Filter with two-path filtering function
By using two bridges, two fixed frequency bandpass filters and one variable frequency hopping filter in the filter, the filtering in the existing technology is solved by using 3dB bridge combined with two frequency signals. The problem of cost and volume increase when combining the device achieves flexible and efficient filtering effect.
Patent Information
- Application Number
- CN202421229306.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-31
- Publication Date
- 2025-02-14
- Estimated Expiration
- 2034-05-31
AI Technical Summary
In the prior art, when implementing the merger of two filters, the use of triple-mechanical devices is required, resulting in increased cost and volume and low substitutability.
Using a filter design that includes two bridges, two fixed frequency bandpass filters and variable frequency hopping filters, the filters of two frequencies are combined through a 3dB bridge to achieve the simultaneous execution of two signals. Filter.
It realizes the flexibility of filtering two frequency signals without adding complex design and debugging work, reducing product volume and cost, and improving design flexibility.
Smart Images
Figure CN222484678U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a filter with two-way filtering functions, belonging to the technical field of filters. Background Art
[0002] In order to realize the merging of two filters and filter two frequency signals at the same time, see the principle block diagram. Figure 5 One of them is a fixed frequency band pass filter, and the other is a variable frequency frequency hopping filter. The operating frequency of the fixed frequency band pass filter is within the operating frequency range of the variable frequency frequency hopping filter.
[0003] See Figure 5 , assuming that the working frequency of the fixed frequency bandpass filter is F1, and the working frequency of the variable frequency hopping filter is F2; the variable frequency hopping filter is a narrowband bandpass filter, and its adjustable frequency range is set to Fa~Fb. Where Fa≤F1≤Fb.
[0004] To filter the two frequencies F1 and F2 simultaneously, the current conventional approach requires the use of a triplexer. Since F1 is within the frequency range of the variable frequency hopping filter, Fa~Fb needs to be implemented using two variable frequency hopping filters. Figure 6 This approach has the following disadvantages:
[0005] 1) The frequency hopping filter of Fa~Fb frequency needs to be implemented with two frequency hopping filters, which increases the cost and volume;
[0006] 2) The triplexer needs to be specially designed and debugged according to the required frequency, and its interchangeability is not high. Summary of the invention
[0007] The technical problem to be solved by the utility model is to provide a filter with two-way filtering functions to solve the problems existing in the above-mentioned prior art.
[0008] The technical solution adopted by the utility model is: a filter with two-way filtering function, including two bridges, two fixed-frequency band-pass filters and a variable-frequency hopping filter, the two fixed-frequency band-pass filters are respectively connected to port 0° and port 90° and port 90° and port 0° of the two bridges, the variable-frequency hopping filter is connected to port ISO of the two bridges, and ports IN of the two bridges are respectively used as signal input terminals and signal output terminals.
[0009] Furthermore, the above-mentioned bridge adopts a 3dB bridge.
[0010] Furthermore, the fixed frequency bandpass filter adopts a bandpass filter with a frequency of 40.5 MHz, and the variable frequency hopping filter adopts a frequency hopping filter with a frequency of 30-90 MHz.
[0011] Beneficial effects of the utility model: Compared with the prior art, the utility model combines the filters of two frequencies through a 3dB bridge, thereby achieving the function of filtering the two signals at the same time, and has the following effects:
[0012] 1) The bridge used only needs to be within the operating frequency range of the frequency hopping filter, and does not require complicated design and debugging;
[0013] 2) More flexibility. If the frequency of the fixed-frequency bandpass filter in the simulation experiment is changed to other frequency points between 30 and 90 MHz, the triplexer needs to be redesigned, but the bridge does not need to be redesigned;
[0014] 3) The use of a triplexer requires the frequency hopping filter to be divided into two frequency bands, which makes the product larger and more expensive. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is the circuit schematic;
[0016] Figure 2 It is a simulation schematic diagram of a filter with two-way filtering function;
[0017] Figure 3 This is a circuit simulation comparison result diagram;
[0018] Figure 4 This is the waveform of a fixed frequency bandpass filter at 40.5MHz;
[0019] Figure 5 This is a circuit schematic for filtering two frequencies simultaneously;
[0020] Figure 6 It is the circuit schematic diagram of a triplexer that processes two frequencies simultaneously. DETAILED DESCRIPTION
[0021] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.
[0022] Example 1: Figure 1 As shown, a filter with two-way filtering function includes two bridges, two fixed frequency bandpass filters and a variable frequency hopping filter. The two fixed frequency bandpass filters are respectively connected to the ports 0° and 90° and the ports 90° and 0° of the two bridges. The variable frequency hopping filter is connected to the port ISO of the two bridges. The ports IN of the two bridges are respectively used as the signal input and signal output ends. Two bandpass filters with an operating frequency of F1 are used and connected to the 0° and 90° ports of the 3dB bridge. The frequency hopping filter is connected to the port ISO of the bridge. In this way, two frequency signals can be filtered at the same time.
[0023] Furthermore, the above-mentioned bridge adopts a 3dB bridge.
[0024] Furthermore, the fixed frequency bandpass filter adopts a bandpass filter with a frequency of 40.5 MHz, and the variable frequency hopping filter adopts a frequency hopping filter with a frequency of 30-90 MHz.
[0025] The utility model can meet the filter index requirements:
[0026] 1. Frequency range: fixed frequency bandpass filter is 40.5MHz, variable frequency hopping filter is 30~90MHz
[0027] 2. Insertion loss: The loss of a single filter is 3dB, and the loss after the bridge combines the two frequencies is ≤4dB
[0028] 3.3dB bandwidth: 3%~5%
[0029] 4. Input and output port impedance: 50Ω
[0030] 5. It can filter the fixed frequency 40.5MHz and the variable frequency 30~90MHz at the same time.
[0031] The simulation schematic diagram used is shown in Figure 2 Set two 40.5MHz bandpass filters with a 3dB bandwidth of 4% and an insertion loss of 3dB; the frequency hopping filter has an operating frequency range of 30 to 90MHz, a 3dB bandwidth of 4%, and an insertion loss of 3dB. Figure 1 Make the connection and see the simulation results. Figure 3 .
[0032] Set the center frequency fx of the frequency hopping filter as a variable and scan it. The simulation results are shown in Figure 4 Among them, M1, M3, M4, and M5 are waveforms of the frequency hopping filter operating at 30MHz, 50MHz, 70MHz, and 90MHz; M2 is the waveform of the fixed frequency bandpass filter 40.5MHz when the frequency hopping filter operates at the above frequencies.
[0033] From the simulation results, we can see that this solution can filter two frequency signals at the same time. Compared with using a triplexer, this solution has the following advantages:
[0034] 1) The bridge used only needs to be within the operating frequency range of the frequency hopping filter, and does not require complicated design and debugging;
[0035] 2) More flexibility. If the frequency of the fixed-frequency bandpass filter in the example is changed to other frequency points between 30 and 90 MHz, the triplexer needs to be redesigned, but the bridge does not;
[0036] 3) The use of a triplexer requires the frequency hopping filter to be divided into two frequency bands, which makes the product larger and more expensive.
[0037] The above description is only a specific implementation method of the present utility model, but the protection scope of the present utility model is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present utility model, which should be included in the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be based on the protection scope of the claims.
Claims
1. A filter with two-way filtering function, characterized in that: It includes two bridges, two fixed frequency band-pass filters and a variable frequency hopping filter. The two fixed frequency band-pass filters are respectively connected to port 0° and port 90° and port 90° and port 0° of the two bridges. The variable frequency hopping filter is connected to port ISO of the two bridges. Port IN of the two bridges serves as a signal input terminal and a signal output terminal respectively.
2. A filter with two-way filtering function according to claim 1, characterized in that: The bridge uses a 3dB bridge.
3. The filter with two-way filtering function according to claim 1, characterized in that: The fixed frequency band pass filter adopts a band pass filter with a frequency of 40.5 MHz, and the variable frequency hopping filter adopts a frequency hopping filter with a frequency of 30 to 90 MHz.