Coupling triplexer circuit and triplexer
By designing coupled triad circuits, including low-pass, band-pass, high-pass filtering circuits and parallel coupling lines, the problem of traditional triad circuits without direct coupling output function and poor rectangular coefficient is solved, which enables easy signal acquisition and detection, and improves rectangular coefficient.
Patent Information
- Application Number
- CN202421698373.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-17
- Publication Date
- 2025-05-16
- Estimated Expiration
- 2034-07-17
AI Technical Summary
The traditional triple-mechanical circuit does not have a direct coupling output function, and the rectangular coefficient is poor, which increases the circuit complexity and number of components.
A coupled triode circuit is designed, including a low-pass filter circuit, a band-pass filter circuit, a high-pass filter circuit and a parallel coupling line, through which the coupled output of the signal is realized.
It realizes direct coupled output, facilitates signal acquisition and detection, and at the same time improves the rectangular coefficient, reduces additional transformation circuits, and reduces design and debugging difficulty.
Smart Images
Figure CN222884649U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of filters, in particular to a coupling triplexer circuit and a triplexer. Background Art
[0002] As a filtering device, the triplexer is widely used in various communication technology fields, such as radar, railway communication, weather detection and satellite communication. It plays the role of channel isolation, harmonic suppression and spurious elimination in the receiving and transmitting units of wireless communication. When the loss is determined, the rectangular coefficient of the traditional triplexer circuit is poor, and adding a zero point requires an additional impedance transformation circuit, which increases the complexity of the circuit and the number of components. In addition, the traditional triplexer does not have the function of direct coupling output, which is not convenient for signal acquisition and detection.
[0003] Therefore, the prior art needs to be improved. Utility Model Content
[0004] In view of this, the utility model provides a coupling triplexer circuit and a triplexer, which are used to solve the problem that the traditional triplexer in the prior art has no direct coupling output function and has a poor rectangular coefficient.
[0005] To achieve one or part or all of the above purposes or other purposes, the utility model proposes a coupled triplexer circuit, including a common port, a first channel port, a second channel port, a third channel port, a coupled port, a low-pass filter circuit, a band-pass filter circuit, a high-pass filter circuit parallel coupled lines, and a load resistor, wherein the parallel coupled lines include a first coupled microstrip line and a second coupled microstrip line; an input end of the low-pass filter circuit is connected to the first channel port, an input end of the band-pass filter circuit is connected to the second channel port, an input end of the high-pass filter circuit is connected to the third channel port, a first end of the first coupled microstrip line is connected to the common port, output ends of the low-pass filter circuit, the band-pass filter circuit, and the high-pass filter circuit are all connected to the second end of the first coupled microstrip line, a first end of the second coupled microstrip line is connected to the coupled port, and a second end of the second coupled microstrip line is grounded through a load resistor.
[0006] Preferably, the parallel coupling lines are in a Z-shape.
[0007] Preferably, the low-pass filter circuit includes a first inductor, a second inductor, a third inductor, a fourth inductor, a fifth inductor and a sixth inductor connected in series in sequence, the first end of the first inductor is connected to the second end of the first coupled microstrip line, and the end of the sixth inductor away from the fifth inductor is connected to the first channel port; the low-pass filter circuit also includes a first capacitor, a second capacitor, a third capacitor, a fourth capacitor and a fifth capacitor, the first ends of the first capacitor, the second capacitor, the third capacitor, the fourth capacitor and the fifth capacitor are respectively connected to the second ends of the first inductor, the second inductor, the third inductor, the fourth inductor and the fifth inductor, and the second ends of the first capacitor, the second capacitor, the third capacitor, the fourth capacitor and the fifth capacitor are all grounded.
[0008] Preferably, the bandpass filter circuit includes a sixth capacitor, a seventh inductor, a seventh capacitor, an eighth inductor, an eighth capacitor, a ninth inductor, a ninth capacitor, a tenth inductor, a tenth capacitor, and an eleventh inductor connected in series in sequence, the first end of the sixth capacitor is connected to the second end of the first coupled microstrip line, the second end of the eleventh inductor is connected to the second channel port, the bandpass filter circuit also includes an eleventh capacitor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor, and a fifteenth capacitor, the first ends of the eleventh capacitor, the twelfth capacitor, the thirteenth capacitor, the fourteenth capacitor, and the fifteenth capacitor are respectively connected to the second ends of the seventh inductor, the eighth inductor, the ninth inductor, the tenth inductor, and the eleventh inductor, and the second ends of the twelfth capacitor, the thirteenth capacitor, the fourteenth capacitor, and the fifteenth capacitor are all grounded.
[0009] Preferably, the bandpass filter circuit further includes a twelfth inductor, the first end of the twelfth capacitor is indirectly connected to the second end of the eighth inductor through the twelfth inductor, the first end of the twelfth inductor is connected to the second end of the eighth inductor, and the second end of the twelfth inductor is connected to the first end of the twelfth inductor.
[0010] Preferably, the bandpass filter circuit further includes a sixteenth capacitor, a first end of the sixteenth capacitor is connected to the first end of the eleventh inductor, and a second end of the sixteenth capacitor is connected to the second end of the eleventh inductor.
[0011] Preferably, the high-pass filter circuit includes a seventeenth capacitor, an eighteenth capacitor, a nineteenth capacitor, a twentieth capacitor, a twenty-first capacitor, a twenty-second capacitor, a twenty-third capacitor, a twenty-fourth capacitor, and a twenty-fifth capacitor connected in series in sequence, a first end of the seventeenth capacitor is connected to the second end of the first coupled microstrip line, a second end of the twenty-fifth capacitor is connected to the third channel port, and the high-pass filter circuit also includes a thirteenth inductor, a fourteenth inductor, a fifteenth inductor, a sixteenth inductor, a seventeenth inductor, an eighteenth inductor, a nineteenth inductor, and a twentieth inductor, and the thirteenth inductor, the fourteenth inductor, the fifteenth inductor, the sixteenth inductor, and the seventeenth inductor are connected in series in sequence. The first ends of the inductor, the eighteenth inductor, the nineteenth inductor and the twentieth inductor are respectively connected to the second ends of the seventeenth capacitor, the eighteenth capacitor, the nineteenth capacitor, the twentieth capacitor, the twenty-first capacitor, the twenty-second capacitor, the twenty-third capacitor and the twenty-fourth capacitor, and the second ends of the thirteenth inductor, the fourteenth inductor, the fifteenth inductor, the sixteenth inductor, the seventeenth inductor, the eighteenth inductor and the nineteenth inductor are all grounded; the high-pass filter circuit also includes a twenty-sixth capacitor, the first end of the twenty-sixth capacitor is connected to the second end of the 20th inductor, and the second end of the twenty-sixth capacitor is grounded.
[0012] Preferably, the load resistor is 50Ω.
[0013] The utility model also provides a triplexer, comprising a printed circuit board, on which the above-mentioned coupling triplexer circuit is arranged.
[0014] Preferably, the dielectric constant of the printed circuit board is 2.2.
[0015] Preferably, the printed circuit board includes a square plate on the left, an E-shaped plate on the right, and a connecting portion in the middle, and the square plate and the E-shaped plate are connected by the connecting portion; the low-pass filter circuit, the band-pass filter circuit, the high-pass filter circuit, the first channel port, the second channel port, and the third channel port are all distributed on the E-shaped plate, and the first channel port, the second channel port, and the third channel port are respectively located at the right ends of the three branches of the E-shaped plate; the common port, the coupling port, and the parallel coupling line are all arranged on the square plate.
[0016] Implementing the embodiments of the present utility model will have the following beneficial effects:
[0017] 1. Able to directly couple the output, convenient for signal acquisition and detection;
[0018] 2. In the preferred embodiment, a zero point is added to improve the rectangular coefficient without adding an additional conversion circuit, and the difficulty of design and debugging is low. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0020] in:
[0021] Figure 1 A circuit diagram of a coupling triplexer circuit according to an embodiment of the utility model;
[0022] Figure 2 This is a schematic diagram of the structure of a printed circuit board in another embodiment of the utility model.
[0023] In the figure: 10, low-pass filter circuit; 20, band-pass filter circuit; 30, high-pass filter circuit; 40, printed circuit board; P1, common port; P2, first channel port; P3, second channel port; P4, third channel port; P5, coupling port; DC, parallel coupling line; R, load resistance; L1, first inductor; L2, second inductor; L3, third inductor; L4, fourth inductor; L5, fifth inductor; L6, sixth inductor; L7, seventh inductor; L8, eighth inductor; L9, ninth inductor; L10, tenth inductor; L11, eleventh inductor; L12, twelfth inductor; L13, thirteenth inductor; L14, fourteenth inductor; L15, fifteenth inductor; L16, sixteenth inductor; L17, seventeenth inductor; L18, eighteenth inductor; L19, the nineteenth inductor; L20, the twentieth inductor; C1, the first capacitor; C2, the second capacitor; C3, the third capacitor; C4, the fourth capacitor; C5, the fifth capacitor; C6, the sixth capacitor; C7, the seventh capacitor; C8, the eighth capacitor; C9, the ninth capacitor C10, the tenth capacitor; C11, the eleventh capacitor; C12, the twelfth capacitor; C13, the thirteenth capacitor; C14, the fourteenth capacitor; C15, the fifteenth capacitor; C16, the sixteenth capacitor; C17, the seventeenth capacitor; C18, the eighteenth capacitor; C19, the nineteenth capacitor; C20, the twentieth capacitor; C21, the twenty-first capacitor; C22, the twenty-second capacitor; C23, the twenty-third capacitor; C24, the twenty-fourth capacitor; C25, the twenty-fifth capacitor; C26, the twenty-sixth capacitor. DETAILED DESCRIPTION
[0024] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.
[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.
[0026] It is understood that the singular forms "a", "an" and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" etc. specify the presence of stated features, wholes, steps, operations, components, parts or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof.
[0027] In addition, the terms "disposed", "provided with", "connected", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a direct connection, an indirect connection through an intermediate medium, or an internal connection between two devices, elements or components. For ordinary technicians in this field, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.
[0028] Reference Figure 1 An embodiment of the utility model provides a coupled triplexer circuit, comprising a common port P1, a first channel port P2, a second channel port P3, a third channel port P4, a coupled port P5, a low-pass filter circuit 10, a band-pass filter circuit 20, a high-pass filter circuit 30, a parallel coupled line DC and a load resistor R, wherein the parallel coupled line DC comprises a first coupled microstrip line and a second coupled microstrip line; an input end of the low-pass filter circuit 10 is connected to the first channel port P2, an input end of the band-pass filter circuit 20 is connected to the second channel port P3, an input end of the high-pass filter circuit 30 is connected to the third channel port P4, a first end of the first coupled microstrip line is connected to the common port P1, output ends of the low-pass filter circuit 10, the band-pass filter circuit 20 and the high-pass filter circuit 30 are all connected to the second end of the first coupled microstrip line, a first end of the second coupled microstrip line is connected to the coupled port P5 for outputting coupled signals of three frequency bands, and a second end of the second coupled microstrip line is grounded through a load resistor R.
[0029] In some optional embodiments, such as Figure 1 As shown, the low-pass filter circuit 10 is a twelfth-order low-pass filter circuit, which is used to select signals with a frequency of 200 MHz to 460 MHz to pass through. The low-pass filter circuit 10 includes a first inductor L1, a second inductor L2, a third inductor L3, a fourth inductor L4, a fifth inductor L5, and a sixth inductor L6 which are connected in series in sequence; the second end of the first inductor L1 is connected to the first end of the second inductor L2, and the first end of the first inductor L1 is connected to the second end of the first coupled microstrip line; the end of the sixth inductor L6 away from the fifth inductor L5, i.e., the second end, is connected to the first channel port P2; the low-pass filter circuit 10 also includes a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, and a fifth capacitor C5, the first ends of the first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5 are respectively connected to the second ends of the first inductor L1, the second inductor L2, the third inductor L3, the fourth inductor L4, and the fifth inductor L5, and the second ends of the first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4, and the fifth capacitor C5 are all grounded.
[0030] In some optional embodiments, such as Figure 1 As shown, the bandpass filter circuit 20 is a fifth-order bandpass filter circuit, which is used to select signals with a frequency of 886MHz to 930MHz to pass through. The bandpass filter circuit 20 includes a sixth capacitor C6, a seventh inductor L7, a seventh capacitor C7, an eighth inductor L8, an eighth capacitor C8, a ninth inductor L9, a ninth capacitor C9, a tenth inductor L10, a tenth capacitor C10, and an eleventh inductor L11 connected in series in sequence, the first end of the sixth capacitor C6 is connected to the second end of the first coupled microstrip line, the second end of the eleventh inductor L11 is connected to the second channel port P3, and the bandpass filter circuit 20 also includes an eleventh capacitor C11, a twelfth capacitor C12, and a thirteenth capacitor C13. , a fourteenth capacitor C14, a fifteenth capacitor C15, the first ends of the eleventh capacitor C11, the twelfth capacitor C12, the thirteenth capacitor C13, the fourteenth capacitor C14, and the fifteenth capacitor C15 are respectively connected to the second ends of the seventh inductor L7, the eighth inductor L8, the ninth inductor L9, the tenth inductor L10, and the eleventh inductor L11, and the second ends of the twelfth capacitor C12, the thirteenth capacitor C13, the fourteenth capacitor C14, and the fifteenth capacitor C15 are all grounded.
[0031] In some optional embodiments, such as Figure 1As shown, the band-pass filter circuit 20 also includes a twelfth inductor L12, the first end of the twelfth capacitor C12 is indirectly connected to the second end of the eighth inductor L8 through the twelfth inductor L12, the first end of the twelfth inductor L12 is connected to the second end of the eighth inductor L8, the second end of the twelfth inductor L12 is connected to the first end of the twelfth inductor L12, and the twelfth inductor L12 is used to add a zero point on the left side of the passband frequency.
[0032] In some optional embodiments, such as Figure 1 As shown, the bandpass filter circuit 20 also includes a sixteenth capacitor C16, a first end of the sixteenth capacitor C16 is connected to the first end of the eleventh inductor L11, and a second end of the sixteenth capacitor C16 is connected to the second end of the eleventh inductor L11, for adding a zero point on the right side of the passband frequency.
[0033] In some optional embodiments, such as Figure 1As shown, the high-pass filter circuit 30 is a seventeen-order high-pass filter circuit, which is used to select signals with a frequency of 1200MHz to 1500MHz to pass through. The high-pass filter circuit 30 includes a seventeenth capacitor C17, an eighteenth capacitor C18, a nineteenth capacitor C19, a twentieth capacitor C20, a twenty-first capacitor C21, a twenty-second capacitor C22, a twenty-third capacitor C23, a twenty-fourth capacitor C24, and a twenty-fifth capacitor C25, which are sequentially connected in series, wherein a first end of the seventeenth capacitor C17 is connected to a second end of the first coupled microstrip line, and a second end of the twenty-fifth capacitor C25 is connected to the third channel port P4; the high-pass filter circuit 30 also includes a thirteenth inductor L13, a fourteenth inductor L14, a fifteenth inductor L15, a sixteenth inductor L16, a seventeenth inductor L17, an eighteenth inductor L18, a nineteenth inductor L19, and a twentieth inductor L20; the thirteenth inductor L13, the fourteenth inductor L14, the fifteenth inductor L15, the sixteenth inductor L16, the seventeenth inductor L17, the eighteenth inductor L 18. The first ends of the nineteenth inductor L19 and the twentieth inductor L20 are respectively connected to the second ends of the seventeenth capacitor C17, the eighteenth capacitor C18, the nineteenth capacitor C19, the twentieth capacitor C20, the twenty-first capacitor C21, the twenty-second capacitor C22, the twenty-third capacitor C23, and the twenty-fourth capacitor C24, and the second ends of the thirteenth inductor L13, the fourteenth inductor L14, the fifteenth inductor L15, the sixteenth inductor L16, the seventeenth inductor L17, the eighteenth inductor L18, and the nineteenth inductor L19 are all grounded; the high-pass filter circuit 30 also includes a twenty-sixth capacitor C26, a first end of the twenty-sixth capacitor C26 is connected to the second end of the 20th inductor L20, a second end of the twenty-sixth capacitor C26 is grounded, and the twenty-sixth capacitor C26 is used to add a zero point on the left side of the passband frequency.
[0034] In some optional embodiments, the load resistor R is 50Ω.
[0035] More preferably, in some optional embodiments, the above-mentioned twenty inductors are all air-core wound inductors.
[0036] More preferably, in some optional embodiments, the above-mentioned twenty-six capacitors are all high-Q ceramic capacitors.
[0037] Another embodiment of the present invention further provides a triplexer, such as Figure 2 As shown, the triplexer includes a printed circuit board 40 , on which the above-mentioned coupling triplexer circuit is arranged.
[0038] In some optional embodiments, the dielectric constant of the printed circuit board 40 is 2.2.
[0039] In some optional embodiments, such as Figure 2 As shown, the printed circuit board 40 includes a square plate on the left, an E-shaped plate on the right and a connecting portion in the middle, and the square plate and the E-shaped plate are connected by the connecting portion; the low-pass filter circuit 10, the band-pass filter circuit 20, the high-pass filter circuit 30, the first channel port P2, the second channel port P3, and the third channel port P4 are all distributed on the E-shaped plate, and the first channel port P2, the second channel port P3, and the third channel port P4 are respectively located at the right ends of the three branches of the E-shaped plate; the common port P1, the coupling port P5, and the parallel coupling line DC are all arranged on the square plate.
[0040] The coupled triplexer circuit and triplexer provided by the embodiments of the present utility model have the following beneficial effects:
[0041] 1. Able to directly couple the output, convenient for signal acquisition and detection;
[0042] 2. In the preferred embodiment, a zero point is added to improve the rectangular coefficient without adding an additional conversion circuit, and the difficulty of design and debugging is low.
[0043] The above disclosure is only a preferred embodiment of the present invention, and certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope covered by the present invention.
Claims
1. A coupled triplexer circuit, characterized in that: It includes a common port, a first channel port, a second channel port, a third channel port, a coupling port, a low-pass filter circuit, a band-pass filter circuit, a high-pass filter circuit, parallel coupling lines and a load resistor, wherein the parallel coupling lines include a first coupling microstrip line and a second coupling microstrip line; the input end of the low-pass filter circuit is connected to the first channel port, the input end of the band-pass filter circuit is connected to the second channel port, the input end of the high-pass filter circuit is connected to the third channel port, the first end of the first coupling microstrip line is connected to the common port, the low-pass filter circuit, the band-pass filter circuit and the output end of the band-pass filter circuit are all connected to the second end of the first coupling microstrip line, the first end of the second coupling microstrip line is connected to the coupling port, and the second end of the second coupling microstrip line is grounded through the load resistor.
2. The coupling triplexer circuit according to claim 1, wherein: The parallel coupling lines are in a zigzag shape.
3. The coupling triplexer circuit according to claim 1, wherein: The low-pass filter circuit includes a first inductor, a second inductor, a third inductor, a fourth inductor, a fifth inductor, and a sixth inductor connected in series in sequence, wherein a first end of the first inductor is connected to a second end of the first coupled microstrip line, and an end of the sixth inductor away from the fifth inductor is connected to the first channel port; the low-pass filter circuit also includes a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, and a fifth capacitor, wherein first ends of the first capacitor, the second capacitor, the third capacitor, the fourth capacitor, and the fifth capacitor are respectively connected to second ends of the first inductor, the second inductor, the third inductor, the fourth inductor, and the fifth inductor, and second ends of the first capacitor, the second capacitor, the third capacitor, the fourth capacitor, and the fifth capacitor are all grounded.
4. The coupling triplexer circuit according to claim 1, wherein: The band-pass filter circuit includes a sixth capacitor, a seventh inductor, a seventh capacitor, an eighth inductor, an eighth capacitor, a ninth inductor, a ninth capacitor, a tenth inductor, a tenth capacitor, and an eleventh inductor connected in series in sequence, a first end of the sixth capacitor is connected to the second end of the first coupled microstrip line, and a second end of the eleventh inductor is connected to the second channel port, the band-pass filter circuit also includes an eleventh capacitor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor, and a fifteenth capacitor, first ends of the eleventh capacitor, the twelfth capacitor, the thirteenth capacitor, the fourteenth capacitor, and the fifteenth capacitor are respectively connected to the second ends of the seventh inductor, the eighth inductor, the ninth inductor, the tenth inductor, and the eleventh inductor, and second ends of the twelfth capacitor, the thirteenth capacitor, the fourteenth capacitor, and the fifteenth capacitor are all grounded.
5. The coupling triplexer circuit according to claim 4, wherein: The bandpass filter circuit also includes a twelfth inductor, a first end of the twelfth capacitor is indirectly connected to the second end of the eighth inductor through the twelfth inductor, a first end of the twelfth inductor is connected to the second end of the eighth inductor, and a second end of the twelfth inductor is connected to the first end of the twelfth inductor.
6. The coupling triplexer circuit according to claim 4 or 5, characterized in that: The bandpass filter circuit further includes a sixteenth capacitor, a first end of the sixteenth capacitor is connected to the first end of the eleventh inductor, and a second end of the sixteenth capacitor is connected to the second end of the eleventh inductor.
7. The coupling triplexer circuit according to claim 1, wherein: The high-pass filter circuit includes a seventeenth capacitor, an eighteenth capacitor, a nineteenth capacitor, a twentieth capacitor, a twenty-first capacitor, a twenty-second capacitor, a twenty-third capacitor, a twenty-fourth capacitor, and a twenty-fifth capacitor connected in series in sequence, a first end of the seventeenth capacitor is connected to the second end of the first coupled microstrip line, and a second end of the twenty-fifth capacitor is connected to the third channel port, and the high-pass filter circuit also includes a thirteenth inductor, a fourteenth inductor, a fifteenth inductor, a sixteenth inductor, a seventeenth inductor, an eighteenth inductor, a nineteenth inductor, and a twentieth inductor, and the thirteenth inductor, the fourteenth inductor, the fifteenth inductor, the sixteenth inductor, the seventeenth inductor, and the The first ends of the eighteenth inductor, the nineteenth inductor and the twenty-th inductor are respectively connected to the second ends of the seventeenth capacitor, the eighteenth capacitor, the nineteenth capacitor, the twenty-th capacitor, the twenty-first capacitor, the twenty-second capacitor, the twenty-third capacitor and the twenty-fourth capacitor, and the second ends of the thirteenth inductor, the fourteenth inductor, the fifteenth inductor, the sixteenth inductor, the seventeenth inductor, the eighteenth inductor and the nineteenth inductor are all grounded; the high-pass filter circuit also includes a twenty-sixth capacitor, the first end of the twenty-sixth capacitor is connected to the second end of the 20th inductor, and the second end of the twenty-sixth capacitor is grounded.
8. The coupling triplexer circuit according to claim 1 or 2, characterized in that: The load resistance is 50Ω.
9. A triplexer, characterized in that: It comprises a printed circuit board, on which the coupling triplexer circuit according to any one of claims 1 to 8 is arranged.
10. The triplexer according to claim 9, wherein: The dielectric constant of the printed circuit board is 2.2.