CN217468748U

CN217468748U - Cavity combiner

Info

Publication number: CN217468748U
Application number: CN202220231477.0U
Authority: CN
Inventors: 陈国梁; 张刚; 吴委; 杜军
Original assignee: Hengerwei Technology Suzhou Co ltd
Current assignee: Hengerwei Technology Suzhou Co ltd
Priority date: 2022-01-27
Filing date: 2022-01-27
Publication date: 2022-09-20
Anticipated expiration: 2032-01-27

Abstract

The utility model discloses a cavity combiner, which comprises a cavity, wherein an upper cover plate is arranged at the top of the cavity, a lower cover plate is arranged at the bottom of the cavity, a debugging cover plate is arranged between the upper cover plate and the cavity, the cavity is internally divided into a high-frequency channel and a low-frequency channel, an ultra-wideband interdigital filter is arranged in the high-frequency channel, and an ultra-wideband band elimination filter is arranged in the low-frequency channel; a low-frequency port connector and a high-frequency port connector are arranged at one end of the outer side of the cavity, a public port connector is arranged at the other end of the outer side of the cavity, the low-frequency port connector is connected with the ultra-wideband band elimination filter through a transmission line, and the high-frequency port connector is connected with the ultra-wideband interdigital filter through a high-frequency port tap piece; the ultra-wideband interdigital filter is connected with the combining end transmission line through the common end tap piece and the ultra-wideband band-stop filter piece and then connected with the common port connector. The utility model discloses an ultra wide band, small, low-loss, high isolation and the high intermodulation of combiner.

Description

Cavity combiner

Technical Field

The utility model belongs to the technical field of communication, in particular to cavity combiner.

Background

With the rapid popularization of the 5G technology, the spectrum resources for mobile communication are more and more abundant, and the frequency is gradually increased with the increase of the frequency band. In order to achieve the purposes of better compatibility of transmission of different frequency signals such as broadcasting, television, 2G, 3G, 4G, 5G and the like and saving the cost of a network optimization and indoor distribution system, the requirements of ultra wide band, miniaturization, low cost and high performance are provided for a radio frequency device used for the network optimization and indoor distribution system.

Ultra-wideband has been an industry challenge for radio frequency devices. The coupling mode between the resonant units and the coupling mode of the ports of the ultra-wideband filter are the most important difficulties. This difficulty is amplified for an ultra-wideband combiner comprising ultra-wideband filters, because not only the difficulty of a single ultra-wideband filter is to be solved, but also the mutual influence generated when two or more ultra-wideband filters are combined is to be solved. Therefore, the selection of the single ultra-wideband filter and the processing of the common port of the ultra-wideband combiner become the key to solve the problem and design and produce the ultra-wideband combiner.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a cavity combiner to realize ultra wide band, little volume, low-loss, high isolation and the high intermodulation of combiner.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a cavity combiner comprises a cavity, wherein an upper cover plate is arranged at the top of the cavity, a lower cover plate is arranged at the bottom of the cavity, a debugging cover plate is arranged between the upper cover plate and the cavity, the cavity is internally divided into a high-frequency channel and a low-frequency channel, an ultra-wideband interdigital filter is arranged in the high-frequency channel, and an ultra-wideband band elimination filter is arranged in the low-frequency channel; a low-frequency port connector and a high-frequency port connector are arranged at one end of the outer side of the cavity, a public port connector is arranged at the other end of the outer side of the cavity, the low-frequency port connector is connected with the ultra-wideband band elimination filter through a transmission line, and the high-frequency port connector is connected with the ultra-wideband interdigital filter through a high-frequency port tap piece; the ultra-wideband interdigital filter is connected with the combining end transmission line through the common end tap piece and the ultra-wideband band-stop filter piece and then connected with the common port connector.

The high-frequency port tap piece and the public end tap piece are both supported and installed in the cavity through the tap pieces, and the tap piece supports are made of insulating materials.

The inner surface of the upper cover plate is provided with an upper waterproof ring, a debugging cover plate is arranged below the upper waterproof ring, a lower waterproof ring is arranged on the inner surface of the lower cover plate, and a lower shielding cover plate is arranged above the lower waterproof ring.

Threaded holes of various specifications are reserved on the debugging cover plate.

The transmission line is a 50 omega transmission line.

The combiner end transmission line is a T-shaped connecting rod, and the T-shaped connecting rod is provided with three connecting ends which are respectively connected with a public end connector, a band elimination filter sheet of a band elimination filter in a low-frequency channel and a public end tap sheet of an ultra-wideband interdigital filter in a high-frequency channel; the combiner end transmission line is in the form of a stepped impedance.

The combined end transmission line is in a step impedance form of 50-35-50 omega, namely, the connection end of the combined end transmission line connected with the band elimination filter sheet of the band elimination filter in the low-frequency channel is a transmission line with 35 omega impedance, and the connection ends of the combined end transmission line connected with the public end connector and the public end tap sheet of the ultra-wideband interdigital filter in the high-frequency channel are transmission lines with 50 omega impedance.

The combining end transmission line and the combining port connector are integrated.

And the combined end transmission line is respectively connected with a band elimination filter sheet of the band elimination filter in the low-frequency channel and a common end tap sheet of the ultra-wideband interdigital filter in the high-frequency channel in a welding manner.

Has the beneficial effects that: compared with the prior art, the utility model has the advantages of it is following:

1. ultra wide band: the low-frequency channel passband frequency of the utility model covers from DC to 960MHz, and the ultra-wideband passband bandwidth close to 1000MHz is realized; the low-frequency channel stop band frequency of the utility model covers 1695MHz to 3900MHz, and the ultra-wide band stop band bandwidth of 2205MHz is realized; the utility model discloses a high frequency channel has covered from 1695MHz to 3900MHz, has realized 2205 MHz's ultra wide band passband bandwidth, and band pass filter's relative bandwidth has reached nearly 79%;

2. small volume: the utility model discloses under same frequency and index requirement, realized than the volume that like product is littleer on the market, the utility model discloses an overall dimension does: 152X 102X 35 (length X width X height, unit: mm, without mounting bracket dimensions), is reduced by about 1/3 compared to a similar product;

3. low loss, high isolation: the insertion loss of the duplexer is less than-0.15 dB, the return loss is less than-20 dB, and the mutual isolation between the two pass bands is less than-51.5 dB;

4. high intermodulation: the utility model has simple structure, good effect of three-order intermodulation test, high intermodulation passing rate and three-order intermodulation of less than-168 dBc (2 multiplied by 20W);

5. high mass productivity, low cost: the utility model discloses simple structure, easily mass production, the through rate is high, and is with low costs.

Drawings

Fig. 1 is an assembly view of the cavity combiner of the present invention;

fig. 2 is an internal structure diagram of the cavity combiner of the present invention.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings.

As shown in fig. 1 and 2, the cavity combiner of the present invention comprises a cavity 8, wherein an upper cover plate 1 is disposed at the top of the cavity 8, a lower cover plate 11 is disposed at the bottom of the cavity, a debugging cover plate 3 is disposed on the inner surface of the upper cover plate 1, the cavity 8 is divided into a high frequency channel and a low frequency channel, an ultra wide band interdigital filter is disposed in the high frequency channel, and an ultra wide band stop filter is disposed in the low frequency channel; a low-frequency port connector 15 and a high-frequency port connector 16 are arranged at one end of the outer side of the cavity 8, a common port connector 14 is arranged at the other end of the outer side of the cavity, the low-frequency port connector 15 is connected with the ultra-wideband band-stop filter through a transmission line 13, and the high-frequency port connector 16 is connected with the interdigital filter through a high-frequency port tap piece 12; the ultra-wideband interdigital filter is connected with the combining end transmission line through the common end tap piece and the ultra-wideband band-stop filter and then connected with the common port connector.

The interdigital filter comprises N resonators 17 arranged in a high-frequency channel, wherein the N resonators 17 are arranged in series in a staggered mode and are coupled according to the Chebyshev distribution rule to form an N-order interdigital filter. The resonator 17 has a length of λ/4 of the center frequency of the high-frequency channel, where λ is the wavelength of the resonance frequency, and one end of the resonator 17 is grounded and the other end is open. The interdigital filter has the characteristics of compact structure, high reliability, low tolerance requirement, easiness in manufacturing and high Q value. Such a filter: the volume is small, the weight is light, the loss is extremely small, the cut-off frequency is unusually steep, the parasitic passband is far away from the central frequency, and the process is simple and easy to produce. The interdigital filter has a structure and a design method suitable for various bandwidths, can realize a band-pass filter with the relative bandwidth of 0.5-100%, is particularly suitable for being used as an ultra-wideband band-pass filter in an open-ended mode. The utility model discloses an interdigital filter has adopted the form that the terminal was opened a way, has realized the ultra wide band filter that relative bandwidth is about 79%. The interdigital filter composed of the resonators 17 can shorten the length of the resonators from lambda/4 of the channel center frequency of a theoretical value to lambda/8 or even smaller due to the existence of the capacitance loading effect, and the volume of a product can be greatly reduced.

The ultra-wideband band-stop filter comprises a band-stop filter sheet 4 arranged in a low-frequency channel, wherein the band-stop filter sheet 4 is arranged in the low-frequency channel of a cavity 8 through a plurality of band-stop filter sheet supports 6 to form the ultra-wideband band-stop filter. The ultra-wideband band-stop filter composed of the band-stop filter sheet 4, the band-stop filter sheet support 6 and the cavity 8 has the characteristics of wide pass band width, wide stop band width and long stop band pass band interval, and is very suitable for a low-frequency channel in an ultra-wideband combiner, especially under the condition that the bandwidth required by the low-frequency channel is very wide. The resonant frequency of the ultra-wideband band-stop filter is out of band, and the position of the resonant frequency can be effectively controlled by adjusting the size of the capacitor branch 19 of the band-stop filter sheet to form a transmission zero point, so that the stop band is well restrained, and under the condition of the same number of branches, the band-stop filter can save more volumes and reduce the material cost and the space cost. The resonance frequency of the ultra-wideband band-stop filter is out of band, so that the ultra-wideband band-stop filter has attenuation on input signals and intermodulation signals, and compared with a band-pass filter, the ultra-wideband band-stop filter has the advantages of incomparable power capacity and intermodulation. The resonance frequency of the ultra-wideband band-stop filter is in the high-frequency part of the combiner, and the theoretical formula shows that lambda is c/f (lambda is the wavelength of the resonance frequency, f is the resonance frequency, and c is the light speed 3 x 10 x 8m/s), the higher the resonance frequency is, the smaller the wavelength of the resonance frequency is, and the smaller the physical size is, so the band-stop filter is adopted as the low-pass channel of the combiner, and the product volume can be effectively reduced.

The high-frequency port tap piece 12 and the public end tap piece 5 are both arranged in the cavity 8 through the tap piece support 7, and the tap piece support 7 is made of insulating materials. Because the tap piece support 7 is made of insulating materials, the cavity 8 of the metal structure and the common-end tap piece 5 of the metal structure can be completely isolated from the high-frequency port tap piece 12, and third-order intermodulation generated by nonlinearity of metal contact is avoided.

The inner surface of the upper cover plate 1 is provided with an upper waterproof ring 2, a debugging cover plate 3 is arranged below the upper waterproof ring 2, a lower waterproof ring 10 is arranged on the inner surface of the lower cover plate 11, and a lower shielding cover plate 9 is arranged above the lower waterproof ring 10. Because waterproof rings are designed between the upper waterproof cover plate, the lower waterproof cover plate and the cavity, the waterproof ring can be used for outdoor use.

Threaded holes with various specifications are reserved on the debugging cover plate 3.

The transmission line 13 is a 50 Ω transmission line.

The combining end transmission line 18 is a T-shaped connection rod having three connection ends respectively connected to the common end connector, the band-stop filter piece 4 of the band-stop filter in the low-frequency channel, and the common end tap piece 5 of the ultra-wideband interdigital filter in the high-frequency channel. The combined end transmission line 18 is in a step impedance form of 50-35-50 omega, namely, the connection end of the combined end transmission line connected with the band elimination filter sheet 4 of the band elimination filter in the low-frequency channel is a transmission line with 35 omega impedance, and the connection ends of the combined end transmission line connected with the public end connector and the public end tap sheet 5 of the ultra-wideband interdigital filter in the high-frequency channel are transmission lines with 50 omega impedance. The combining end transmission line 18 and the combining port connector are integrated. The combined path end transmission line 18 is respectively connected with the band elimination filter sheet 4 of the band elimination filter in the low frequency channel and the common end tap sheet 5 of the ultra wide band interdigital filter in the high frequency channel in a welding way. The low-frequency channel band-stop filter and the high-frequency channel interdigital filter are connected by a T-shaped structure, so that the stability of a product can be improved, and the production is easy. Different from the traditional mode that the common end adopts 50 omega connection, simulation software simulation can be used for obtaining that when a transmission line with impedance of about 35 omega is adopted to connect the low-frequency channel band elimination filter, the influence of the low-frequency channel on the high-frequency channel can be effectively counteracted during combination. When the combined end transmission line is connected with the common end tap chip 5, the transmission line with 50 omega impedance is still adopted for connection, and the influence on a high-frequency channel is minimum at the moment. The combiner-side transmission line thus takes the form of a 50 Ω -35 Ω -50 Ω stepped impedance.

The present invention will be further described with reference to the following specific embodiments.

The present invention can be better understood in light of the following examples. However, it is easily understood by those skilled in the art that the specific material ratios, process conditions and results described in the examples are only for illustrating the present invention, and should not limit the present invention described in detail in the claims.

Examples

The working frequency of the combiner of the embodiment is DC-960MHz/1695MHz-3900 MHz. As shown in fig. 1 and 2: in a DC-960MHz frequency band, a 9-order air stripline band elimination filter is adopted, and the 9-order air stripline band elimination filter consists of 4 capacitance branches 19 and 5 inductance branches 20; 1695-3900MHz band, a 9-order interdigital band-pass filter is adopted, which is composed of 9 resonators 17 arranged in a staggered way; the combining part adopts a T-shaped structure to connect a high channel and a low channel; a high-frequency port tap piece 12 of the high-frequency channel interdigital filter is separated from the position right below a common end tap piece head 5 by a tap piece support 7 made of an insulating material ultem 1000, so that the tap piece and a head cavity and a tail cavity are coupled in a capacitive coupling mode, direct-current signals are effectively blocked from passing, passive intermodulation caused by nonlinearity of metal contact is avoided, and the reliability and the passing rate of a product are improved; the band elimination filter of the low-frequency channel is led out from the interior of the cavity by the 50 omega transmission line 13 and is connected with the 50 omega connector of the low-frequency port, so that the distance between the high-frequency connector and the low-frequency connector is ensured under the condition that the performance of the low-frequency channel is not deteriorated, and the band elimination filter is easy to install and test; the upper surface and the lower surface of the cavity are both provided with waterproof rings and waterproof cover plates, and three waterproof joints are added, so that the product meets the IP68 requirement and can be used indoors or outdoors.

In the band-stop filter of the low-frequency channel in the embodiment, the passband frequency is DC-960MHz, the stopband frequency of-50 dB isolation can be 1695-3900MHz, and under the condition of meeting the requirement of passband performance, 4 resonance frequencies generated by 4 capacitor branches 19 are distributed in the range of the stopband frequency 1695-3900MHz, so that the ultra-wideband stopband is realized under the condition of ensuring the realization of the ultra-wideband passband.

In the interdigital band-pass filter of the high-frequency channel in the embodiment, the relative bandwidth reaches nearly 79%, and the interdigital band-pass filter has a good rectangular coefficient, so that better inter-channel isolation can be obtained. The width of the resonator 17 of the interdigital filter is 5mm, so that the reliability and stability of the resonator can be effectively improved. Wherein the thickness of the syntonizer 17 of interdigital filter is 6mm, when increasing reliability and stability, makes the coupling area increase between the syntonizer, and the coupling coefficient between two liang syntonizers increases to physical interval between the syntonizer has been increased, the utility model discloses in, the minimum distance between the syntonizer is 3mm, very big increase the producibility of product, also reduced the tolerance requirement to interval between the syntonizer.

In the embodiment, the public port combining part adopts a T-shaped structure to connect the high channel and the low channel, the T-shaped connecting rod adopts a 50-35-50 omega step impedance form, and the transmission line is welded with the band elimination filter sheet 4 at the middle 35 omega position, so that the influence of the low frequency channel on the high frequency channel during combining is effectively eliminated, and the energy required by the band elimination filter is distributed on the premise of ensuring the energy required by the high frequency part tap. And the tail end of the transmission line adopts 50-ohm impedance, so that the influence of a low-frequency channel on a high-frequency channel during combination is reduced to the minimum.

The utility model discloses in, leave the screw hole of multiple specification on debugging apron 3, the convenience is in process of production, and it is bad owing to the performance that the machining error of assembly and part caused to add silver-plated brass screw debugging, has increased the producibility of product.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A cavity combiner is characterized in that: the ultra-wideband interdigital filter comprises a cavity (8), wherein an upper cover plate (1) is arranged at the top of the cavity (8), a lower cover plate (11) is arranged at the bottom of the cavity, a debugging cover plate (3) is arranged between the upper cover plate (1) and the cavity (8), the cavity (8) is internally divided into a high-frequency channel and a low-frequency channel, an ultra-wideband interdigital filter is arranged in the high-frequency channel, and an ultra-wideband band-stop filter is arranged in the low-frequency channel; a low-frequency port connector (15) and a high-frequency port connector (16) are arranged at one end of the outer side of the cavity (8), a common port connector (14) is arranged at the other end of the outer side of the cavity, the low-frequency port connector (15) is connected with the ultra-wideband band rejection filter through a transmission line (13), and the high-frequency port connector (16) is connected with the ultra-wideband interdigital filter through a high-frequency port tap piece (12); the ultra-wideband interdigital filter is connected with a combining end transmission line (18) through a common end tap piece (5) and an ultra-wideband band-stop filter piece (4), and then is connected with a common port connector (14).

2. The cavity combiner of claim 1, wherein: the high-frequency port tap piece (12) and the public end tap piece (5) are both arranged in the cavity (8) through the tap piece support (7), and the tap piece support (7) is made of insulating materials.

3. The cavity combiner of claim 1, wherein: the inner surface of the upper cover plate (1) is provided with an upper waterproof ring (2), a debugging cover plate (3) is arranged below the upper waterproof ring (2), a lower waterproof ring (10) is arranged on the inner surface of the lower cover plate (11), and a lower shielding cover plate (9) is arranged above the lower waterproof ring (10).

4. The cavity combiner of claim 1, wherein: threaded holes of various specifications are reserved on the debugging cover plate (3).

5. The cavity combiner of claim 1, wherein: the transmission line (13) is a 50 omega transmission line.

6. The cavity combiner of claim 1, wherein: the combined circuit end transmission line (18) is a T-shaped connecting rod, and the T-shaped connecting rod is provided with three connecting ends which are respectively connected with a public end connector, a band elimination filter sheet (4) of a band elimination filter in a low-frequency channel and a public end tap sheet (5) of an ultra-wideband interdigital filter in a high-frequency channel; the combiner end transmission line (18) is of stepped impedance form.

7. The cavity combiner of claim 6, wherein: the combined end transmission line (18) is in a step impedance form of 50-35-50 omega, namely, the connection end of the combined end transmission line connected with the band elimination filter sheet (4) of the band elimination filter in the low-frequency channel is a transmission line with 35 omega impedance, and the connection end of the combined end transmission line connected with the public end connector and the public end tap sheet (5) of the ultra-wideband interdigital filter in the high-frequency channel is a transmission line with 50 omega impedance.

8. The cavity combiner of claim 6, wherein: the combining end transmission line (18) and the combining port connector are integrated.

9. The cavity combiner of claim 6, wherein: and the combined end transmission line (18) is respectively connected with a band elimination filter sheet (4) of a band elimination filter in a low-frequency channel and a common end tap sheet (5) of an ultra-wideband interdigital filter in a high-frequency channel in a welding manner.