Novel filter applied to GNSS antenna

Abstract

The utility model relates to the technical field of antenna filters, and discloses a novel filter applied to a GNSS (Global Navigation Satellite System) antenna, which comprises a novel GNSS antenna filter, a front port and a rear port of the novel GNSS antenna filter are respectively connected with a front-stage low-noise amplifier and a rear-stage low-noise amplifier, the front-stage low-noise amplifier is used for amplifying front-stage GNSS signals, and the rear-stage low-noise amplifier is used for amplifying rear-stage GNSS signals. The novel GNSS antenna filter is used for filtering and combining preceding-stage GNSS signals at different frequency bands, and the novel GNSS antenna filter is directly composed of a plurality of stages of Chebyshev filters and a plurality of stages of wave traps. According to the utility model, the novel filter has the advantages of simple and novel structure and flexible design, can better match the impedance of the circuit under the condition of ensuring the insertion loss and out-of-band rejection of GNSS signals, has wide application prospect and remarkable market value, and is suitable for various high-precision GNSS navigation positioning systems.

Description

Technical Field

[0001] This utility model relates to the field of antenna filter technology, and in particular to a novel filter for use in GNSS antennas. Background Technology

[0002] With the widespread application of Global Navigation Satellite Systems (GNSS), such as GPS and BeiDou, the performance requirements for GNSS antennas are becoming increasingly stringent. When receiving satellite signals, GNSS antennas simultaneously receive interference signals from other frequency bands, such as mobile communication bands and wireless LAN bands. These interference signals can severely affect the accuracy and stability of GNSS antenna signal reception, reducing positioning accuracy. Therefore, designing effective filters in GNSS antennas to suppress interference signals is crucial.

[0003] In the process of developing this application, the inventors discovered the following problems with the prior art: Currently, most traditional filters are surface acoustic wave (SAW) filters or ceramic filters. However, SAW filters or ceramic filters have problems such as insufficient filtering performance and poor matching with antennas, making it difficult to meet the current development needs of GNSS antennas. Therefore, those skilled in the art have provided a novel filter for GNSS antennas to solve the problems mentioned in the background art. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a novel filter for GNSS antennas. This novel filter has a simple, novel, and flexible design. While ensuring the insertion loss and out-of-band suppression of GNSS signals, it can also better match the impedance of the circuit. It has broad application prospects and significant market value, and is suitable for various high-precision GNSS navigation and positioning systems.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A novel filter for use with GNSS antennas includes a novel GNSS antenna filter, wherein a pre-stage low-noise amplifier and a post-stage low-noise amplifier are respectively connected to the front and rear ports of the novel GNSS antenna filter. The pre-stage low-noise amplifier is used to amplify the GNSS signal of the pre-stage. The novel GNSS antenna filter performs frequency band filtering and combining on the GNSS signal of the pre-stage. The novel GNSS antenna filter is directly composed of multi-stage Chebyshev filters and multi-stage notch filters.

[0007] Furthermore, both the multi-stage Chebyshev filter and the multi-stage notch filter are internally equipped with single-stage LC components. The single-stage LC components of the multi-stage Chebyshev filter and the multi-stage notch filter are attached to the PCB board. Each of the multiple single-stage LC components is a single stage. The multi-stage Chebyshev filter has no fewer than 9 stages, and the multi-stage notch filter has no fewer than 2 stages.

[0008] Furthermore, all of the aforementioned single-stage LC components are lumped devices.

[0009] Furthermore, the multiple single-stage LC components adopt a combination of lumped devices and distributed devices, wherein the distributed devices are high-impedance microstrip lines with open ends and high-impedance microstrip lines with short ends to ground.

[0010] This utility model has the following beneficial effects:

[0011] This invention proposes a novel filter for GNSS antennas. By combining a multi-stage Chebyshev filter and a multi-stage notch filter to form a novel GNSS antenna filter, the front and rear ports of the filter can be directly connected to the front and rear low-noise amplifiers of the GNSS antenna circuit, respectively. The single-stage LC components of the bandpass filter and the multi-stage notch filter are attached to the PCB board, with each single-stage LC component constituting one stage. The multi-stage Chebyshev filter has at least 9 stages, and the multi-stage notch filter has at least 2 stages. The bandwidth of the bandpass filter can cover the 1.175GHz~1.615GHz frequency band, and the bandwidth of the multi-stage notch filter can cover the 1.368GHz~1.44GHz bandwidth. In principle, this design solves the problem of the traditional GNSS antenna filter architecture of first splitting, then filtering by frequency band, and finally combining. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the GNSS antenna filter architecture of this utility model;

[0013] Figure 2 This is a schematic diagram of a traditional GNSS antenna filter architecture;

[0014] Figure 3 This is a schematic diagram of the GNSS antenna filter of this utility model;

[0015] Figure 4 This is an extended view of the schematic diagram of the GNSS antenna filter of this utility model;

[0016] Figure 5 The simulation results are shown as an extension of the schematic diagram of the novel filter.

[0017] Legend:

[0018] 100. New type of GNSS antenna filter; 101. Multi-stage Chebyshev filter; 102. Multi-stage notch filter; 103. Single-stage LC component. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] Reference Figures 1 to 5 A novel filter for GNSS antennas includes a novel GNSS antenna filter 100. The front and rear ports of the novel GNSS antenna filter 100 are respectively connected to a pre-stage low-noise amplifier and a post-stage low-noise amplifier. The pre-stage low-noise amplifier is used to amplify the GNSS signal of the pre-stage. The novel GNSS antenna filter 100 performs frequency band filtering and combining on the GNSS signal of the pre-stage. The novel GNSS antenna filter 100 is directly composed of a multi-stage Chebyshev filter 101 and a multi-stage notch filter 102.

[0021] Specifically, by directly connecting the front and rear ports of the new GNSS antenna filter 100 to the front-stage and rear-stage low-noise amplifiers of the GNSS antenna circuit, respectively, the entire new GNSS antenna filter 100 can be directly composed of a bandpass filter and a notch filter for the GNSS system signal bandwidth. At the same time, the new GNSS antenna filter 100 can perform frequency-band filtering and combining of the front-stage GNSS signal. In contrast, in the traditional GNSS antenna filter architecture, after the GNSS signal is amplified in the front stage, it is first split, then passed through the low-frequency filter and high-frequency wave of GNSS separately, and then combined. The new GNSS antenna filter 100 eliminates the combiner and splitter, thereby reducing the insertion loss of the combiner and splitter, reducing the noise figure, and improving the system signal-to-noise ratio.

[0022] Reference Figure 3 Both the multi-stage Chebyshev filter 101 and the multi-stage notch filter 102 have a single-stage LC component 103 inside. The single-stage LC component 103 of the multi-stage Chebyshev filter 101 and the multi-stage notch filter 102 are attached to the PCB board. The multiple single-stage LC components 103 are all of the same level. The multi-stage Chebyshev filter 101 has no fewer than 9 stages, and the multi-stage notch filter 102 has no fewer than 2 stages.

[0023] Specifically, after assembling a new multi-stage filter composed of a broadband bandpass filter and a notch filter, the LC component can be attached to the PCB board. The new GNSS antenna filter 100 is composed of a multi-stage Chebyshev filter and a multi-stage notch filter. The multi-stage Chebyshev filter 101 and the multi-stage notch filter 102 are composed of a 9-stage Chebyshev filter and a 2-stage notch filter.

[0024] Reference Figure 3 and Figure 4 The multiple single-stage LC components 103 are all lumped devices. The multiple single-stage LC components 103 are a combination of lumped devices and distributed devices. The distributed devices are high-impedance microstrip lines with open ends and high-impedance microstrip lines with short ends to ground.

[0025] Specifically, in the single-stage LC component 103 of the multi-stage Chebyshev filter and the multi-stage notch filter, each stage consists of an inductor and a capacitor. Each capacitor and each inductor are designed according to the center frequency and bandwidth requirements of the GNSS operating band. Some small inductors use high-impedance distributed microstrip transmission lines to replace lumped inductors, ultimately meeting the performance requirements of high-precision GNSS antenna filters.

[0026] Working principle: This GNSS antenna filter is composed of a broadband pass filter and a notch filter directly cascaded, eliminating the traditional splitter and combiner structure. It adopts a combination of a multi-stage Chebyshev filter 101 and a multi-stage notch filter 102, which can cover the GNSS frequency band and suppress the interference frequency band. The single-stage LC component 103 adopts a hybrid lumped device and a distributed high-impedance microstrip line. Relying on the PCB layout to optimize impedance matching, it achieves low insertion loss and high out-of-band rejection, thereby improving anti-interference capability and positioning accuracy.

[0027] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A novel filter for use with GNSS antennas, comprising a novel GNSS antenna filter (100), characterized in that: The novel GNSS antenna filter (100) has a front-stage low-noise amplifier and a rear-stage low-noise amplifier connected to its front and rear ports, respectively. The front-stage low-noise amplifier is used to amplify the GNSS signal of the front stage. The novel GNSS antenna filter (100) performs frequency band filtering and combining on the GNSS signal of the front stage. The novel GNSS antenna filter (100) is directly composed of a multi-stage Chebyshev filter (101) and a multi-stage notch filter (102).

2. A novel filter for GNSS antennas according to claim 1 characterized by: Both the multi-stage Chebyshev filter (101) and the multi-stage notch filter (102) are internally equipped with single-stage LC components (103). The single-stage LC components (103) of the multi-stage Chebyshev filter (101) and the multi-stage notch filter (102) are attached to the PCB board. Each of the single-stage LC components (103) is a single stage. The multi-stage Chebyshev filter (101) has no fewer than 9 stages, and the multi-stage notch filter (102) has no fewer than 2 stages.

3. A novel filter for application to GNSS antennas according to claim 2, characterized in that: All of the single-stage LC components (103) mentioned above are lumped devices.

4. A novel filter for application to GNSS antennas according to claim 3, characterized in that: The multiple single-stage LC components (103) are selected in the form of a combination of lumped devices and distributed devices. The distributed devices are high-resistivity microstrip lines with open ends and high-resistivity microstrip lines with short ends to ground.

Images