A dielectric waveguide filter

Abstract

The present invention relates to a dielectric waveguide filter. The dielectric waveguide filter is composed of a plurality of dielectric waveguide resonators, and the requirements met by the dielectric waveguide resonators are: the working main modes of the dielectric waveguide resonators are the same or similar, but the harmonic distributions thereof are greatly different. The present invention digs out dielectric blocks of different shapes and sizes on the dielectric waveguide resonator, and adjusts the size of the dielectric waveguide resonator at the same time, so that the working main modes of different dielectric waveguide resonators are the same or similar, but the harmonic distributions thereof are greatly different, and then utilizes these different dielectric waveguide resonators to form a bandpass filter. Since the working main modes of these dielectric waveguide resonators are the same or similar, the passband of the bandpass filter can be designed using the main mode. At the same time, the harmonic distributions of different dielectric waveguide resonators are greatly different, and these harmonics cannot be coupled and transmitted between the resonators, resulting in the harmonics of the formed bandpass filter being effectively suppressed.

Description

Technical Field

[0001] The present invention relates to the technical field of radio frequency communication filtering, and in particular to a dielectric waveguide filter and a harmonic suppression method thereof. Background Art

[0002] With the rapid development of mobile communication technology, mobile communication systems have increasingly higher requirements for bandpass filters that are essential to their RF front-ends, such as miniaturization, lightweight, low loss, and good temperature drift characteristics. Compared with traditional planar transmission lines and metal cavity filters, dielectric waveguide bandpass filters have great advantages in the above performance aspects. Therefore, dielectric waveguide filters have become the mainstream choice for future mobile communication systems. However, the biggest disadvantage of dielectric waveguide filters is the complexity of the resonant mode. There are many resonant modes close to the main working mode, which leads to undesirable parasitic responses close to the passband of the bandpass filter, seriously affecting the stopband suppression performance of the bandpass filter. Therefore, how to design a dielectric waveguide filter with harmonic suppression performance is a very meaningful study. Summary of the invention

[0003] The present invention aims at the technical problem that the harmonic suppression performance of the dielectric waveguide filter in the prior art is poor, and proposes a dielectric waveguide filter and a harmonic suppression method thereof, thereby filling the technical gap in the prior art in this technical field.

[0004] To this end, the technical solution adopted by the present invention is: a dielectric waveguide filter, the dielectric waveguide filter is composed of a plurality of dielectric waveguide resonators, and the requirements met by each dielectric waveguide resonator are: the working main modes of each dielectric waveguide resonator are the same or similar, but the harmonic distributions thereof are greatly different.

[0005] Furthermore, the main mode difference of each dielectric waveguide resonator is smaller than the passband bandwidth of the dielectric waveguide filter.

[0006] Furthermore, the harmonic distribution of each dielectric waveguide satisfies that the difference is greater than twice the passband bandwidth of the dielectric waveguide filter.

[0007] Furthermore, the method for satisfying the requirements of the main mode and harmonic distribution of the dielectric waveguide resonator is as follows: dielectric blocks of different shapes and sizes are dug out from the dielectric waveguide resonator, and the size of the dielectric waveguide resonator is adjusted at the same time.

[0008] Furthermore, the removed medium block may be cylindrical, rectangular, or a combination thereof.

[0009] Furthermore, when the dielectric waveguide resonators are combined into the dielectric waveguide filter: the front-end dielectric waveguide resonator is provided with an input port structure, and the rear-end dielectric waveguide resonator is provided with an output port structure; the front-end and rear-end dielectric waveguide resonators are provided with feeding structures; and signal coupling transmission is formed between adjacent dielectric waveguide resonators through coupling windows.

[0010] Furthermore, the dielectric blocks dug out of the resonators constituting the filter may be consistent; or a part of the resonators may have dielectric blocks of one shape dug out, and another part of the resonators may have dielectric blocks of another shape dug out.

[0011] Furthermore, only one type of dielectric block may be dug out from each resonator, or dielectric blocks of multiple different types of dielectric blocks may be dug out from each resonator.

[0012] Furthermore, when dielectric blocks of various shapes are cut out from the resonator, the cutout dielectric blocks may form a connected structure or a discontinuous structure.

[0013] Furthermore, circular grooves are etched on the bottom surfaces of the frontmost resonator and the rearmost resonator respectively to serve as signal input and output ports; and a cylindrical dielectric block is dug out from under the frontmost resonator and the rearmost resonator respectively to form a feeding structure.

[0014] The main idea of ​​the harmonic suppression method proposed in the present invention is to dig out dielectric blocks of different shapes and sizes on the dielectric waveguide resonator, and adjust the size of the dielectric waveguide resonator at the same time, so that the working main modes of different dielectric waveguide resonators are the same or similar, but their harmonic distributions are quite different, and then use these different dielectric waveguide resonators to form a bandpass filter. Since the working main modes of these dielectric waveguide resonators are the same or similar, the passband of the bandpass filter can be designed using the main mode. At the same time, the harmonic distributions of different dielectric waveguide resonators are quite different, and these harmonics cannot be coupled and transmitted between the resonators, resulting in the harmonics of the formed bandpass filter being effectively suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 , 2 It is a schematic structural diagram of the dielectric waveguide resonator of the present invention.

[0016] Figure 3 This is a schematic structural diagram of Embodiment 1 of the dielectric waveguide filter provided by the present invention.

[0017] Figure 4 The simulation results of the dielectric waveguide filter embodiment 1 provided by the present invention.

[0018] Figure 5 This is a schematic structural diagram of Embodiment 2 of the dielectric waveguide filter provided by the present invention.

[0019] Figure 6 This is a schematic structural diagram of Embodiment 3 of the dielectric waveguide filter provided by the present invention. DETAILED DESCRIPTION

[0020] A dielectric waveguide filter is composed of a plurality of dielectric waveguide resonators. The dielectric waveguide resonators meet the following requirements: the working main modes of the dielectric waveguide resonators are the same or similar, but the harmonic distributions thereof are greatly different.

[0021] Furthermore, the main mode difference of each dielectric waveguide resonator is smaller than the passband bandwidth of the dielectric waveguide filter.

[0022] Furthermore, the harmonic distribution of each dielectric waveguide satisfies that the difference is greater than twice the passband bandwidth of the dielectric waveguide filter.

[0023] Furthermore, the method for satisfying the requirements of the main mode and harmonic distribution of the dielectric waveguide resonator is as follows: dielectric blocks of different shapes and sizes are dug out from the dielectric waveguide resonator, and the size of the dielectric waveguide resonator is adjusted at the same time.

[0024] Furthermore, the removed medium block may be cylindrical, rectangular, or a combination thereof.

[0025] Furthermore, when the dielectric waveguide resonators are combined into the dielectric waveguide filter: the front-end dielectric waveguide resonator is provided with an input port structure, and the rear-end dielectric waveguide resonator is provided with an output port structure; the front-end and rear-end dielectric waveguide resonators are provided with feeding structures; and signal coupling transmission is formed between adjacent dielectric waveguide resonators through coupling windows.

[0026] Furthermore, the dielectric blocks dug out of the resonators constituting the filter may be consistent; or a part of the resonators may have dielectric blocks of one shape dug out, and another part of the resonators may have dielectric blocks of another shape dug out.

[0027] Furthermore, only one type of dielectric block may be dug out from each resonator, or dielectric blocks of multiple different types of dielectric blocks may be dug out from each resonator.

[0028] Furthermore, when dielectric blocks of various shapes are cut out from the resonator, the cutout dielectric blocks may form a connected structure or a discontinuous structure.

[0029] Furthermore, circular grooves are etched on the bottom surfaces of the frontmost resonator and the rearmost resonator respectively to serve as signal input and output ports; and a cylindrical dielectric block is dug out from under the frontmost resonator and the rearmost resonator respectively to form a feeding structure.

[0030] The present invention is further described below to better understand the present invention:

[0031] The specific filter design is as follows:

[0032] First, a dielectric waveguide resonator with different shapes and sizes of dielectric blocks dug out was designed, such as Figure 1 The dielectric waveguide resonator shown has a shorter cylindrical dielectric block dug out. Figure 2 The dielectric waveguide resonator in the embodiment of FIG. 1 is formed by digging out a longer cylindrical dielectric block. The cylindrical dielectric block dug out here can also be of other shapes. By adjusting Figure 1 The sizes of the two dielectric waveguide resonators and the size of the removed dielectric block make their main modes the same or similar, while their harmonic distributions are quite different.

[0033] use Figure 1 A fourth-order dielectric waveguide filter is designed based on the two dielectric waveguide resonators in Figure 3 As shown in FIG. 1 , it is composed of four dielectric waveguide resonators, and the outer surface of the overall structure is metallized. Resonator 1 and resonator 4 are made of Figure 1 The dielectric waveguide resonators shown, resonator 2 and resonator 3 use Figure 2 The dielectric waveguide resonator shown. Circular grooves are etched on the bottom surfaces of resonator 1 and resonator 4 respectively as signal input and output ports. A cylindrical dielectric block is dug out from the bottom of resonator 1 and resonator 4 respectively to form a feeding structure, namely feeding cylinder 1 and feeding cylinder 2. Signal coupling transmission is formed between resonator 1 and resonator 2 through coupling window 1, signal coupling transmission is formed between resonator 2 and resonator 3 through coupling window 2, and signal coupling transmission is formed between resonator 3 and resonator 4 through coupling window 3.

[0034] The working principle of the entire filter is as follows: the signal is input into resonator 1 through annular groove 1 and feeding cylinder 1, coupled to resonator 2 through coupling window 1, coupled to resonator 3 through coupling window 2, coupled to resonator 4 through coupling window 3, and finally output by feeding cylinder 2 and annular groove 2.

[0035] In the electromagnetic simulation software, Figure 2 The fourth-order dielectric waveguide filter shown in the figure is subjected to electromagnetic simulation and optimized to obtain the following Figure 4 The simulated S parameters are shown in Figure 2. The working passband of the designed filter is from 2.5GHz to 2.7GHz, and the upper stopband suppression is 40dB to 5.5GHz.

[0036] like Figure 5 FIG. 1 is a schematic diagram showing another embodiment of a dielectric waveguide filter provided by the present invention. In this embodiment, the dielectric waveguide filter and Figure 3The structure of the dielectric waveguide filter shown in FIG. 1 is basically the same as that of FIG. 1 , except that in this embodiment, the dielectric blocks hollowed out in the two dielectric resonators are rectangular.

[0037] like Figure 6 FIG. 1 is a schematic diagram showing another embodiment of a dielectric waveguide filter provided by the present invention. In this embodiment, the dielectric waveguide filter and Figure 6 The structure of the dielectric waveguide filter shown in FIG. 1 is basically the same, except that in this embodiment, the dielectric blocks hollowed out in all dielectric resonators are rectangular.

[0038] After simulation, Figure 5 , 6 The dielectric waveguide filter has a good harmonic suppression effect.

[0039] The dielectric block of the present invention may be formed into dielectric blocks of other shapes in addition to the above-mentioned cylindrical and square shapes, all of which have good harmonic suppression effects.

Claims

1. A dielectric waveguide filter, characterized in that: The dielectric waveguide filter is composed of a plurality of dielectric waveguide resonators, and the requirements that each dielectric waveguide resonator meets are: the working main mode of each dielectric waveguide resonator is the same, and the difference in harmonic distribution of each dielectric waveguide resonator is greater than twice the passband bandwidth of the dielectric waveguide filter; The main modes of each dielectric waveguide resonator satisfy that the difference is smaller than the passband bandwidth of the dielectric waveguide filter; The method for meeting the requirements of the main mode and harmonic distribution of the dielectric waveguide resonator is as follows: digging out dielectric blocks of different shapes and sizes on the dielectric waveguide resonator and adjusting the size of the dielectric waveguide resonator; When the dielectric waveguide resonators are combined into the dielectric waveguide filter: the front-end dielectric waveguide resonator is provided with an input port structure, and the rear-end dielectric waveguide resonator is provided with an output port structure; the front-end and rear-end dielectric waveguide resonators are provided with feeding structures; and signal coupling transmission is formed between adjacent dielectric waveguide resonators through coupling windows; Among the resonators constituting the dielectric waveguide filter, a portion of the resonators have dielectric blocks of one shape hollowed out, and another portion of the resonators have dielectric blocks of another shape hollowed out; Circular grooves are etched on the bottom surfaces of the frontmost resonator and the rearmost resonator respectively to serve as signal input and output ports; A cylindrical dielectric block is dug out from under the frontmost resonator and the rearmost resonator to form a feeding structure.

2. A dielectric waveguide filter according to claim 1, characterized in that: The excavated medium block is cylindrical, rectangular or a combination thereof.

3. A dielectric waveguide filter according to claim 1, characterized in that: The dielectric blocks dug out from the resonator form a connected or discontinuous structure.

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