Hairpin type dual passband electrically-tunable microwave filter

Abstract

The invention discloses a hairpin type dual passband electrically-tunable microwave filter. The filter structurally comprises three layers including a metal microstrip line on the obverse side, a dielectric-slab layer in the middle and a metal coating on the reverse side of the dielectric-slab layer, wherein the metal microstrip line is connected with an input and output port and grounding metal through holes. The metal microstrip line is structurally characterized in that an open loop dual-mode resonator of a symmetrical structure is composed of two SIR resonators and resonator middle center branches, in this way, the odd and even mode theory can be used for analysis, variable capacitance diodes are loaded between the tail ends of the open loop dual-mode resonator and certain grounding metal through hole, capacitors are additionally arranged between the tail ends of the resonator middle center short-circuit branches of the open loop dual-mode resonator and the other grounding metal through holes, and the tunable structure is formed. The filter is high in turning speed, wide in working band, easy to integrate and low in cost and meets the development tendency of filter miniaturization.

Description

technical field

[0001] The invention relates to a hairpin type dual-band electrically tunable microwave filter, which belongs to the field of wireless communication systems. Background technique

[0002] The rapid development of communication technology has accelerated global integration and informatization. The ever-expanding huge amount of information requires communication technology to transmit faster, increase transmission bandwidth, and increase information capacity. Modern communication systems gradually begin to have complex spatial domains and frequencies. domain, often loading information on two or several discontinuous channels onto the same beam to be emitted. The dual-pass-band microwave filter can well solve the problem of transmitting signals of two different microwave band frequencies on the same beam, and at the same time suppress stray noise signals, so that the structure of the entire communication system is optimized. However, the dynamic range of the tr...

Examples

Embodiment 1

[0030] see figure 1 , The hairpin type dual-passband tunable filter includes a three-layer structure: a metal microstrip line (1) on the front, a dielectric plate layer (2) in the middle and a metal plating layer on the reverse side of the dielectric plate. The metal microstrip line (1) is connected with input and output ports (3, 4) and a ground metal through hole (5). The structure of the metal microstrip line is: a resonator with a symmetrical structure composed of two SIR resonators (1-1) and a central branch (1-2) in the middle of the resonator, so it can be analyzed by odd-even mode theory. A varactor diode D is loaded between the end of the ring double-mode resonator and the grounding metal through hole (5-1), and the center of the open-loop double-mode resonator is short-circuited between the end of the branch (1-2) and the grounding metal through hole (5-2). A capacitor C is added between ) to form a tunable structure.

Embodiment 2

[0032] This embodiment is basically the same as the first embodiment, and the metal microstrip line on the front is such as figure 2 , the special feature is that the open-loop dual-mode resonator is a resonator with a symmetrical structure composed of two SIR resonators (1-1) and a central branch (1-2) in the middle of the resonator. Its structure is symmetrical, resulting in two the resonant frequency of the mode. The SIR resonator adopts a hairpin structure, and the short-circuit branch (1-2) of the resonator can well control the center frequency of the second harmonic. The input and output coupling lines (3, 4) pass through the tapered gradient line When the load voltage is low, an additional limited frequency transmission zero point is added, which improves the attenuation characteristics of the filter. The dielectric plate layer is the dielectric constant The thickness of the dielectric plate is h = 0.8~1.0mm.

Embodiment 3

[0034] This embodiment is basically the same as the second embodiment, except that a varactor diode D is loaded between the open-loop dual-mode resonator and the grounded metal through hole (5-1), and the middle central branch (1-2) of the resonator is connected to the Load capacitor C ( image 3 ), load the reverse bias voltage to the varactor diode D through the DC bias circuit, and change the resonant frequency of the odd-even mode to achieve the purpose of adjusting the center frequency and bandwidth of the band-pass filter.

[0035] Figure 4 It is a schematic structural diagram of this embodiment. After design, simulation and optimization, the specific dimensions of the multi-pass band tunable band-pass filter are finally determined as follows:

[0036] L 1 =1.9mm,L 2 =8mm,L 3 =8.6mm, W 0 =2.16mm, W 1 =0.5mm,

[0037] W 2 =1.3mm, S=0.3mm, h=4.6mm, g=0.6mm, d 0 =2.5mm,

[0038] m=0.12mm, t=2mm

[0039] Based on the above method, a dual-pass-band microstrip filt...

technical field

[0001] The invention relates to a hairpin type dual-band electrically tunable microwave filter, which belongs to the field of wireless communication systems. Background technique

[0002] The rapid development of communication technology has accelerated global integration and informatization. The ever-expanding huge amount of information requires communication technology to transmit faster, increase transmission bandwidth, and increase information capacity. Modern communication systems gradually begin to have complex spatial domains and frequencies. domain, often loading information on two or several discontinuous channels onto the same beam to be emitted. The dual-pass-band microwave filter can well solve the problem of transmitting signals of two different microwave band frequencies on the same beam, and at the same time suppress stray noise signals, so that the structure of the entire communication system is optimized. However, the dynamic range of the tr...

Examples

Embodiment 1

[0030] see figure 1 , The hairpin type dual-passband tunable filter includes a three-layer structure: a metal microstrip line (1) on the front, a dielectric plate layer (2) in the middle and a metal plating layer on the reverse side of the dielectric plate. The metal microstrip line (1) is connected with input and output ports (3, 4) and a ground metal through hole (5). The structure of the metal microstrip line is: a resonator with a symmetrical structure composed of two SIR resonators (1-1) and a central branch (1-2) in the middle of the resonator, so it can be analyzed by odd-even mode theory. A varactor diode D is loaded between the end of the ring double-mode resonator and the grounding metal through hole (5-1), and the center of the open-loop double-mode resonator is short-circuited between the end of the branch (1-2) and the grounding metal through hole (5-2). A capacitor C is added between ) to form a tunable structure.

Embodiment 2

[0032] This embodiment is basically the same as the first embodiment, and the metal microstrip line on the front is such as figure 2 , the special feature is that the open-loop dual-mode resonator is a resonator with a symmetrical structure composed of two SIR resonators (1-1) and a central branch (1-2) in the middle of the resonator. Its structure is symmetrical, resulting in two the resonant frequency of the mode. The SIR resonator adopts a hairpin structure, and the short-circuit branch (1-2) of the resonator can well control the center frequency of the second harmonic. The input and output coupling lines (3, 4) pass through the tapered gradient line When the load voltage is low, an additional limited frequency transmission zero point is added, which improves the attenuation characteristics of the filter. The dielectric plate layer is the dielectric constant The thickness of the dielectric plate is h = 0.8~1.0mm.

Embodiment 3

[0034] This embodiment is basically the same as the second embodiment, except that a varactor diode D is loaded between the open-loop dual-mode resonator and the grounded metal through hole (5-1), and the middle central branch (1-2) of the resonator is connected to the Load capacitor C ( image 3 ), load the reverse bias voltage to the varactor diode D through the DC bias circuit, and change the resonant frequency of the odd-even mode to achieve the purpose of adjusting the center frequency and bandwidth of the band-pass filter.

[0035] Figure 4 It is a schematic structural diagram of this embodiment. After design, simulation and optimization, the specific dimensions of the multi-pass band tunable band-pass filter are finally determined as follows:

[0036] L 1 =1.9mm,L 2 =8mm,L 3 =8.6mm, W 0 =2.16mm, W 1 =0.5mm,

[0037] W 2 =1.3mm, S=0.3mm, h=4.6mm, g=0.6mm, d 0 =2.5mm,

[0038] m=0.12mm, t=2mm

[0039] Based on the above method, a dual-pass-band microstrip filt...

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