveguide and a plurality of metamaterial resonance units; the square waveguide is a prism with a cavity, and two mounting holes for inserting the coaxial interfaces are formed in the side face of the square waveguide in the same length direction; each metamaterial transition structure is respectively connected with the coaxial interface and the metamaterial resonance unit; the metamaterial transition structure and the metamaterial resonant unit are both positioned in the cavity of the square waveguide.
The metamaterial transition structure comprises a matching compensation structure and a metamaterial resonance unit; the matching compensation structure is a strip-shaped cylinder, the coaxial interface is fixedly connected with the side face of the matching compensation structure, the matching compensation structure is fixed on the surface of the metamaterial resonance unit, and a rectangular hole is formed in the bottom surface of the prism of the square waveguide.
According to the microwave theory, the unobstructed transmission of signals between two ports requires that the impedance between the two ports is kept consistent or the impedance matching theory is satisfied. In the scheme, the impedance of the coaxial interface is inconsistent with the impedance of the metamaterial, so that the scheme is based on the impedance matching theory, the metamaterial transition structure is arranged between the coaxial interface and the metamaterial resonance unit, and good matching between the two coaxial interfaces is realized.
The invention has the beneficial effects that: the electron beam enters the cavity in the square waveguide through the rectangular hole and interacts with the metamaterial resonance units to generate a high-power signal, and the metamaterial transition structure and the special structure of the metamaterial resonance units can enable the signal to be transmitted smoothly in the device.
Further, the coaxial interface comprises a coaxial connector and a coaxial inner diameter probe; the coaxial connector is a hollow pipe; the length of the coaxial inner diameter probe is greater than that of the coaxial connector, and the diameter of the coaxial inner diameter probe is smaller than that of the inner circle of the coaxial connector; and a coaxial medium is arranged between the inner part of the coaxial connector and the coaxial inner diameter probe.
The coaxial interface close to the rectangular hole is mainly used for outputting high-power signals, and the coaxial interface far away from the rectangular hole is mainly used for observing reflected signals. Compared with a standard rectangular waveguide, the coaxial waveguide has the advantage of small size, and the coaxial waveguide has small radiation loss during signal transmission, so that the signal transmission quality is further improved.
Further, the metamaterial resonance unit is of a hollow structure in a shape of a "height of the face". The metamaterial resonance units and the matching compensation structure are integrally formed by a strip-shaped plate.
Furthermore, a groove for the coaxial inner diameter probe is arranged on the side surface of the matching compensation structure. The cross section of the cavity in the square waveguide is provided with a clamping groove for fixing a plurality of metamaterial resonance units. The length and width of the internal section of the square waveguide are 1/10-1/5 of the working wave length lambda of the electromagnetic wave.
For signals with the frequency between 2.7GHz and 3.3GHz, the square waveguide cannot independently transmit signals in the frequency range without arranging the metamaterial resonance unit inside the square waveguide.
Drawings
FIG. 1 is a side cross-sectional view of the present invention;
FIG. 2 is a top view of the present invention with the square waveguide removed;
FIG. 3 is a dimension marked diagram of a top view of a metamaterial resonance unit according to the invention;
FIG. 4 is an isometric view of the invention with the square waveguide removed;
FIG. 5 is a graph of results obtained in simulation software according to the present invention;
in the figure: 100-coaxial interface, 101-coaxial connector, 102-coaxial inner diameter probe, 201-matching compensation structure, 202-metamaterial resonance unit and 301-square waveguide.
Detailed Description
The following description of the embodiments of the present invention is provided to facilitate the understanding of the present invention by those skilled in the art, but it should be understood that the present invention is not limited to the scope of the embodiments, and it will be apparent to those skilled in the art that various changes may be made without departing from the spirit and scope of the invention as defined and defined in the appended claims, and all matters produced by the invention using the inventive concept are protected.
As shown in fig. 1 and 4, the present solution provides a signal output device of a metamaterial radiation source, which includes a coaxial interface, a metamaterial transition structure, a square waveguide 301, and a plurality of metamaterial resonance units 202; the square waveguide 301 is a prism with a cavity, and two mounting holes for inserting coaxial interfaces are formed in the side face of the square waveguide in the same length direction; each metamaterial transition structure is respectively connected with the coaxial interface and the metamaterial resonance unit 202; the metamaterial transition structure and the metamaterial resonant unit 202 are both located inside the cavity of the square waveguide 301.
In the present embodiment, the metamaterial transition structure includes a matching compensation structure 201 and a metamaterial resonance unit 202; the matching compensation structure 201 is a strip-shaped column, the coaxial interface is fixedly connected with the side face of the matching compensation structure 201, and the matching compensation structure 201 is fixed on the surface of the metamaterial resonance unit 202. The prism bottom surface of the square waveguide 301 is provided with a rectangular hole.
According to the microwave theory, the unobstructed transmission of signals between two ports requires that the impedance between the two ports is kept consistent or the impedance matching theory is satisfied. In the invention, the impedance of the coaxial output port is not consistent with that of the metamaterial, so that the metamaterial transition structure is designed based on the impedance matching theory, and the metamaterial transition structure is arranged between the coaxial interface and the metamaterial resonance unit, thereby realizing good matching between the two coaxial interfaces.
The electron beam enters the cavity inside the square waveguide 301 through the rectangular hole, interacts with the metamaterial resonance units 202 and is converted into a high-power signal, and the metamaterial transition structure and the special structure of the metamaterial resonance units 202 enable the signal to be transmitted smoothly inside the device.
As shown in fig. 1, in the present embodiment, the coaxial interface includes a coaxial connector 101 and a coaxial inner diameter probe 102; the coaxial connector 101 is a hollow tube; the length of the coaxial inner diameter probe 102 is 6.65mm more than the length of the coaxial connector 101, the diameter of the coaxial inner diameter probe 102 is 1.2mm, and the diameter of the inner circle of the coaxial connector 101 is 4.2 mm. Wherein the number of coaxial interfaces is two. A coaxial medium is also provided between the inside of the coaxial connector 101 and the coaxial inner diameter probe 102.
The coaxial interface close to the rectangular hole is mainly used for outputting high-power signals, and the coaxial interface far away from the rectangular hole is mainly used for observing reflected signals. Compared with a standard rectangular waveguide, the coaxial waveguide has the advantage of small size, and the coaxial waveguide has small radiation loss during signal transmission, so that the signal transmission quality is further improved.
As shown in fig. 2 and 3, the metamaterial resonant unit 202 has a hollowed-out structure having a shape of "height". The metamaterial resonant units 202 and the matching compensation structure 201 are integrally machined and formed by a strip-shaped copper plate. Each partial size of the metamaterial resonant unit 202 is preferably designed to be w equal to 1.5mm, a equal to 14.5mm, d equal to 1mm, h1 equal to 4.25mm, h2 equal to 4mm, g equal to 1mm, j equal to 1.5mm, and f equal to 0.5 mm. Wherein w is the width of the metamaterial transition structure; a is the length and width of the "king" shaped plate of the "national" shaped plate; b is a space between two bilaterally symmetrical portions of the "national" shaped plate; h1 is the length of the king-shaped plate at the upper and lower horizontal positions; h2 is the width of the king-shaped plate at the upper and lower horizontal positions; g is the distance from the plate represented by the vertical stroke of the king-shaped plate to the middle hollow area; j is the width of the plate represented by a cross in the middle of the king-shaped plate; f is the width of the edge "mouth" shaped plate.
In this embodiment, the matching compensation structure 201 is flanked by grooves for the coaxial id probe 102. The side of the cavity inside the square waveguide 301 is provided with a slot for fixing a plurality of metamaterial resonant units 202. The length and width of the inner cross section of the square waveguide 301 are 1/10-1/5 of the operating wave length λ of the electromagnetic wave.
For signals with frequencies between 2.7GHz-3.3GHz, the square waveguide 301 cannot independently transmit signals within the above frequency range without providing a metamaterial resonance unit inside the square waveguide 301.
As shown in fig. 3 and 5, in the present embodiment, the metamaterial resonant unit 202 is configured such that w is 1.5mm, t is 1.2mm, a is 14.5mm, b is 13.5mm, d is 1mm, h1 is 4.25mm, h2 is 4mm, g is 1mm, j is 1.5mm, and f is 0.5mm, and the simulation result of the simulation experiment performed by the metamaterial resonant unit 202 based on this configuration is shown in fig. 5, where S1, 1 represents a reflected signal curve and S2, 1 represents an output signal curve.
According to simulation results, the reflection coefficient is-10 to-17 decibels in a frequency band of 2.85GHz-3.1GHz under the working condition of normal temperature and pressure; the transmission coefficient is-0.5 to-1 decibel, and a curve can show that the signal output device has very small reflection and very good transmission characteristic, and the generated signals can be completely and effectively transmitted.
In summary, the sizes appearing in this embodiment are the optimal sizes of the present solution, and the present solution combines the special structure of the special metamaterial resonant unit 202 and the advantages of the coaxial interface, thereby achieving the purposes of high power output and miniaturization.