Microstrip linear filter, duplexer and radio-frequency device

Abstract

The invention discloses a microstrip line filter, which comprises a chamber which is provided with a PCB plate; the top and bottom inner wall of the PCB plate and the chamber are provided with a certain air height; the two sides of the PCB plate are both provided with corresponding cross cascaded transmission line and the cross cascaded transmission line arranged on one side of the PCB plate is connected with the transmission line on the other side through a hole. The invention also discloses a corresponding duplexer and a radio-frequency device. The embodiment of the invention has the advantages of simple producing processing, high quality rate, low transmission loss, low cost, etc.

Description

technical field [0001] The invention relates to the technical field of communication, in particular to a microstrip line filter, a duplexer and a radio frequency device composed of the filter. Background technique [0002] With the rapid development of wireless communication technology, communication equipment of various frequency bands and standards are constantly appearing and put into use. In order to avoid mutual interference between signals of various communication systems, including the transmission and reception of their own systems, radio frequency filters are required for filtering. Especially on a radio frequency device (such as a wireless base station), in order to realize receiving and transmitting signals on the same antenna, a duplexer needs to be used. [0003] Such as figure 1 Shown is a structural schematic diagram of an existing duplexer; the duplexer adopts the form of a cavity dielectric filter. The geometry of the cavity determines the resonant frequen...

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Problems solved by technology

so figure 2 In the duplexer, if the general PCB board is used, the overall loss is relatively large; if low loss is to be achieved, for example, in some high-frequency applications, it is necessary to use a high-grade RF board with a low loss tangent ( Such as RO3003 and other boards), but the price of this board is generally high and the cost is high; moreover, the material of high-grade radio frequency boards is generally soft, if the assembly is not done properly, the deformation of the PCB board will easily lead to changes in the indicators;

[0011] In addition, due to the influence of the high-frequency skin effect of the conductor

The effective conduction cross-sectional area of ​​the microstrip conductor is reduced, resulting in an increase in high-frequency loss, which is also the largest part of the microstrip loss

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