CN104577268A - Planar lowpass-bandpass triplexer - Google Patents

Abstract

The invention discloses a planar low-pass band-pass triplexer, comprising a low-pass filter (11), two band-pass filters (12), (13) and a transmission line (14), wherein the low-pass filter (11) The two stub-loaded resonators in the two frequencies are respectively the transmission zeros of the center frequencies of the band-pass filter (12) and (13), so that the two band-pass filters at the input of the low-pass filter (11) The center frequency signal of the filter is a short-circuit state; the transmission line (14) is provided with anchor points p1, p2, p3, wherein the distance from p1 to p3, and the distance from p2 to p3 correspond to a quarter wavelength of the center frequency of the bandpass filter respectively, according to Quarter-wavelength impedance inversion, the center frequency signal of band-pass filter (12) and (13) is respectively open-circuit state at p1, p2, and this triplexer is convenient to independently design each low-pass band-pass filter, makes its mutual No impact, can shorten the design cycle and improve design efficiency.

Description

Planar low pass band pass triplexer

technical field

The invention relates to the technical field of planar filters, in particular to a planar low-pass band-pass triplexer.

Background technique

In recent years, with the rapid development of wireless communication technology, people's demand for wireless communication services is increasing day by day. In order to meet people's various needs, the communication system must be compatible with multiple communication standards when designing. Today's wireless communication systems are basically multiplexing systems. For time division multiplexing, the problem can be solved as long as the receiving and transmitting are arranged in different time slices. For frequency division multiplexing, in order to reduce the number of filter devices, the It is necessary to design a special device to isolate different signals without causing interference with each other. Such a device is a multiplexer.

At present, the design of multiplexers composed of band-pass filters is relatively mature, but there are not many design methods for multiplexers composed of low-pass filters and band-pass filters, and each filter can be independently designed. There are very few methods that can be easily combined together. Because the microstrip structure is easy to process and design, low cost, performance meets the actual requirements, and is a planar structure, it is easy to integrate with other components, so the design of an excellent planar low-pass-bandpass multiplexer is a research hotspot in recent years.

In 1999, M.H.Capstisk published a paper titled "Microstrip lowpass-bandpass diplexer topology" on "IEEE Electronic Letter". The structure is shown in Figure 1 below. It simply connects a low-pass filter with a band-pass filter , to form a low-pass-band-pass duplexer, the article is not detailed, it is difficult to achieve independent design of low-pass band-pass filter.

In 2013, Pu-Hua Deng et al. published a paper entitled "Design of Microstrip Lowpass-Bandpass Diplexer" on "IEEE MICROWAVE AND WIRELESS COMPONENTSLETTERS". The structure is shown in Figure 2 below. The low-pass filter and the bandpass filter pass through A quarter-wavelength converter is connected to form a low-pass-band-pass duplexer. Although its low-pass band-pass filter can be designed independently, this structure cannot be applied to the design of a low-pass-band-pass triplexer, and Its low-pass filter performance needs to be improved.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art, and to provide a planar low-pass band-pass triplexer, which is designed to improve the branch of the input end of the low-pass filter from a traditional uniform impedance branch to a branch loaded by an open circuit branch , producing two transmission zeros respectively corresponding to the center frequencies of the two band-pass filters, so the center frequency signals corresponding to the two band-pass filters at the input of the low-pass filter are both short-circuited, and according to the quarter-wavelength impedance Inverted, a quarter of the wavelength corresponding to the center frequency of the input end of the low-pass filter is an open circuit state. Therefore, if a band-pass filter is connected to these two places respectively, the three filters can be designed independently without affect each other.

The object of the present invention is achieved through the following technical solutions:

A planar low-pass band-pass triplexer, which is manufactured on a dielectric substrate in the form of a printed circuit board, and an input terminal feeder port1 and a low-pass filter 11 for inputting electromagnetic wave signals are respectively manufactured on the same surface of the dielectric substrate And its output end feeder head port2 for outputting electromagnetic wave signals, the first bandpass filter 12 working in frequency band 1 and its output end feeder head port3 for outputting electromagnetic wave signals, and the second bandpass filter working in frequency band 2 Device 13 and its output terminal feeder head port4 and transmission line (14) for outputting electromagnetic wave signals, and the other side of the dielectric substrate is a grounding plate;

The first end of the transmission line 14 is connected to the input feeder head port1, and its second end is connected to the low-pass filter 11; the first band-pass filter 12 and the second band-pass filter 13 are respectively Located on both sides of the transmission line 14;

The transmission line 14 is provided with positioning points p1, p2, p3, wherein the positioning point p3 is located at the second end of the transmission line 14, the distance from the positioning point p1 to the positioning point p3, the distance from the positioning point p2 to the The distance between the positioning point p3 corresponds to a quarter wavelength of the center frequency of the first band-pass filter 12 and the second band-pass filter 13 respectively;

The anchor point p1 is used to define the horizontal distance from the first bandpass filter 12 to the anchor point p3, and the anchor point p2 is used to define the second bandpass filter 13 to the anchor point p3 horizontal distance.

Further, the low-pass filter 11 includes six resonators, an input feeder 110 and an output feeder 1110, the input feeder 110 is a part of the transmission line 14, and the first end of the input feeder 110 corresponds to the The second end of the transmission line 14;

The first resonator of the low-pass filter 11 includes a transmission line 1111 and a transmission line 1121, the two are vertically connected to form a stub-loaded resonator; the second resonator of the low-pass filter 11 includes a transmission line 1112 and a transmission line 1122, both The vertical connection constitutes a stub-loaded resonator, and the first end of the transmission line 1111 and the first end of the transmission line 1112 are connected in a straight line and then vertically connected to the first end of the input feeder 110;

The third resonator of the low-pass filter 11 includes a transmission line 1141 and a transmission line 1151, the two are vertically connected to form a step impedance resonator; the fourth resonator of the low-pass filter 11 includes a transmission line 1142 and a transmission line 1152, two Or vertically connected to form a step impedance resonator;

The fifth resonator of the low-pass filter 11 includes a transmission line 1171; the sixth resonator of the low-pass filter 11 includes a transmission line 1172, and the first end of the transmission line 1171 and the first end of the transmission line 1172 are connected in a straight line, respectively vertically connected to the first end of the output feeder 1110;

The low-pass filter 11 also includes a high-impedance transmission line 113 and a high-impedance transmission line 116, which are used to connect the six resonators of the low-pass filter 11 to each other, and the high-impedance transmission line 113 and the high-impedance transmission line 116 are connected in a straight line The first, third and fifth resonators and the second, fourth and sixth resonators of the low-pass filter 11 have a symmetrical structure with the high-impedance transmission line 113 and the high-impedance transmission line 116 as the center line.

Further, the length of the transmission line from the second end of the transmission line 1111 and the transmission line 1112 to the first end of the input feeder 110 corresponds to a quarter wavelength corresponding to the center frequency of the first bandpass filter 12, and the transmission line 1121 And the length of the transmission line from the second end of the transmission line 1122 to the first end of the input feeder 110 corresponds to a quarter wavelength corresponding to the center frequency of the second bandpass filter 13 .

Further, two first rectangular slits 118 and second rectangular slits 119 of the same size are etched on the corresponding dielectric substrate directly below the high-impedance transmission line 113 and the high-impedance transmission line 116 .

Further, the first bandpass filter 12 includes an input feeder 120, an output feeder 127 and four resonators, wherein one end of the first resonator 121 and the fourth resonator 126 of the first bandpass filter 12 is an open circuit, and the other end is a short circuit, and the short circuit end is provided with a grounding via hole, and the resonator lengths of the first resonator 121 and the fourth resonator 126 are four times corresponding to the center frequency of the first bandpass filter 12. one-half wavelength;

Wherein the second resonator 122 and the third resonator 124 of the first bandpass filter 12 are U-shaped step impedance resonators, and the second resonator 122 and the third resonator 124 of the U-shaped step impedance Both ends are open circuits, and the centers of the two are respectively connected with a loaded transmission line stub 123 and a loaded transmission line stub 125 of different lengths, and the resonant frequency of the second resonator 122 and the third resonator 124 is the same as that of the first band The center frequency of the pass filter 12.

Further, the input feeder 120 corresponds to the section from the first end of the transmission line 14 to the positioning point p1;

The first resonator 121 of the first bandpass filter 12 includes a left transmission line 1211, a middle transmission line 1212 and a right transmission line 1213, wherein the middle transmission line 1212 is adjacent to and parallel to the input feeder line 120, and the middle Two ends of the transmission line 1212 are vertically connected to the left transmission line 1211 and the right transmission line 1213 respectively, and the right transmission line 1213 is located on a straight line with the positioning point p1.

Further, the second bandpass filter 13 includes an input feeder 130, an output feeder 135 and four resonators, and the resonator lengths of the above resonators are two times corresponding to the center frequency of the second bandpass filter 13. One-half wavelength, wherein both ends of the first resonator 131 and the fourth resonator 134 of the second bandpass filter 13 are open circuits;

The second resonator 132 and the third resonator 133 of the second bandpass filter 13 are U-shaped resonators, and both ends of the U-shaped second resonator 132 and the third resonator 133 are open circuits.

Further, the input feeder 130 corresponds to the section from the first end of the transmission line 14 to the positioning point p2;

The first resonator 131 of the second bandpass filter 13 includes a middle transmission line 1311 and a right side transmission line 1312, wherein the middle transmission line 1311 is adjacent to and parallel to the input feeder line 130, and one end of the middle transmission line 1311 is connected to The right transmission line 1312 is vertically connected, and the right transmission line 1312 is located on a straight line with the positioning point p2.

Further, the input feed or output feed of the first band-pass filter 12 , the second band-pass filter 13 and the low-pass filter 11 adopts tap feed or coupled feed.

Further, the transmission line adopts a microstrip line, and is in the form of a straight line or a broken line.

Compared with the prior art, the present invention has the following advantages and effects:

1) The present invention adopts the step impedance stub as the resonator, and the transmission zero point generated by it can be controlled more freely without affecting the passband performance of the low-pass filter, thereby improving the selectivity of the low-pass filter. At the same time, one end of the low-pass filter uses a stub-loaded resonator, and the other end uses a uniform impedance stub as a resonator, which can generate multiple transmission zeros. On the one hand, it can expand the stopband bandwidth of the low-pass filter, and on the other hand, it can enhance the low-pass filter. stop-band suppression of the device.

2) The present invention adopts unique stub-loaded resonator structure because the end of the low-pass filter is close to the band-pass filter, and the generation frequency corresponds to the transmission zero point of the center frequency of the two band-pass filters respectively, so that the band-pass filter and When the low-pass filter is connected according to a quarter-wavelength distance, the performance of the band-pass filter will not be affected, so that each low-pass band-pass filter can be independently designed, and finally simply connected, greatly reducing the three The design difficulty of the tool.

3) The structure of the low-pass band-pass triplexer disclosed in the present invention has the advantages of low insertion loss and high selectivity.

4) The low-pass and band-pass triplexer disclosed in the present invention can be realized with a microstrip structure, is light in weight, low in cost, and suitable for industrial mass production. Therefore, the triplexer has the advantages of simple structure, easy design, and low manufacturing cost.

Description of drawings

FIG. 1 is a schematic structural diagram of a duplexer disclosed in prior art 1;

FIG. 2 is a schematic structural diagram of a duplexer disclosed in prior art 2;

Fig. 3 is the overall structure schematic diagram of the planar low-pass band-pass triplexer that the present invention proposes;

Fig. 4 is the structural representation of the low-pass filter in the planar low-pass band-pass triplexer that the present invention proposes;

Fig. 5 is the structural representation of the first band-pass filter in the planar low-pass band-pass triplexer that the present invention proposes;

Fig. 6 is the structural representation of the second band-pass filter in the planar low-pass band-pass triplexer that the present invention proposes;

Fig. 7 is the simulation diagram of the straight-through effect of the planar low-pass band-pass triplexer proposed by the present invention;

Fig. 8 is a simulation diagram of the isolation effect of the planar low-pass band-pass triplexer proposed by the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention more clear and definite, the present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Example

Please refer to FIG. 3 . FIG. 3 is a schematic diagram of the overall structure of the planar low-pass band-pass triplexer disclosed in the embodiment of the present invention. The planar low-pass band-pass triplexer as shown in the figure is fabricated on a dielectric substrate in the form of a printed circuit board. On the same surface of the dielectric substrate, an input end feeder port1 for inputting electromagnetic wave signals, a low The pass filter 11 and the low pass filter 11 are used to output the output terminal feeder port2 of the electromagnetic wave signal, a first band pass filter 12 working in the frequency band 1 and the first band pass filter 12 is used to output the electromagnetic wave signal The output end feeder head port3, a second bandpass filter 13 working in the frequency band 2 and the second bandpass filter 13 are used to output the output end feeder port4 of the electromagnetic wave signal, a 50 ohm transmission line 14, the medium The other side of the substrate is a ground plane.

The first end of the transmission line 14 is connected to the input feeder head port1, and its second end is connected to the low-pass filter 11; the first band-pass filter 13 and the second band-pass filter 12 are respectively located on the transmission line 14 upper and lower sides.

The transmission line 14 is provided with three positioning points p1, p2, p3, wherein the positioning point p3 is located at the second end of the transmission line 14 as a reference point, and the distance from the positioning point p1 to the positioning point p3 corresponds to four quarters of the center frequency of the first bandpass filter 12 One-quarter wavelength, the distance from the anchor point p2 to the anchor point p3 corresponds to a quarter wavelength of the center frequency of the second band-pass filter 13; the anchor point p1 is used to limit the first band-pass filter 12 to the anchor point The horizontal distance of the point p3, the positioning point p2 is used to define the horizontal distance from the second bandpass filter 13 to the positioning point p3. According to the quarter-wavelength impedance inversion, when the band-pass filter 12 and the band-pass filter 13 are working, p1 and p2 are respectively equivalent to an open circuit state, and the low-pass filter 11 basically has no influence on it. The biggest advantage of this design is that it can Each low-pass band-pass filter can be independently designed without being affected by each other, thereby shortening the design cycle and improving design efficiency.

The structure of the low-pass filter 11 is as shown in Figure 4, including an input feeder 110 for feeding in an electromagnetic wave signal, an output feeder head port2 and an output feeder 1110 for feeding out an electromagnetic wave signal, wherein the input feeder 110 and the output feeder 1110 Both have a matching impedance of 50 ohms. The input feeder 110 is a part of the transmission line 14 , and the first end of the input feeder 110 corresponds to the second end of the transmission line 14 . The end that defines input feeder 110 close to low-pass filter 11 is the first end, that end away from low-pass filter 12 is the second end, and the end that transmission line 14 is close to low-pass filter 11 is the second end, and transmission line 14 The end far away from the low-pass filter 11 is the first end.

The low-pass filter 11 also includes six resonators. The first resonator of the low-pass filter 11 includes a transmission line 1111 and a transmission line 1121, which are vertically connected to form a stub-loaded resonator. The second resonator of the low-pass filter 11 includes a transmission line 1112 and a transmission line 1122, the two are vertically connected to form a stub-loaded resonator, and the first end of the transmission line 1111 and the first end of the transmission line 1112 are respectively connected to the input feeder 110 after being linearly connected. The first ends are connected vertically.

The third resonator of the low-pass filter 11 includes a transmission line 1141 and a transmission line 1151, the two are vertically connected to form a step impedance resonator; the fourth resonator of the low-pass filter 11 includes a transmission line 1142 and a transmission line 1152, and the two are vertically connected to form a Step impedance resonators.

The fifth resonator of the low-pass filter 11 includes a transmission line 1171; the sixth resonator of the low-pass filter 11 includes a transmission line 1172, and the first end of the transmission line 1171 and the first end of the transmission line 1172 are respectively connected to the output feeder 1110 after a straight line. The first ends are connected vertically. The fifth and sixth resonators of the low-pass filter 11 are uniform impedance resonators.

The low-pass filter 11 also includes a high-impedance transmission line 113 and a high-impedance transmission line 116, which are used to connect the six resonators of the low-pass filter 11 to each other. The high-impedance transmission line 113 and the high-impedance transmission line 116 are connected in a straight line. The first, third, and fifth resonators and the second, fourth, and sixth resonators have a vertically symmetrical structure with the high-impedance transmission line 113 and the high-impedance transmission line 116 as center lines. In order to further improve the impedance of the connection line and optimize the performance of low-pass filtering, two first rectangular slits 118 and second rectangular slits 119 of the same size are etched on the corresponding dielectric substrate directly below the high-impedance transmission line 113 and the high-impedance transmission line 116 .

Both the transmission line 111 and the transmission line 115 are folded and bent in order to reduce the size of the low-pass filter 11 . It should be especially noted that, in order to generate two transmission zeros whose frequencies are respectively the center frequencies of the band-pass filter 12 and the band-pass filter 13, the length of the transmission line from the second end of the transmission line 1111 and the second end of the transmission line 1112 to the first end of the input feeder 110 corresponds to For the quarter wavelength corresponding to the center frequency of the first bandpass filter 12, the length of the transmission line from the second end of the transmission line 1121 and the second end of the transmission line 1122 to the first end of the input feeder line 110 corresponds to the center of the second bandpass filter 13 The quarter-wavelength corresponding to the frequency is affected by the slot 118, the transmission line 1151, and the transmission line 1152 in actual design, and there will be deviations, but the effect can be achieved through simulation fine-tuning optimization. Among them, the end of the transmission line 1111 and the transmission line 1112 far away from the input feeder is called the second end, and the end close to it is called the first end. Similarly, the end of the transmission line 1121 and the transmission line 1122 far away from the input feeder is called the second end, and the end near the for the first end.

The structure of the first bandpass filter 12 is as shown in Figure 5, including the input feeder 120 for feeding in the electromagnetic wave signal, the output feeder head port3 and the output feeder 127 for feeding out the electromagnetic wave signal, wherein the input feeder 120 and the output The feeder lines 127 are all matched impedances of 50 ohms.

The first bandpass filter 12 also includes four resonators, the four resonators are respectively the first resonator 121, the second resonator 122, the third resonator 124 and the fourth resonator 126, wherein the first resonator 121 and the resonator length of the fourth resonator 126 are a quarter wavelength corresponding to the center frequency of the first bandpass filter 12, wherein the resonant frequency of the second resonator 122 and the third resonator 124 is the first bandpass filter 124. The center frequency of filter 12.

In addition, one end of the first resonator 121 and the fourth resonator 126 of the first bandpass filter 12 is an open circuit, and the other end is a short circuit, and the short circuit end is provided with a ground via hole to achieve a short circuit effect. The transmission lines of the first resonator 121 and the fourth resonator 126 of the quarter-wavelength first bandpass filter 12 are bent and folded for the purpose of reducing the size.

The second resonator 122 and the third resonator 124 of the first bandpass filter 12 are U-shaped step impedance resonators, and both ends of the U-type step impedance second resonator 122 and the third resonator 124 are open circuits , and the centers of the two are respectively connected with a loaded transmission line stub 123 and a loaded transmission line stub 125 of different lengths, the purpose is to adjust the transmission zero point of the band-pass filter 12 so that it falls in the passband of the band-pass filter 13 to achieve Better isolation effect. The output feeder 127 is also bent, in order to arrange its output port port3 at the edge of the dielectric board for practical use.

Both the input feed and the output feed of the first bandpass filter 12 are performed in a coupled feed manner. The input feeder 120 is coupled to the intermediate transmission line 1212 of the first resonator 121 in the first bandpass filter 12, and the spacing and length of the input feeder 120 and the first resonator 121 coupling can be used to optimize the first bandpass filter 12 in-band characteristics.

The input feeder 120 corresponds to the section from the first end of the transmission line 14 to the anchor point p1; the first resonator 121 of the first bandpass filter 12 includes a left transmission line 1211, a middle transmission line 1212 and a right transmission line 1213, wherein the middle The transmission line 1212 is adjacent to and parallel to the input feeder line 120 , the two ends of the middle transmission line 1212 are vertically connected to the left transmission line 1211 and the right transmission line 1213 , and the right transmission line 1312 is on a straight line with the positioning point p1.

The structure of the second bandpass filter 13 is as shown in Figure 6, including the input feeder 130 for feeding in the electromagnetic wave signal, the output feeder head port4 and the output feeder 135 for feeding out the electromagnetic wave signal, wherein the input feeder 130 and the output The feeder lines 135 are all matched impedances of 50 ohms.

The second bandpass filter also includes four resonators, and the resonator length of each of the above resonators is 1/2 wavelength corresponding to the center frequency of the second bandpass filter 13, wherein the second bandpass filter 13 Both ends of the first resonator 131 and the fourth resonator 134 are open circuits;

Wherein the second resonator 132 and the third resonator 133 of the second bandpass filter 13 are U-shaped resonators, and the openings are opposite, and the two ends of the U-shaped second resonator 132 and the third resonator 133 are both is open.

Both the input feed and the output feed of the second bandpass filter 13 are performed in a coupled feed manner. The input feeder 130 is coupled to the intermediate transmission line 1312 of the first resonator 131 in the second band-pass filter 13, and the distance and length of the input feeder 130 coupled to the first resonator 131 can be used to optimize the second band-pass filter 13 in-band characteristics.

The output feeder 135 is also bent, in order to arrange its output port port4 at the edge of the dielectric board for practical use. The four resonators of the second bandpass filter are bent, one of the purposes of which is to reduce the size.

The input feeder 130 corresponds to the section from the first end of the transmission line 14 to the anchor point p2; the first resonator 131 of the second bandpass filter 13 includes a middle transmission line 1311 and a right side transmission line 1312, wherein the middle transmission line 1311 and the right side transmission line 1312 The input feeder lines 130 are adjacent and parallel, one end of the middle transmission line 1311 is vertically connected to the right transmission line 1312 , and the right transmission line 1312 is on a straight line with the positioning point p2.

The above first bandpass filter 12, second bandpass filter 13 and lowpass filter 11 input feed and output feed adopt tap feed or coupling feed, and their bandwidth is determined by the spacing between the resonators Decide. The above-mentioned transmission line adopts a microstrip line, and is in the form of a straight line or a broken line.

The planar low-pass-band-pass triplexer is integrally fabricated on a double-sided copper-clad dielectric substrate, and can be easily fabricated using techniques such as mechanical engraving, laser engraving, and circuit board corrosion. The core content of the present invention is to standardize the transmission zero point of the low-pass filter and the placement distance of the three filters so that the three filters can be independently designed without mutual influence on their performance.

The planar low-pass band-pass triplexer of this embodiment is fabricated on a polytetrafluoroethylene double-sided copper-clad microstrip board with a dielectric constant of 2.55 and a thickness of 0.8 mm in the form of a printed circuit board. The detailed structure is shown in Figure 1, As shown in 2, 3, and 4, the overall size is 75.5mm×45.2mm, and the simulation results are shown in Figures 5 and 6. The planar low-pass band-pass triplexer has superior performance and meets the requirements of practical use.

Fig. 5, 6 has shown the simulation result of the straight-through effect and isolation effect of planar low-pass band-pass triplexer, and horizontal axis represents the signal frequency of planar low-pass band-pass triplexer in the present invention, and vertical axis represents signal amplitude, wherein S ₁₁ represents the reflection coefficient viewed from port 1, and S _ij (i≠j) represents the transmission coefficient from port j to port i. When a signal is input to a certain port, part of the input power of the signal is reflected back to the signal source, and the reflected power becomes the reflected power. S ₁₁ reflects the relationship between the input power of the signal and the reflected power of the signal, and its corresponding mathematical function is as follows: reflected power/incident power=20*log|S ₁₁ |, and the corresponding mathematical function of S _ij (i≠j) The function is: output power/input power (dB)=20*log|S _ij |.

The -1dB cut-off frequency of the low-pass filter in the planar low-pass band-pass triplexer of the present invention is 1GHz, the stop-band suppression exceeds 24dB, and the highest frequency of the stop-band exceeds 7GHz. The center frequency of the bandpass filter 12 working in the frequency band 1 is 2.4GHz, the insertion loss is less than 2dB, the absolute value of the return loss is greater than 19dB, and the 3dB bandwidth is 240MHz. The center frequency of the bandpass filter 13 working in the frequency band 2 is 5.8GHz, the insertion loss is less than 2.3dB, the absolute value of the return loss is greater than 15dB, and the 3dB bandwidth is 400MHz. In the frequency range of 0-7GH, the absolute value of the isolation degree S ₃₂ of the planar low-pass-band-pass triplexer is greater than 48dB, the absolute value of the isolation degree S ₄₂ is greater than 50dB, and the absolute value of the isolation degree S ₄₃ is greater than 39dB. The planar low-pass band-pass triplexer has superior performance and meets the requirements of practical use.

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations, Simplifications should be equivalent replacement methods, and all are included in the protection scope of the present invention.

Claims (10)

1. plane lower passband leads to a triplexer, is produced on medium substrate in the manner of a printed circuit board, it is characterized in that:

The same face of described medium substrate is manufactured with respectively the input feeder line head port1 for inputting electromagnetic wave signal, low pass filter (11) and its for export electromagnetic wave signal output feeder line head port2, be operated in first band pass filter (12) of frequency range 1 and its for export electromagnetic wave signal output feeder line head port3, be operated in frequency range 2 the second band pass filter (13) and it is for exporting output feeder line head port4, the transmission line (14) of electromagnetic wave signal, the another side of this medium substrate is ground plate;

The first end of described transmission line (14) is connected with described input feeder line head port1, and its second end is connected with described low pass filter (11); Described first band pass filter (12) and the second band pass filter (13) lay respectively at the both sides of described transmission line (14);

Described transmission line (14) is provided with anchor point p1, p2, p3, wherein said anchor point p3 is positioned at the second end of transmission line (14), and described anchor point p1 distinguishes the quarter-wave of corresponding described first band pass filter (12), the second band pass filter (13) centre frequency to described anchor point p3 distance, described anchor point p2 to described anchor point p3 distance;

Described anchor point p1 is for limiting the horizontal range of described first band pass filter (12) to described anchor point p3, and described anchor point p2 is for limiting the horizontal range of described second band pass filter (13) to described anchor point p3.

2. a kind of plane lower passband according to claim 1 leads to triplexer, it is characterized in that: described low pass filter (11) comprises six resonators, incoming feeder (110) and output feeder (1110), the part that described incoming feeder (110) is described transmission line (14), and the first end of described incoming feeder (110) corresponds to the second end of described transmission line (14);

First resonator of described low pass filter (11) comprises transmission line (1111) and transmission line (1121), and the two vertically connects and composes minor matters and loads resonator; Second resonator of described low pass filter (11) comprises transmission line (1112) and transmission line (1122), the two vertically connects and composes minor matters and loads resonator, and the first end of transmission line (1111) is connected with the first end of incoming feeder (110) is vertical after being connected with the first end straight line of transmission line (1112) respectively;

3rd resonator of described low pass filter (11) comprises transmission line (1141) and transmission line (1151), and the two vertically connects and composes step impedance resonator; 4th resonator of described low pass filter (11) comprises transmission line (1142) and transmission line (1152), and the two vertically connects and composes step impedance resonator;

5th resonator of described low pass filter (11) comprises transmission line (1171); The sixth resonator of described low pass filter (11) comprises transmission line (1172), and the first end of transmission line (1171) is connected with the first end of output feeder (1110) is vertical after being connected with the first end straight line of transmission line (1172) respectively;

Described low pass filter (11) also comprises high-impedance transmission line (113) and high-impedance transmission line (116), for six resonators of described low pass filter (11) are interconnected, described high-impedance transmission line (113) is connected with high-impedance transmission line (116) straight line, the first, the 3rd, the 5th resonator of described low pass filter (11) and second, the 4th, sixth resonator line symmetrically structure centered by described high-impedance transmission line (113) and high-impedance transmission line (116).

3. a kind of plane lower passband according to claim 2 leads to triplexer, it is characterized in that: the second end of described transmission line (1111) and transmission line (1112) corresponds to quarter-wave corresponding to described first band pass filter (12) centre frequency to the length of transmission line of the first end of incoming feeder (110), second end of described transmission line (1121) and transmission line (1122) corresponds to quarter-wave corresponding to described second band pass filter (13) centre frequency to the length of transmission line of the first end of incoming feeder (110).

4. a kind of plane lower passband according to claim 2 leads to triplexer, it is characterized in that: the first rectangular aperture (118) and the second rectangular aperture (119) that medium substrate corresponding immediately below described high-impedance transmission line (113) and high-impedance transmission line (116) etch two formed objects.

5. a kind of plane lower passband according to claim 1 leads to triplexer, it is characterized in that: described first band pass filter (12) comprises incoming feeder (120), output feeder (127) and four resonators, first resonator (121) of wherein said first band pass filter (12) and one end of the 4th resonator (126) are open circuit, the other end is short circuit, short-circuit end is provided with grounding through hole, and the resonator length of described first resonator (121) and the 4th resonator (126) is quarter-wave corresponding to described first band pass filter (12) centre frequency,

Second resonator (122) and the 3rd resonator (124) of wherein said first band pass filter (12) are U-shaped step impedance resonator, the two ends of described U-shaped Stepped Impedance second resonator (122) and the 3rd resonator (124) are all open circuits, the center of the two is connected to loaded transmission line minor matters (123) and the loaded transmission line minor matters (125) of different length, and the resonance frequency of described second resonator (122) and the 3rd resonator (124) is the centre frequency of described first band pass filter (12).

6. a kind of plane lower passband according to claim 5 leads to triplexer, it is characterized in that: the first end of the corresponding described transmission line of described incoming feeder (120) (14) is to that section of described anchor point p1;

First resonator (121) of described first band pass filter (12) comprises left side transmission line (1211), intermediate conveyor line (1212) and right side transmission line (1213), wherein said intermediate conveyor line (1212) is adjacent and parallel with described incoming feeder (120), the two ends of described intermediate conveyor line (1212) are vertical with right side transmission line (1213) with described left side transmission line (1211) to be respectively connected, and described right side transmission line (1213) and described anchor point p1 are positioned on straight line.

7. a kind of plane lower passband according to claim 1 leads to triplexer, it is characterized in that: described second band pass filter (13) comprises incoming feeder (130), output feeder (135) and four resonators, the resonator length of each resonator is 1/2nd wavelength corresponding to described second band pass filter (13) centre frequency above, and first resonator (131) of wherein said second band pass filter (13) and the two ends of the 4th resonator (134) are all open circuits;

Second resonator (132) and the 3rd resonator (133) of wherein said second band pass filter (13) are U-shaped resonator, and the two ends of described U-shaped second resonator (132) and the 3rd resonator (133) are all open circuits.

8. a kind of plane lower passband according to claim 7 leads to triplexer, it is characterized in that: the first end of the corresponding described transmission line of described incoming feeder (130) (14) is to that section of described anchor point p2;

First resonator (131) of described second band pass filter (13) comprises intermediate conveyor line (1311) and right side transmission line (1312), wherein said intermediate conveyor line (1311) is adjacent and parallel with described incoming feeder (130), one end of described intermediate conveyor line (1311) is connected with described right side transmission line (1312) is vertical, and described right side transmission line (1312) and described anchor point p2 are positioned on straight line.

9. a kind of plane lower passband according to claim 1 leads to triplexer, it is characterized in that: the input feed of described first band pass filter (12), described second band pass filter (13) and described low pass filter (11) or export feed and adopt tap feed or couple feed.

10. lead to triplexer according to the arbitrary described a kind of plane lower passband of claim 1 to 9, it is characterized in that: described transmission line adopts microstrip line, and is the form of straight line or broken line.