Integrated intermediate frequency band-pass filter

Abstract

The utility model relates to an integrated medium-frequency band-pass filter which comprises a shell and a filter body, a channel selector is arranged on the left side in the shell, a lifting circuit device is arranged above the channel selector, the filter body is arranged on the right side of the lifting circuit device, and a dynamic noise suppressor is arranged on the right side of the filter body. A group of automatic adjustable dynamic heat dissipation devices are symmetrically arranged on the two sides of the upper part in the shell; the utility model has the advantages of reasonable structure, reduced number of components, dynamic heat dissipation adjustment, miniaturized integrated structure, low cost and easy processing.

Description

Technical Field

[0001] This utility model belongs to the field of filter technology, specifically relating to an integrated intermediate frequency bandpass filter. Background Technology

[0002] Intermediate frequency (IF) filters are mainly used in digital receivers. Their main function is to filter out interference signals such as local oscillator signals, mixing interference frequencies, and image frequency signals in multi-conversion schemes, thereby achieving IF signal spectrum shaping. While maintaining passband width, they also protect receiver circuitry from spurious interference that could cause saturation or distortion in subsequent devices. Their performance is crucial to receiver performance. Traditional bandpass filters suffer from high cost, complexity, difficulty in fabrication, and numerous parasitic parameters. Furthermore, with the rapid development of integrated circuits, bandpass filters are increasingly integrating components and circuit structures to better adapt to the miniaturization and integration requirements of modern wireless communication. This generates significant heat during operation, and existing heat dissipation structures are insufficient for the heat dissipation needs of more integrated bandpass filters, leading to decreased efficiency and quality, and even damage to internal components. Therefore, it is essential to provide an integrated IF bandpass filter with a reasonable structure, reduced component count, dynamic heat dissipation adjustment, miniaturized integrated structure, low cost, and ease of fabrication. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide an integrated intermediate frequency bandpass filter with a reasonable structure, reduced number of components, dynamic heat dissipation adjustment, miniaturized integrated structure, low cost and easy processing.

[0004] The purpose of this utility model is achieved as follows: an integrated intermediate frequency bandpass filter, comprising a housing and a filter body, wherein a channel selector is disposed on the left side inside the housing, a lift circuit is disposed above the channel selector, the filter body is disposed on the right side of the lift circuit, and a dynamic noise suppressor is disposed on the right side of the filter body; and a set of automatically adjustable dynamic heat dissipation devices are symmetrically disposed on both sides of the upper part inside the housing.

[0005] Wiring terminals are provided on both upper sides of the outer shell, and input and output interfaces are provided on both lower sides of the outer shell. Heat dissipation grilles are provided on the outer shell below the input and output interfaces. A set of matching cooling fans is symmetrically arranged on the top of the shell, and the matching cooling fans are dynamically connected to the corresponding automatic adjustable dynamic heat dissipation devices.

[0006] The channel selector is connected to the input interface and the lift circuit via an input line on one side, and to the filter body via an output line on the other side. The filter body is connected to the lift circuit and the dynamic noise suppressor, and the dynamic noise suppressor is connected to the output interface.

[0007] The automatic adjustable dynamic heat dissipation device includes a perforated base plate, which is connected to the inner top wall of the housing via a fixed plate. A dynamic plate is provided above the perforated base plate, and the dynamic plate and the perforated base plate form a certain angle. The connection between the dynamic plate and the perforated base plate is opened and closed by a movable connecting device.

[0008] The dynamic plate has through holes inside, and the through holes are connected to the perforated base plate through flexible heat dissipation corrugated pipes. The perforated base plate has a base on one side opposite to the fixed plate, and a curved toothed rack is installed on the base.

[0009] A limit plate is provided on the top of the dynamic plate near the curved rack. A driver is provided in front of the limit plate. A rectangular opening is provided on the left side of the limit plate for the curved rack to pass through and move. A small gear that meshes with the curved rack is provided inside the rectangular opening. The small gear is poweredly connected to the driver.

[0010] The filter body contains a main circuit board, which is a fourth-order bandpass filter circuit board, consisting of a second-order low-pass filter circuit and a second-order high-pass filter circuit.

[0011] The second-order low-pass filter circuit adopts a VCVS type second-order low-pass filter circuit, and the second-order high-pass filter circuit adopts a VCVS type second-order high-pass filter circuit.

[0012] The beneficial effects of this utility model are as follows: This utility model is an integrated intermediate frequency bandpass filter. During use, in standby or low-speed operation, heat dissipation is achieved through a heat dissipation grille and heat dissipation holes on both sides of the filter body. In high-speed operation, due to the large amount of heat dissipation, in addition to heat dissipation through the heat dissipation grille and heat dissipation holes on both sides of the filter body, an automatic adjustable dynamic heat dissipation device is activated and dynamically engages with a matching cooling fan. The matching cooling fan quickly removes the heat accumulated inside the housing and the heat dissipated by the filter body from the outside of the housing, achieving dynamic heat dissipation adjustment. It can meet different heat dissipation needs according to actual conditions, ensuring that the device can operate stably and reliably. This utility model uses a channel selector to form a channel that can pass through a specific frequency range. The signal to be filtered after passing through the input interface is frequency selected and input into the filter body, and the filtered and noise-reduced signal is output through the output interface. This utility model has the advantages of reasonable structure, reduced number of components, dynamic heat dissipation adjustment, miniaturized integrated structure, low cost and easy processing. Attached Figure Description

[0013] Figure 1 This is a front view of the integrated intermediate frequency bandpass filter of this utility model.

[0014] Figure 2 This is a schematic diagram of the housing of the integrated intermediate frequency bandpass filter of this utility model.

[0015] Figure 3 This is a schematic diagram of the channel selector of the integrated intermediate frequency bandpass filter of this utility model.

[0016] Figure 4 This is a schematic diagram of the internal structure of the integrated intermediate frequency bandpass filter of this utility model.

[0017] Figure 5 This is a schematic diagram of the structure of the automatically adjustable dynamic heat dissipation device for the integrated intermediate frequency bandpass filter of this utility model.

[0018] Figure 6 This is a circuit diagram of the integrated intermediate frequency bandpass filter of this utility model.

[0019] Figure 7 This is a bias circuit diagram of the lift circuit of the integrated intermediate frequency bandpass filter of this utility model.

[0020] Figure 8 This is a circuit diagram of the dynamic noise suppressor of the integrated intermediate frequency bandpass filter of this utility model.

[0021] In the diagram: 1. Housing; 2. Terminal block; 3. Input interface; 4. Output interface; 5. Channel selector; 51. Input line; 52. Output line; 6. Lifting circuit; 7. Filter body; 71. Main circuit board; 8. Dynamic noise suppressor; 9. Automatically adjustable dynamic heat dissipation device; 91. Perforated base plate; 92. Fixing plate; 93. Dynamic plate; 94. Through hole; 95. Movable connecting device; 96. Flexible heat dissipation corrugated pipe; 97. Base; 98. Curved rack; 99. Limiting plate; 901. Driver; 902. Rectangular opening; 903. Pinion; 10. Matching cooling fan; 11. Heat dissipation grille. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings. Example 1

[0023] like Figure 1-5As shown, the integrated intermediate frequency bandpass filter includes a housing 1 and a filter body 7. A channel selector 5 is arranged on the left side inside the housing 1, a lift circuit 6 is arranged above the channel selector 5, the filter body 7 is arranged on the right side of the lift circuit 6, and a dynamic noise suppressor 8 is arranged on the right side of the filter body 7. A set of automatically adjustable dynamic heat dissipation devices 9 are symmetrically arranged on both sides of the upper part inside the housing 1.

[0024] Wiring terminals 2 are provided on both upper sides of the outer side of the housing 1. Input interface 3 and output interface 4 are provided on both lower sides of the outer side of the housing 1. Heat dissipation grilles 11 are provided on the outer side of the housing 1 at the lower positions of the input interface 3 and output interface 4. A set of matching cooling fans 10 are symmetrically arranged on the top of the housing 1. The matching cooling fans 10 are dynamically connected to the corresponding automatic adjustable dynamic heat dissipation devices 9.

[0025] The channel selector 5 is connected to the input interface 3 and the lift circuit 6 via the input line 51 on one side. The channel selector 5 is connected to the filter body 7 via the output line 52 on the other side. The filter body 7 is connected to the lift circuit 6 and the dynamic noise suppressor 8. The dynamic noise suppressor 8 is connected to the output interface 4.

[0026] The automatic adjustable dynamic heat dissipation device 9 includes a perforated bottom plate 91, which is connected to the inner top wall of the housing 1 via a fixed plate 92. A dynamic plate 93 is provided above the perforated bottom plate 91, and the dynamic plate 93 and the perforated bottom plate 91 form a certain angle. The connection between the dynamic plate 93 and the perforated bottom plate 91 is opened and closed by a movable connecting device 95.

[0027] The dynamic plate 93 has a through hole 94 inside. The through hole 94 is connected to the perforated base plate 91 through a flexible heat dissipation corrugated pipe 96. The perforated base plate 91 has a base 97 on one side relative to the fixed plate 92. A curved rack 98 is installed on the top of the base 97.

[0028] A limiting plate 99 is provided on the top of the dynamic plate 93 near the curved rack 98. A driver 901 is provided in front of the limiting plate 99. A rectangular opening 902 is provided on the left side of the limiting plate 99 for the curved rack 98 to pass through and move. A small gear 903 that meshes with the curved rack 98 is provided inside the rectangular opening 902. The small gear 903 is poweredly connected to the driver 901.

[0029] In this embodiment, the working principle of the automatic adjustable dynamic heat dissipation device is as follows: The driver is activated, which drives the pinion to rotate. Since the pinion meshes with the curved rack, the driver can move the pinion along the curved rack, thereby driving the dynamic plate to move. Because the dynamic plate is connected to the perforated base plate via a movable connection (in actual use, hinges, pivots, rotating shafts, etc. can be used), the dynamic plate can open and close relative to the perforated base plate, thereby achieving dynamic interlocking connection between the through-hole of the dynamic plate and the matching cooling fan (in actual use, magnetic attraction, snap-fit ​​structures, interlocking structures, etc., which are separable and connectable, can be used). Rapid heat dissipation is achieved through the matching cooling fan, through-hole, flexible heat dissipation corrugated pipe, and perforated base plate.

[0030] This utility model is an integrated intermediate frequency bandpass filter. In standby or low-speed operation, heat dissipation is achieved through the heat dissipation grille 11 and the heat dissipation holes on both sides of the filter body 7. In high-speed operation, due to the large amount of heat dissipation, in addition to the heat dissipation through the heat dissipation grille 11 and the heat dissipation holes on both sides of the filter body 7, an automatic adjustable dynamic heat dissipation device 9 is activated and dynamically engages with the matching cooling fan 10. The matching cooling fan 10 quickly removes the heat accumulated inside the housing 1 and the heat dissipated by the filter body 7 from the outside of the housing 1, realizing dynamic heat dissipation adjustment. It can meet different heat dissipation requirements according to actual conditions, ensuring that the device can operate stably and reliably. This utility model uses a channel selector 5 to form a channel that can pass through a specific frequency range. The signal to be filtered after passing through the input interface 3 is frequency selected and input into the filter body 7, and the filtered and noise-reduced signal is output through the output interface 4. This utility model has the advantages of reasonable structure, reduced number of components, dynamic heat dissipation adjustment, miniaturized integrated structure, low cost and easy processing. Example 2

[0031] like Figure 6-8 As shown, the integrated intermediate frequency bandpass filter includes a housing 1 and a filter body 7. A channel selector 5 is arranged on the left side inside the housing 1, a lift circuit 6 is arranged above the channel selector 5, the filter body 7 is arranged on the right side of the lift circuit 6, and a dynamic noise suppressor 8 is arranged on the right side of the filter body 7. A set of automatically adjustable dynamic heat dissipation devices 9 are symmetrically arranged on both sides of the upper part inside the housing 1.

[0032] In this embodiment, as Figure 7As shown, the bias circuit is essentially an adder. Its principle is to add a bias to the input signal, raising the measured signal to within the power supply midpoint range, providing a stable DC operating point, avoiding DC operating point deviation, and preventing output signal distortion or saturation. By adjusting the bias voltage, it ensures operation in the linear amplification region while adapting to the dynamic range of signal processing. Furthermore, the bias circuit can be combined with a high-pass filter (such as a coupling capacitor) to isolate unwanted DC, retaining only the AC component. A stable bias voltage reduces the impact of power supply noise or temperature changes on the operating point. The bias circuit can balance the common-mode voltage at the input, and in conjunction with a dynamic noise suppressor, reduce the impact of common-mode noise on the output, improving anti-interference capability. If further amplification of the input signal is required based on the bias, the resistor value can be adjusted appropriately.

[0033] The filter body 7 has a main circuit board 71 inside. The main circuit board 71 is a fourth-order bandpass filter circuit board, which consists of a second-order low-pass filter circuit and a second-order high-pass filter circuit.

[0034] In this embodiment, as Figure 6 As shown, this utility model uses a high-pass filter cascaded with a low-pass filter to form a bandpass filter. The high-pass filter is placed before the low-pass filter so that the low-pass filter can filter out the noise generated by the high-pass filter. For the low-pass filter, the capacitor is generally selected as 1000pF, and for the high-pass filter, the capacitor is generally selected as 0.1uF. Then, the resistance value combined with the capacitor is calculated according to the formula R=1 / 2πfc, thus obtaining the bandpass filter. Figure 6 R2, R6, and R7; To eliminate the error caused by the offset current of the op-amp, the DC resistance to ground of the non-inverting input and the inverting input of the op-amp should be approximately equal. At the same time, the order and gain of the Butterworth filter are related (see Table 1). Based on these two conditions, two equations can be listed: 30 = R4 * R5 / (R4 + R5), R5 = R4 (A-1), 36 = R8 * R9 / (R8 + R9), R8 = R9 (A-1). From this, R4, R5, R8, and R9 can be solved. The principle is to slightly adjust the resistance values ​​according to the actual situation and keep them within a certain limit. Do not make too large a difference. Note that the frequency should not exceed the rated frequency of the op-amp.

[0035] Table 1. Relationship between the order and gain of Butterworth low-pass and high-pass circuits.

[0036] order 2 4 6 8 Gain (A) Level 1 1.586 1.152 1.068 1.038 Level 2 2.235 1.586 1.337 Level 3 2.483 1.889 Level 4 2.610

[0037] The second-order low-pass filter circuit adopts a VCVS type second-order low-pass filter circuit, and the second-order high-pass filter circuit adopts a VCVS type second-order high-pass filter circuit.

[0038] In this embodiment, to meet the requirement of 0dB passband gain and 20Hz~20kHz 3dB cutoff frequency, the fourth-order bandpass filter circuit board consists of a VCVS second-order low-pass filter and a VCVS second-order high-pass filter. The second-order low-pass filter determines the upper limit 3dB cutoff frequency as 20kHz, and the second-order high-pass filter determines the lower limit 3dB cutoff frequency as 20Hz.

[0039] In this embodiment, the circuit diagram of the dynamic noise suppressor is as follows: Figure 8 As shown, the input signal is split into two paths. One path goes through R3 and C6 to the output terminal. V2 is a junction field-effect transistor, which is used as a voltage-controlled resistor in the circuit. Its source voltage is determined by the voltage division ratio of R5 and R6. C5 is a bypass capacitor. W2 is used to adjust the gate voltage of V2 so that it is slightly reverse biased when there is no signal input. At this time, its source-drain resistance is about 100Ω, which is a small resistance value. Therefore, it provides an AC path for C4 to go through the drain and source of V2 and through C5 to ground. Thus, C4 and R3 together form a simple RC high-frequency filter to attenuate the noise (mainly in the high-frequency range) in the output signal flowing to C6.

[0040] Another input signal is input to the base of V1 via C1, operating in common-emitter amplification mode, with the static bias determined by R1; R2 is the collector load resistor of V1, and W1 is the emitter resistor of V1, used to change the negative feedback of the amplifier and control the gain; the output of V1 is sent to the rectifier circuit composed of D1 and D2 via C2, and the rectified output is connected to the gate of V2, and its output voltage controls the magnitude of the channel impedance of the high-frequency filter circuit.

[0041] When a weak signal is input, the rectifier circuit output is very small and has no effect on V2. The noise of the input signal is filtered out by the C4 and R3 network. When the input signal level increases, the rectified output increases, causing the gate potential of V2 to drop. This blocks the C4 and R3 filtering channel, reducing the attenuation of noise and high-frequency components. If the rectified output is large, V2 will be cut off, the filtering channel will be completely cut off, and the output signal will not be affected by the filtering circuit. In short, the noise suppression circuit has no effect on low and mid-frequency signals and high-level high-frequency signals, but only attenuates the high-frequency components of weak signals to a certain extent while suppressing noise.

[0042] C3 is a filter capacitor used to stabilize the output voltage of the rectifier circuit and prevent the gate of V2 from dropping suddenly due to pulses, causing signal distortion. The capacitance of C3 should not be too large, otherwise the voltage on it will not keep up with the changes in the input signal level. C1 and C2 are coupling capacitors. In order to improve the response speed of the amplifier to high-frequency signals, their capacitance is small. The operating level of the noise control circuit is controlled by W1. When its arm is at the upper end, the operating level reaches the minimum value.

[0043] This utility model is an integrated intermediate frequency bandpass filter. In standby or low-speed operation, heat dissipation is achieved through the heat dissipation grille 11 and the heat dissipation holes on both sides of the filter body 7. In high-speed operation, due to the large amount of heat dissipation, in addition to the heat dissipation through the heat dissipation grille 11 and the heat dissipation holes on both sides of the filter body 7, an automatic adjustable dynamic heat dissipation device 9 is activated and dynamically engages with the matching cooling fan 10. The matching cooling fan 10 quickly removes the heat accumulated inside the housing 1 and the heat dissipated by the filter body 7 from the outside of the housing 1, realizing dynamic heat dissipation adjustment. It can meet different heat dissipation requirements according to actual conditions, ensuring that the device can operate stably and reliably. This utility model uses a channel selector 5 to form a channel that can pass through a specific frequency range. The signal to be filtered after passing through the input interface 3 is frequency selected and input into the filter body 7, and the filtered and noise-reduced signal is output through the output interface 4. This utility model has the advantages of reasonable structure, reduced number of components, dynamic heat dissipation adjustment, miniaturized integrated structure, low cost and easy processing.

Claims

1. An integrated intermediate frequency bandpass filter, comprising a housing and a filter body, characterized in that: A channel selector is located on the left side inside the housing. A lifting circuit is located above the channel selector. A filter body is located to the right of the lifting circuit. A dynamic noise suppressor is located to the right of the filter body. A set of automatically adjustable dynamic heat dissipation devices is symmetrically arranged on both sides of the upper part inside the housing.

2. The integrated intermediate frequency bandpass filter according to claim 1, characterized in that: Wiring terminals are provided on both upper sides of the outer shell, and input and output interfaces are provided on both lower sides of the outer shell. Heat dissipation grilles are provided on the outer shell below the input and output interfaces. A set of matching cooling fans is symmetrically arranged on the top of the shell, and the matching cooling fans are dynamically connected to the corresponding automatic adjustable dynamic heat dissipation devices.

3. The integrated intermediate frequency bandpass filter according to claim 2, characterized in that: The channel selector is connected to the input interface and the lift circuit via an input line on one side, and to the filter body via an output line on the other side. The filter body is connected to the lift circuit and the dynamic noise suppressor, and the dynamic noise suppressor is connected to the output interface.

4. The integrated intermediate frequency bandpass filter according to claim 2, characterized in that: The automatic adjustable dynamic heat dissipation device includes a perforated base plate, which is connected to the inner top wall of the housing via a fixed plate. A dynamic plate is provided above the perforated base plate, and the dynamic plate forms an angle with the perforated base plate. The connection between the dynamic plate and the perforated base plate is opened and closed by a movable connecting device.

5. The integrated intermediate frequency bandpass filter according to claim 4, characterized in that: The dynamic plate has through holes inside, and the through holes are connected to the perforated base plate through flexible heat dissipation corrugated pipes. The perforated base plate has a base on one side opposite to the fixed plate, and a curved toothed rack is installed on the base.

6. The integrated intermediate frequency bandpass filter according to claim 5, characterized in that: A limit plate is provided on the top of the dynamic plate near the curved rack. A driver is provided in front of the limit plate. A rectangular opening is provided on the left side of the limit plate for the curved rack to pass through and move. A small gear that meshes with the curved rack is provided inside the rectangular opening. The small gear is poweredly connected to the driver.

7. The integrated intermediate frequency bandpass filter according to claim 3, characterized in that: The filter body contains a main circuit board, which is a fourth-order bandpass filter circuit board, consisting of a second-order low-pass filter circuit and a second-order high-pass filter circuit.

8. The integrated intermediate frequency bandpass filter according to claim 7, characterized in that: The second-order low-pass filter circuit adopts a VCVS type second-order low-pass filter circuit, and the second-order high-pass filter circuit adopts a VCVS type second-order high-pass filter circuit.

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