CN220544985U

CN220544985U - 100 MHz-500 MHz low rectangular coefficient electrically tunable filter circuit

Info

Publication number: CN220544985U
Application number: CN202321997922.5U
Authority: CN
Inventors: 贾坤; 李青; 吴妃堂; 罗志伟; 雷镇玮; 陈俊佐
Original assignee: Guiyang Sunlord Xunda Electronic Component Co ltd
Current assignee: Guiyang Sunlord Xunda Electronic Component Co ltd
Priority date: 2023-07-27
Filing date: 2023-07-27
Publication date: 2024-02-27
Anticipated expiration: 2033-07-27

Abstract

The utility model discloses a 100 MHz-500 MHz low rectangular coefficient electrically tunable filter circuit, which comprises a second order filter and a second order filter, wherein the first order filter comprises a first capacitor, a third inductor, a first inductor, a second inductor, a fourth inductor and a second capacitor, a fifth inductor is connected between the third inductor and the first inductor in a tap mode, a sixth inductor and an eighth inductor are connected between the second inductor and the fourth inductor in a tap mode in sequence, the second order filter comprises a fourth capacitor, a tenth inductor, a twelfth inductor, an eleventh inductor, a ninth inductor and a third capacitor which are connected in series in sequence, the tap between the tenth inductor and the twelfth inductor is connected to the eighth inductor, the tap between the eleventh inductor and the ninth inductor is connected to the seventh inductor, and the tap between the first capacitor, the first inductor and the second inductor and the tap between the eleventh inductor and the ninth inductor are grounded. The rectangular coefficient of 40dB bandwidth/3 dB bandwidth of the utility model can reach 2.7, and the anti-interference capability is better.

Description

100 MHz-500 MHz low rectangular coefficient electrically tunable filter circuit

Technical Field

The utility model relates to a 100 MHz-500 MHz low rectangular coefficient electrically tunable filter circuit, and belongs to the technical field of electrically tunable filter test equipment.

Background

With the increasing requirements of equipment practicability and environmental adaptability, a filter with a low rectangular coefficient is required to be used, so that the anti-interference capability of communication is ensured; as shown in the figure 1, the rectangular coefficient of 40dB bandwidth/3 dB bandwidth of the conventional 100 MHz-500 MHz electrically tunable filter cannot be less than or equal to 5, so that the anti-interference capability of the whole machine communication is greatly reduced.

Disclosure of Invention

The utility model aims to solve the technical problems that: provides a 100 MHz-500 MHz low rectangular coefficient electrically tunable filter circuit to solve the problems in the prior art.

The technical scheme adopted by the utility model is as follows: a100 MHz-500 MHz low rectangular coefficient electrically tunable filter circuit comprises a first second filter and a second filter which are connected in series, wherein the first second filter comprises a first capacitor C1, a third inductor L3, a first inductor L1, a second inductor L2, a fourth inductor L4 and a second capacitor C2 which are sequentially connected, a fifth inductor L5 is connected between the third inductor L3 and the first inductor L1 in a tap mode, a sixth inductor L6 and an eighth inductor L8 are sequentially connected between the second inductor L2 and the fourth inductor L4 in a tap mode, the second filter comprises a fourth capacitor C4, a tenth inductor L10, a twelfth inductor L12, an eleventh inductor L11, a ninth inductor L9 and a third capacitor C3 which are sequentially connected in a tap mode, the tap between the tenth inductor L10 and the twelfth inductor L12 is connected to the eighth inductor L8, the tap between the eleventh inductor L11 and the ninth inductor L9 is connected to the seventh inductor L7, and the tap between the first inductor C1, the second inductor C2, the third inductor C3, the fourth inductor C4 and the tap between the fourth inductor L1 and the ninth inductor L2 are sequentially connected in a tap mode.

The utility model has the beneficial effects that: compared with the prior art, the utility model connects two-order filters in series to form the fourth-order filter, the product size is increased, the rectangular coefficient of 40dB bandwidth/3 dB bandwidth is reduced, the rectangular coefficient is reduced to 2.7, and the anti-interference capability of the fourth-order filter is better.

Drawings

FIG. 1 is a schematic diagram of a conventional 100MHz to 500MHz electrically tunable filter;

FIG. 2 is a schematic diagram of a circuit structure of a 100 MHz-500 MHz low rectangular coefficient electrically tunable filter.

Detailed Description

The utility model will be further described with reference to the accompanying drawings and specific examples.

Example 1: as shown in FIG. 2, a 100 MHz-500 MHz low rectangular coefficient electrically tunable filter circuit comprises a first second filter and a second filter which are connected in series, wherein the first filter comprises a first capacitor C1, a third inductor L3, a first inductor L1, a second inductor L2, a fourth inductor L4 and a second inductor C2 in sequence, a fifth inductor L5 is connected between the third inductor L3 and the first inductor L1 in a tap manner, a sixth inductor L6 and an eighth inductor L8 are connected between the second inductor L2 and the fourth inductor L4 in sequence, the second filter comprises a fourth inductor C4, a tenth inductor L10, a twelfth inductor L12, an eleventh inductor L11, a ninth inductor L9 and a third inductor C3 in series in sequence, a tap between the tenth inductor L10 and the twelfth inductor L12 is connected to the eighth inductor L8, a tap between the eleventh inductor L11 and the ninth inductor L9 is connected to the seventh inductor L7, and a tap between the first inductor C1, the second inductor C2, the third inductor C3, the fourth inductor C4 and the ninth inductor L1 in a tap manner between the fourth inductor L1 and the ninth inductor L2 in sequence. The two-order filters are connected in series to form a fourth-order filter, the size of the product is increased, the rectangular coefficient of 40dB bandwidth/3 dB bandwidth is reduced, the rectangular coefficient is reduced to 3.5, and the anti-interference capability of the fourth-order filter is better. The other ends of the fifth inductor L5 and the seventh inductor L7 are respectively a signal input end and a signal output end. The first capacitor C1, the second capacitor C2, the third capacitor C3 and the fourth capacitor C4 all adopt varactors, and tuning voltage controls each group of varactors, so that each group of capacitance is changed, and the purposes of changing resonance frequency and realizing frequency conversion are achieved.

The performance parameters of the utility model are as follows:

the foregoing is merely illustrative of the present utility model, and the scope of the present utility model is not limited thereto, and any person skilled in the art can easily think about variations or substitutions within the scope of the present utility model, and therefore, the scope of the present utility model shall be defined by the scope of the appended claims.

Claims

1. A100 MHz-500 MHz low rectangular coefficient electrically tunable filter circuit is characterized in that: the second-order filter comprises a first second-order filter and a second-order filter which are connected in series, wherein the first second-order filter comprises a first capacitor C1, a third inductor L3, a first inductor L1, a second inductor L2, a fourth inductor L4 and a second capacitor C2 in sequence, a tap between the third inductor L3 and the first inductor L1 is connected with a fifth inductor L5, a tap between the second inductor L2 and the fourth inductor L4 is sequentially connected with a sixth inductor L6 and an eighth inductor L8, the second-order filter comprises a fourth capacitor C4, a tenth inductor L10, a twelfth inductor L12, an eleventh inductor L11, a ninth inductor L9 and a third capacitor C3 which are sequentially connected in series, a tap between the tenth inductor L10 and the twelfth inductor L12 is connected with an eighth inductor L8, a tap between the eleventh inductor L11 and the ninth inductor L9 is connected with a seventh inductor L7, and a tap between the first inductor L1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4, a tap between the first inductor L1 and the second inductor L2, and a tap between the eleventh inductor L11 and a ninth inductor L9 are all connected with the ground.