阅读说明：本技术 基于半切技术的频率可调谐微带贴片谐振器 (Frequency-tunable microstrip patch resonator based on half-cut technology ) 是由 陈建新 张小珂 王雪颖 唐世昌 杨玲玲 于 2020-12-04 设计创作，主要内容包括：本发明涉及一种基于半切技术的频率可调谐微带贴片谐振器,包括自下而上依次层叠设置的金属地、底层基板、顶层基板和微带贴片,底层基板和顶层基板之间具有一个频率调谐用微带线,频率调谐用微带线隔着顶层基板与微带贴片非接触地交叠,频率调谐用微带线外端与加载在顶层基板上表面的可变电容的内端电连接,可变电容外端与金属地电连接,微带贴片远离可变电容的一侧接地。频率调谐用微带线与可变电容构成非接触式频率调谐结构,用于连续的调谐谐振器的频率。本发明首次提出一种新型的非接触式可变电容加载方案,来设计工作在主模TM10下的频率可重构的微带贴片谐振器。(The invention relates to a frequency tunable microstrip patch resonator based on a half-cut technology, which comprises a metal ground, a bottom substrate, a top substrate and a microstrip patch, wherein the metal ground, the bottom substrate, the top substrate and the microstrip patch are sequentially stacked from bottom to top, a microstrip line for frequency tuning is arranged between the bottom substrate and the top substrate, the microstrip line for frequency tuning is overlapped with the microstrip patch in a non-contact way by separating the top substrate from the top substrate, the outer end of the microstrip line for frequency tuning is electrically connected with the inner end of a variable capacitor loaded on the upper surface of the top substrate, the outer end of the variable capacitor is electrically connected with the metal ground, and one side of. The microstrip line for frequency tuning and the variable capacitor form a non-contact frequency tuning structure for continuously tuning the frequency of the resonator. The invention firstly provides a novel non-contact variable capacitance loading scheme to design a frequency-reconfigurable microstrip patch resonator working under a main mode TM 10.)

1. The utility model provides a tunable microstrip patch resonator of frequency based on half cuts technique, includes metal ground (9), bottom base plate (8), top layer base plate (5) and microstrip patch (1) that stack gradually the setting from bottom to top, its characterized in that: the frequency tuning microstrip line (6) is arranged along the center line of the microstrip patch (1) between the bottom substrate (8) and the top substrate (5), the top substrate (5) is arranged between the frequency tuning microstrip line (6) and the microstrip patch (1), the frequency tuning microstrip line (6) and the microstrip patch (1) are projected on the bottom substrate (8) in an intersecting manner, the outer end of the frequency tuning microstrip line (6) is electrically connected with the first end of the variable capacitor (2) loaded on the upper surface of the top substrate (5), the second end of the variable capacitor (2) is electrically connected with the metal ground (9), one side of the microstrip patch (1) far away from the variable capacitor (2) is grounded, and the frequency tuning microstrip line (6) and the variable capacitor (2) form a non-contact frequency tuning structure.

2. A frequency tunable microstrip patch resonator according to claim 1, wherein: the outer end of the microstrip line (6) for frequency tuning is electrically connected with the first end of the variable capacitor (2) through a metalized through hole (4) penetrating through the top substrate (5).

3. A frequency tunable microstrip patch resonator according to claim 1, wherein: the second end of the variable capacitor (2) is electrically connected with the metal ground (9) through a metalized through hole (3) penetrating through the top substrate (5) and the bottom substrate (8).

4. A frequency tunable microstrip patch resonator according to claim 1, wherein: the inner end of the variable capacitor (2) is the first end, and the outer end of the variable capacitor (2) is the second end.

5. A frequency tunable microstrip patch resonator according to claim 1, wherein: one side of the microstrip patch (1), which is far away from the variable capacitor (2), is electrically connected through a metalized through hole (7) which penetrates through the top layer substrate (5) and the bottom layer substrate (8).

6. The frequency tunable microstrip patch resonator of claim 1, wherein: the microstrip patch (1) is a rectangular microstrip patch and is arranged in the center of the top substrate (5).

7. The frequency tunable microstrip patch resonator of claim 1, wherein: the variable capacitor (2) is arranged on the central line of the microstrip patch (1).

8. A frequency tunable microstrip patch resonator according to claim 1, wherein: the bottom substrate (8) is a double-sided printed circuit board, the top layer of the double-sided printed circuit board is the microstrip line (6) for frequency tuning, and the bottom layer of the double-sided printed circuit board is the metal ground (9).

Technical Field

The invention relates to the technical field of wireless communication, in particular to a frequency-tunable microstrip patch resonator based on a half-cut technology.

Background

As communication systems are miniaturized, more components need to be integrated into a limited space, and thus miniaturization technology of antennas has received much attention. The size of the antenna is closely related to its performance, and thus the design for a miniaturized antenna is not easy. The method for realizing miniaturization of the antenna can be as follows: (1) the original frequency of the antenna is maintained, and the physical size of the antenna is reduced. (2) The physical size of the antenna is kept unchanged, and the working frequency of the antenna is reduced, so that the effect of reducing the electrical size of the antenna is achieved. Miniaturization technologies for microstrip antennas are currently mainly based on the use of new materials or the design of new antenna structures. For example, a magneto-dielectric substrate with a compact structure is designed by using metamaterials, and the size of an antenna is reduced under the condition of unchanged frequency by increasing the parameters of the substrate; shorting one end of the microstrip patch can reduce the physical size of the antenna by half at certain frequencies.

In order to meet the development requirements of wireless communication systems, multifunctional antennas have been extensively studied in recent years. Among them, the excellent performance of the reconfigurable antenna becomes a research hotspot. The reconfigurable antenna has the excellent characteristics of small size, flexible function and the like, and can replace a plurality of antennas. The reconfigurable resonator is a core unit of the reconfigurable antenna, and directly influences the performance of the reconfigurable antenna. In recent years, various reconfigurable resonators have been designed, which are widely used in polarization reconfigurable, pattern reconfigurable, and frequency reconfigurable antennas. They play an important role in modern wireless communication systems. Of these, frequency reconfigurable resonators are of interest for use in cognitive radio systems that perform both sensing frequency and communication functions. Such resonators can be realized by loading tunable elements, for example, using pin diodes to switch between discrete states, or loading variable capacitances to continuously tune the operating state. In addition, reconfigurable performance can also be achieved using radio frequency micro-electromechanical systems (MEMS) or liquid metals.

The microstrip patch resonator has the advantages of low section, high gain, easy loading of variable capacitance and the like, so that the microstrip patch resonator is widely applied to reconfigurable resonators, particularly to the design of frequency reconfigurable resonators. Typically, the variable capacitance is loaded directly on the microstrip patch. In the document "Frequency-reconfigurable low-profile monolithic resonator antenna" (l. Ge and k. Luk, EEE Trans Antennas, pro pag., vol. 62, No. 7, pp. 3443-3449, July 2014), a Frequency-reconfigurable stacked patch resonator is proposed, the antenna consisting of two stacked square patches, each patch being divided into two rectangular sections by a gap, and a variable capacitor being loaded directly in the gap between the microstrip patches. The document "universal-side mounted patch antenna with independent frequency reconfiguration" (l. Ge, m. Li, j. Wang and h. Gu, IEEE Antennas Wireless performance testing, vol. 16, pp. 113-.

However, the tunable structure is directly connected with the radiation patch, so that the radiation performance of the resonator is greatly influenced by the variable capacitor, therefore, a novel non-contact variable capacitor loading scheme is firstly provided to design the frequency reconfigurable resonator working in a main mode TM10 mode.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a frequency-tunable microstrip patch resonator based on a half-cut technology.

In order to achieve the purpose of the invention, the frequency tunable microstrip patch resonator based on the half-cut technology comprises a metal ground, a bottom substrate, a top substrate and a microstrip patch which are sequentially stacked from bottom to top, and is characterized in that: the bottom substrate and the top substrate are provided with a frequency tuning microstrip line arranged along the central line of the microstrip patch in a half-cut mode, the top substrate is arranged between the frequency tuning microstrip line and the microstrip patch, the frequency tuning microstrip line and the microstrip patch are intersected in projection on the bottom substrate, the outer end of the frequency tuning microstrip line is electrically connected with the first end of a variable capacitor loaded on the upper surface of the top substrate, the second end of the variable capacitor is electrically connected with a metal ground, the frequency tuning microstrip line and the variable capacitor form a non-contact frequency tuning structure, and one side, away from the variable capacitor, of the microstrip patch is grounded.

The microstrip patch resonator comprises a microstrip patch and two layers of dielectric substrates, wherein the microstrip patch is placed on the top substrate, and one side of the microstrip patch is connected with a metal ground, so that half-cutting of the microstrip patch is realized. The resonator introduces a non-contact frequency tunable structure, the frequency tunable structure is composed of a non-contact frequency tuning microstrip line and a corresponding variable capacitor, the microstrip line and the microstrip patch are positioned in the middle layer, the microstrip line and the microstrip patch are projected and intersected on the bottom substrate and used for tuning the frequency of the microstrip patch resonator, and the variable capacitor is loaded at the tail end of the microstrip line for frequency tuning and used for realizing the continuous tuning of the frequency of the resonator. The top substrate is arranged between the microstrip line and the microstrip patch for non-contact frequency tuning, so that the influence of a loading tunable structure on the radiation performance of the resonator can be reduced when the microstrip line and the microstrip patch are actually applied to an antenna, and the design freedom is improved. The present resonator can be used for the base film TM10 mode.

Drawings

The invention will be further described with reference to the accompanying drawings;

figure 1 is a perspective view of a non-contact frequency tunable microstrip patch resonator of the present invention.

Figure 2 is a side view of a non-contact frequency tunable microstrip patch resonator of the present invention.

Fig. 3 is a schematic structural diagram of a non-contact frequency tunable microstrip patch resonator according to the present invention.

Fig. 4 is an equivalent circuit diagram of the tunable structure of the non-contact frequency tunable microstrip patch resonator of the present invention.

FIG. 5 shows the overlapping length of the microstrip line and the microstrip patch for tuning at different frequencies when the capacitance range of the non-contact frequency tunable microstrip patch resonator of the present invention is fixed at 0.1-0.9pF (l _i) Frequency change graph of the following.

The numbers in the figures are as follows: 1-microstrip patch, 2-variable capacitor, 3-metalized through hole, 4-metalized through hole, 5-top substrate, 6-microstrip line for frequency tuning, 7-metalized through hole, 8-bottom substrate and 9-metal ground.

Detailed Description

The invention is further described with reference to the following figures and specific embodiments.

As shown in fig. 1 to fig. 3, the frequency tunable microstrip resonator loaded with the non-contact variable capacitor according to the embodiment of the present invention includes a metal ground 9, a bottom substrate 8, a top substrate 5, and a microstrip patch 1, which are sequentially stacked from bottom to top. The microstrip patch 1 is a rectangular microstrip patch and is arranged in the center of the top substrate 5. A microstrip line 6 for frequency tuning is arranged between the top substrate 5 and the bottom substrate 8, and the microstrip line 6 for frequency tuning is arranged along the central line of the microstrip patch 1. The microstrip line 6 for frequency tuning overlaps the microstrip patch 1 in a non-contact manner via the top substrate 5 (the projection of the microstrip line 6 for frequency tuning on the bottom substrate 8 intersects with the projection of the microstrip patch 1 on the bottom substrate 8, that is, the two projections are partially overlapped), the outer end of the microstrip line 6 for frequency tuning is connected to the variable capacitor 2 loaded on the upper surface of the top substrate 5 through the metalized through hole 4, and the outer end of the variable capacitor 2 is grounded (electrically connected to the metal ground 8) through the metalized through hole 3. As shown, the variable capacitor 2 is disposed on the center line of the microstrip patch 1. The frequency tuning microstrip line 6 and the corresponding variable capacitor 2 form a non-contact frequency tuning structure, and the frequency of the microstrip patch resonator is tuned by adjusting the capacitance value C of the variable capacitor. One side of the microstrip patch 1, which is far away from the variable capacitor 2, is connected with a metal ground 9 through a row of metallized through holes 7 which penetrate through the top substrate 5 and the bottom substrate 8 and have the radius of 0.2mm, so that the short circuit of the side of the microstrip patch 1 is realized, and further the half-cut of the microstrip patch is realized.

The embodiment of the invention optimizes the sizes of all parts of the resonator, and the specific parameters of the resonator are shown in the following table.

Parameter(s)	h 1	l p	l w	w	l	l i	l g
								Value (mm)	0.508	20	10	2	12.5	6.5	60

In the table, the number of the first and second,h ₁the height of the top substrate 5 and the bottom substrate 8,l _pfor the length of the microstrip patch 1,l _w being the width of the microstrip patch 1,win order to the width of the microstrip line 6 for frequency tuning,lin order to be the length of the microstrip line for frequency tuning,l _ithe length of the microstrip line 6 for frequency tuning which is separated from the top substrate 5 and is overlapped with the microstrip patch 1 in a non-contact way, namely the length of the inner end of the microstrip line 6 for frequency tuning which extends into the lower part of the microstrip patch 1,l _gthe side length of the top substrate 5 and the bottom substrate 8. The area of the microstrip patch 1 isl _p×l _p. The top substrate 5 and the bottom substrate 8 are of the type RogersRO4003Having a dielectric constant ofε _r= 3.38, loss tangent tanδ= 2.7×10^-3The volume of the top substrate 5 and the bottom substrate 8 isl _g×l _g×h ₁The base substrate 8 is a double-sided printed circuit board, the upper surface of the double-sided printed circuit board 8 is a microstrip line 6 for frequency tuning, and the lower surface is a metal ground 8.

In the embodiment, a microstrip line which is not in contact with the microstrip patch and is loaded with a variable capacitor is used as a tuning structure to realize the function of reconfigurable resonator frequency. Through eigenmode simulation, the polarization direction of the main mode TM10 is found to be parallel to the x-axis, and the tuning structure is placed along the x-axis in order to conform to the polarization direction of the TM10 mode. The frequency tunable structure is composed of a microstrip line for frequency tuning, the middle layer of which is connected with a variable capacitor 2, the inner end of the variable capacitor 2 is connected with a microstrip line 6 of the middle layer through a metallized through hole 4, and the outer end of the variable capacitor is connected with a microstrip line 6 of the middle layerThe metal ground 9 is connected by means of a metallized via 3. The overlapping area of the microstrip line 6 for frequency tuning and the microstrip patch 1 is controlled by adjusting the variable capacitor 2, so that the reconfiguration of the antenna frequency is realized. The top substrate 5 is arranged between the microstrip line 6 for frequency tuning and the microstrip patch 1, thereby reducing the influence of the loading tunable structure on the radiation performance of the antenna and improving the degree of freedom of design. Simulation results show that the introduction of the tuning structure hardly changes the polarization direction of the TM10 mode, which is very advantageous for maintaining a stable radiation pattern in antenna applications. The length of the overlap of the microstrip line 6 for frequency tuning is defined asl _i 。

In the resonator of this embodiment, the equivalent circuit of the tuning structure can be represented as a capacitor C_iAnd C_vAre connected in series. Wherein, C_iRepresenting the coupling capacitance between the microstrip line for frequency tuning and the microstrip patch resonator, C_vRepresenting the capacitance value of the variable capacitance. In the present design, the downward shift in the resonance frequency is due to the capacitive effect (corresponding to C) caused by the coupling between the microstrip line overlap for tuning and the microstrip patch resonator_i). Meanwhile, in order to realize the function of continuously tuning frequency, a variable capacitor is loaded on the upper surface of the top substrate and is connected with the tail end of a microstrip line for frequency tuning through a metalized through hole, and the capacitance value C of the variable capacitor is adjusted_vTo dynamically adjust the electrical length of the microstrip line.

As shown in fig. 4, the capacitance C due to the variable capacitance_vAnd a coupling capacitor C_iAre in series so that they will collectively affect the operating frequency of the resonator. Therefore, the inventor selects different overlapping lengths of microstrip lines (l _i ) To observe the change in frequency.

FIG. 5 shows the overlapping length of the microstrip line and the microstrip patch for tuning at different frequencies when the frequency tunable microstrip patch resonator loaded by the non-contact variable capacitor is fixed in the capacitance range of 0.1-0.9pF (l _i ) Frequency change graph of the following. The frequency adjustment range is 14.53%, (l _i =7.5）-19.27%( l _i = 9.5). As can be seen from the figure, when variableCapacitor C_vIs fixed at 0.1-0.9pF, the frequency of the main mode TM10 follows C_vAndl _i is increased and is moved down.l _i The larger the frequency tuning range.

In addition to the above embodiments, the present invention may have other embodiments. All technical solutions formed by adopting equivalent substitutions or equivalent transformations fall within the protection scope of the claims of the present invention.