CN113346205B - Continuous same broadband triplexer of generalized Chebyshev function response channel - Google Patents
Continuous same broadband triplexer of generalized Chebyshev function response channel Download PDFInfo
- Publication number
- CN113346205B CN113346205B CN202110524331.5A CN202110524331A CN113346205B CN 113346205 B CN113346205 B CN 113346205B CN 202110524331 A CN202110524331 A CN 202110524331A CN 113346205 B CN113346205 B CN 113346205B
- Authority
- CN
- China
- Prior art keywords
- pass filter
- band
- low
- substrate
- output end
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
- H01P1/00—Auxiliary devices
- H01P1/20—Frequency-selective devices, e.g. filters
Abstract
The invention discloses a continuous same broadband triplexer of a generalized Chebyshev function response channel, which comprises five layers of substrates which are sequentially laminated and ten metal layers which are respectively arranged on the upper side and the lower side of the five layers of substrates; and the upper side and the lower side of the third layer of substrate are provided with a substrate integrated suspension microstrip line structure consisting of a high-low pass cascade band-pass filter, and the substrate integrated suspension microstrip line structure is grooved along the edge of the circuit. The high-pass filter is designed in a cross coupling mode between non-adjacent narrow-band microstrip branches, and the adjustment and control of the position of the transmission zero frequency are realized; the design of a multi-transmission zero low-pass filter is realized by adopting a parallel open-circuit branch knot mode; the structure form of cascade high and low filters is adopted, so that the flexibility and adjustability of the pass band and the center frequency are convenient to realize, and the method is suitable for the design of a continuous pass band multiplexer and a discontinuous pass band multiplexer; the microwave circuit has the advantages of high out-of-band rejection, small insertion loss, high integration level and the like, and has wide application prospect in microwave circuits.
Description
Technical Field
The invention relates to the technical field of filters and multiplexers, in particular to a broadband triplexer with continuous same response channels of generalized Chebyshev functions.
Background
With the development of multi-frequency systems, multiplexers are widely used in communication systems. The multiplexer is adopted to perform channelized filtering processing on the broadband spectrum so as to improve the utilization rate of frequency resources, and the method is one of key technologies of a multichannel communication system. The high-performance multiplexer can effectively improve the quality of signal processing, for example, a filter in the multiplexer has passband selectivity and can effectively inhibit the interference of useless signals; the low insertion loss in the channel band can effectively increase the sensitivity of the receiver or reduce the requirement of the transmitter on the high gain of the amplifier. The traditional multiplexer structure includes cavity, substrate integrated waveguide, microstrip star, multimode structure, etc. The cavity multiplexer is usually formed by combining three-dimensional microwave resonant cavities, and has the defects of heavy weight, large volume, difficulty in integration and the like. The substrate integrated waveguide triplexer has the characteristic of small insertion loss, but the problems of large volume and low integration level cannot be overcome. The microstrip star-junction multiplexer is the most common planar structure, and although the structure is simple, the number of channels is limited, the insertion loss is inversely proportional to the order (out-of-band rejection), and the interference between the channels of the multiplexer is very serious. The multimode structure has the advantage of convenient design of the microstrip structure, but the out-of-band rejection degree is difficult to improve. Multiplexers can be generally divided into two types, "channel-continuous" and "channel-discontinuous", depending on whether the channels of the multiplexer are continuous or not. On the one hand, good out-of-band rejection of the continuous channel multiplexer is the best way to efficiently utilize the spectrum resources, and on the other hand, since adjacent channels overlap in the channel continuous multiplexer, mutual interference between the channels is more likely to occur, and thus the design difficulty of the channel continuous multiplexer is greater than that of the channel non-continuous multiplexer. Therefore, how to solve the problem of sideband suppression between passbands of the passband continuous multiplexer is a problem currently faced.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a generalized Chebyshev response, continuous channel and same broadband triplexer with a plurality of transmission zeros based on a cascade structure of high-low pass filters.
In order to achieve the purpose of the invention, the invention adopts the technical scheme that:
a broad band triplexer with continuous and same generalized Chebyshev function response channels comprises five layers of substrates which are sequentially stacked and ten metal layers which are respectively arranged on the upper side and the lower side of the five layers of substrates; the middle parts of the second layer substrate and the fourth layer substrate are respectively provided with a first air cavity and a second air cavity, the upper side and the lower side of the third layer substrate are provided with a substrate integrated suspension microstrip line structure formed by high-low pass cascade band-pass filters, and the substrate integrated suspension microstrip line structure is grooved along the edge of a circuit.
Further, the substrate integrated suspension microstrip line structure comprises a first band-pass filter, a second band-pass filter and a third band-pass filter which are sequentially cascaded and adopt double-sided complete overlapping coupling, double-sided partial overlapping coupling and a single-sided circuit structure, wherein the input end of the first band-pass filter is connected with the input end of the triplexer, and the output ends of the first band-pass filter, the second band-pass filter and the third band-pass filter are respectively connected with the first output end, the second output end and the third output end of the triplexer.
Further, the first band pass filter comprises a first low pass filter, a first matching network, and a first high pass filter; the input end of the first low-pass filter is connected with the input end of the triplexer, and the output end of the first low-pass filter is connected with the input end of the first matching network; a first output end of the first matching network is connected with an input end of the second band-pass filter, and a second output end of the first matching network is connected with an input end of the first high-pass filter; and the output end of the first high-pass filter is connected with the first output end of the triplexer.
Further, the second band-pass filter comprises a second low-pass filter, a second matching network, and a second high-pass filter; the input end of the second low-pass filter is connected with the first output end of the first matching network, and the output end of the second low-pass filter is connected with the input end of the second matching network; a first output end of the second matching network is connected with an input end of the third band-pass filter, and a second output end of the second matching network is connected with an input end of the second high-pass filter; and the output end of the second high-pass filter is connected with the second output end of the triplexer.
Further, the third band-pass filter includes a third low-pass filter and a third high-pass filter; the input end of the third low-pass filter is connected with the first output end of the second matching network, and the output end of the third low-pass filter is connected with the input end of the third high-pass filter; and the output end of the third high-pass filter is connected with the third output end of the triplexer.
Furthermore, the first low-pass filter, the second low-pass filter and the third low-pass filter all adopt the same low-pass filter circuit structure, and the low-pass filter circuit structure comprises an input port arranged at the upper side of the third layer of substrate, a 6-order Chebyshev low-pass filter adopting parallel open-circuit branches and an output port; the input port and the output port are both converted into conductor line widths of 50 ohms by adopting step impedance; the 6-order Chebyshev low-pass filter adopts a cascade resonator structure, wherein a first-order resonator and second-order to sixth-order resonators which are linearly arranged are bent at 90 degrees.
Furthermore, the first high-pass filter, the second high-pass filter and the third high-pass filter all adopt the same high-pass filter circuit structure, and the high-pass filter circuit structure comprises an input port arranged on the upper side of the third layer of substrate, an output port arranged on the lower side of the third layer of substrate and 9-order Chebyshev high-pass filters arranged on the upper side and the lower side of the third layer of substrate; the 9-order Chebyshev high-pass filter adopts a suspended microstrip double-sided coupling structure and comprises a first metal conduction band, a first narrow-band open-circuit stub, a second metal conduction band, a second narrow-band open-circuit stub and a third metal conduction band which are arranged on the upper side of a third layer substrate in a T-shaped manner, a fourth metal conduction band, a fourth narrow-band open-circuit stub, a fifth metal conduction band, a fifth narrow-band open-circuit stub and a sixth metal conduction band, wherein the fourth metal conduction band, the fourth narrow-band open-circuit stub, the fifth metal conduction band, the fifth narrow-band open-circuit stub and the sixth metal conduction band are arranged on the lower side of the third layer substrate in a T-shaped manner; the first metal conduction band and the second metal conduction band, the fourth metal conduction band and the fifth metal conduction band are simultaneously arranged on the upper side and the lower side of the third layer of substrate to form an overlapped coupling structure, and cross-coupled lines are connected to the tail ends of the fourth narrow-band open-circuit stub and the fifth narrow-band open-circuit stub of non-adjacent branches.
Furthermore, the ends of the first, second, fourth and fifth narrow-band open-circuited stubs of the third high-pass filter are respectively connected to the open-ended stub structures of the step impedance.
Furthermore, the first layer of substrate is provided with an opening of the input end microstrip line, the second layer of substrate is provided with an opening of the input end microstrip line and the substrate supporting bridge, the fourth layer of substrate is provided with three openings of the output end microstrip line and the substrate supporting bridge, and the fifth layer of substrate is provided with three openings of the output end microstrip line.
Furthermore, input microstrip line taps are arranged at positions, corresponding to the openings of the first layer substrate and the second layer substrate, on the upper side of the third layer substrate, and output microstrip line taps are arranged at positions, corresponding to the openings of the fourth layer substrate and the fifth layer substrate, on the lower side of the third layer substrate.
The invention has the following beneficial effects:
the invention adopts a cross coupling mode between non-adjacent narrow-band microstrip branches to design a high-pass filter, and realizes the regulation and control of the position of the transmission zero frequency; the design of a multi-transmission zero low-pass filter is realized by adopting a parallel open-circuit branch node mode; the structure form of cascade high and low filters is adopted, so that the flexible adjustment of the pass band and the center frequency is convenient to realize, and the method is suitable for the design of a continuous pass band multiplexer and a discontinuous pass band multiplexer; the microwave circuit has the advantages of high out-of-band rejection, small insertion loss, high integration level and the like, and has wide application prospect in microwave circuits.
Drawings
FIG. 1 is a schematic cross-sectional view of the present invention;
FIG. 2 is a schematic diagram of a triplexer architecture of the present invention; wherein, the diagram (a) is a schematic diagram of a high-pass, a low-pass and a matching network, the diagram (b) is a schematic diagram of a triplexer cascade connection composition, and the diagram (c) is a schematic diagram of a composition passage of the triplexer;
FIG. 3 is a schematic cross-sectional diagram of a substrate integrated suspension stripline single-sided circuit of the present invention;
FIG. 4 is a schematic diagram of a dual port resonator structure of the present invention; wherein, the diagram (a) is a physical layout diagram, and the diagram (b) is an equivalent LC circuit diagram;
FIG. 5 is a diagram illustrating a variation curve of the transmission zero frequency position according to the present invention;
FIG. 6 is a schematic diagram of the physical layout of the low pass filter of the present invention;
FIG. 7 is a diagram illustrating simulation curves of a low-pass filter according to the present invention;
FIG. 8 is a schematic diagram of a cross-coupled 7 th order high pass filter LC circuit of the present invention;
FIG. 9 is a schematic diagram of the parity mode excitation of the double-sided partially overlapped circuit of the present invention;
FIG. 10 is a schematic diagram of the HPF planar circuit structure of the present invention;
FIG. 11 is a schematic diagram of the HPF frequency response of the present invention; wherein, the graph (a) is the frequency response curve diagram of the HPF1, the graph (b) is the frequency response curve diagram of the HPF2, and the graph (c) is the frequency response curve diagram of the HPF 3;
FIG. 12 is a schematic circuit diagram of a BPF1 according to the present invention; wherein fig. (a) is a top view and fig. (b) is a bottom view;
FIG. 13 is a schematic diagram of the frequency response curve of the bandpass filter of the present invention; wherein fig. (a) is a schematic diagram of a frequency response curve of the BPF1, fig. (b) is a schematic diagram of a frequency response curve of the BPF2, and fig. 3 is a schematic diagram of a frequency response curve of the BPF 3;
FIG. 14 is a top view of a triplexer of the present invention; wherein, the drawing (a) is a G5 side view, and the drawing (b) is a G6 side view;
FIG. 15 is a schematic view of a triplexer assembly of the present invention;
FIG. 16 is a schematic diagram of the frequency response curve of the triplexer electromagnetic simulation of the present invention;
FIG. 17 is a diagram illustrating the results of the triplexer test of the present invention.
Detailed Description
The following description of the embodiments of the present invention is provided to facilitate the understanding of the present invention by those skilled in the art, but it should be understood that the present invention is not limited to the scope of the embodiments, and it will be apparent to those skilled in the art that various changes may be made without departing from the spirit and scope of the invention as defined and defined in the appended claims, and all matters produced by the invention using the inventive concept are protected.
Referring to fig. 1, an embodiment of the present invention provides a broadband triplexer with a continuous and same wide-band Chebyshev function response channel, including five layers of substrates stacked in sequence and ten layers of metal layers respectively disposed on upper and lower sides of the five layers of substrates; the middle parts of the second layer substrate and the fourth layer substrate are respectively provided with a first air cavity and a second air cavity, the upper side and the lower side of the third layer substrate are provided with a substrate integrated suspension microstrip line structure formed by high-low pass cascade band-pass filters, and the substrate integrated suspension microstrip line structure is grooved along the edge of a circuit.
The invention adopts a substrate integrated suspension microstrip circuit structure formed by five layers of substrates and slotted along a circuit, as shown in figure 1. Consists of five layers of substrates (4 layers of FR-4 sheet materials with the thickness of 1mm and a layer of Rogers5880 sheet materials with the thickness of 0.127 mm) and ten layers of metal conductors (G1-G10), which are positioned at the upper side and the lower side of each layer of substrate. Wherein Rogers RT/duroid5880, dielectric constant ε r1=2.2; the other substrates were low-cost, 1mm thick FR-4 epoxy resin plates with a dielectric constant ∈ r2=4.4. Three circuits, double-sided full overlap coupling (DC), double-sided partial overlap coupling (DPC) and single-sided circuit (SDC), are designed on metal layers G5 and G6. And the grooves are formed along two sides of the circuit, particularly the grooves can be formed on two sides of the circuit with larger current density, so that the loss of the conductor can be reduced, and the characteristic of the air waveguide is realized. The rivet holes are called as RTH, and are used for riveting five layers of substrates together, and two air cavities (air cavities) can be formed on the upper side and the lower side of the Rogers RT/duroid5880 substrate in combination with the plated through holes penetrating through the whole substrate and the conductive layer, so that an electromagnetic field can be enclosed in the cavities, and energy radiation is reduced.
In the substrate integrated suspension microstrip line circuit, the electromagnetic wave transmitted in an air layer can be locked through the shielding effect of the circuit board between the upper layer and the lower layer, and the influence on other systems due to energy radiation can not be generated, so the substrate integrated suspension microstrip line circuit has the characteristics of small volume, self-packaging and high integration level, and overcomes the defects of the traditional waveguide suspension microstrip line; the slot is formed on the edge of the circuit, so that the characteristic of small loss of the suspended integrated waveguide is kept, and the limitation on the thickness of the substrate is broken.
Then, the invention provides a high-pass and low-pass generalized Chebyshev function filter implementation method, and the design of the high-pass and low-pass filters with a plurality of transmission zeros is realized. Designing a plurality of transmission zero low-pass filter coupling structures by adopting stepped impedance, and designing a plurality of substrate integrated suspension microstrip line structure low-pass filters with transmission zeros and cut-off frequencies of 4GHz, 5GHz and 6GHz by adopting a principle of analyzing transmission zeros by using a lumped parameter analysis method and a frequency position control method; meanwhile, a method for realizing cross coupling by adopting a coupling line structure in a high-pass filter so as to introduce a transmission zero point is provided, the frequency position of the transmission zero point of the high-pass filter can be controlled by adjusting the coupling strength of the cross coupling structure, and then a plurality of substrate integrated suspension microstrip line structure high-pass filters with transmission zero points and cut-off frequencies of 3GHz, 4GHz and 5GHz are designed. The low-pass filter, the high-pass filter and the branch matching are adopted for multi-stage integration, an integrated schematic diagram is shown in figure 2, and a schematic diagram of the high-low-pass cascade and component cascade distribution principle of the continuous passband triplexer is shown in figure 2.
Finally, the invention provides an integrated waveguide suspension microstrip technology of a circuit slotting structure to complete the design and processing of a triplexer with three continuous pass bands of 4-5 GHz, 5-6 GHz and 6-7 GHz and a plurality of transmission zeros at the side band. The triplexer has the advantages of controllable bandwidth, continuous channels, high isolation between the channels, low insertion loss, convenience in integration and the like. The triplexer or multiplexer designed by the method can be expanded and applied to the design of a continuous passband/discontinuous channel multiplexer and a same bandwidth/non-same bandwidth multiplexer.
Fig. 2 shows a schematic block diagram of a continuous channel triplexer integrated by three low-pass, three high-pass, two matching networks. Wherein, LPF1, LPF2 and LPF3 are the low pass filter with cut-off frequency of 7GHz, 6GHz, 5GHz respectively; the HPF1, HPF2, and HPF3 are high-pass filters having cutoff frequencies of 6GHz, 5GHz, and 4GHz, respectively. Therefore, the LPF1 and the HPF1 can realize the passband 1 of 6-7 GHz after being integrated; the signal passing through the LPF1 passes through a circuit formed by integrating the LPF2 and the HPF2, and the 5-6 GHz pass band 2 can be realized; similarly, a 4-5 GHz pass band 3 can be realized; thus, the triplexer realizes three continuous pass bands of 4-5 GHz, 5-6 GHz and 6-7 GHz. The structure of realizing continuous pass bands by high-low pass cascade simplifies the design of a matching circuit and can be applied to the design of a multiplexer in an extension way. Notably, the port 1 is a common input port of three pass bands, and the signals in the pass bands output by the port 3 pass through one LPF (LPF 2) more than the signals output by the port 2; the signals in the pass band output by the port 4 pass through the LPF (LPF 3) more than the signals output by the port 3, so the pass band insertion loss from the pass band 1 to the pass band 3 is gradually increased.
In this triplexer design, the matching network only needs to match two adjacent filter impedances, which is the same as the matching principle of the duplexer. It is only necessary to achieve that the admittance sum of the input and output of the matching network is a constant close to 0. The admittance relation is calculated for the matching network 1 of fig. 2 as follows:
Y LPF1 ＝Y HPF1 +Y LPF2 (1)
wherein Y is LPF1 、Y HPF1 、Y LPF2 The input impedances of the three ports of the LPF1, HPF1, LPF2 connected to the matching network 1 are represented, respectively, and this formula is also applicable to the matching network 2.
In the embodiment, the suspended microstrip line has the characteristic of high quality factor Q, so that the insertion loss of the filter designed by the suspended microstrip line can be very small; in addition, the double-sided circuit structure of the suspended strip line can realize strong capacitance effect, so that the suspended microstrip line is the most convenient structure for designing the high-pass filter. But filters using suspended microstrip line designs require relatively large metal shielding boxes. Therefore, the substrate integrated suspended microstrip line technology can not only keep the advantages of the suspended microstrip line, but also conveniently realize the miniaturized integration of the circuit. However, the substrate integrated suspension microstrip line structure requires that the substrate layer of the middle suspension circuit is relatively thick to be hollowed out, which will limit the coupling amount between the capacitor plates of the double-sided circuit design.
The invention provides a substrate integrated suspended microstrip line structure with a circuit slotting structure, which comprises a first band-pass filter, a second band-pass filter and a third band-pass filter which adopt double-sided complete overlapping coupling, double-sided partial overlapping coupling and a single-sided circuit structure and are sequentially cascaded, wherein the input end of the first band-pass filter is connected with the input end of a triplexer, and the output ends of the first band-pass filter, the second band-pass filter and the third band-pass filter are respectively connected with the first output end, the second output end and the third output end of the triplexer.
The first band-pass filter comprises a first low-pass filter, a first matching network and a first high-pass filter; the input end of the first low-pass filter is connected with the input end of the triplexer, and the output end of the first low-pass filter is connected with the input end of the first matching network; the first output end of the first matching network is connected with the input end of the second band-pass filter, and the second output end of the first matching network is connected with the input end of the first high-pass filter; the output end of the first high-pass filter is connected with the first output end of the triplexer.
The second band-pass filter comprises a second low-pass filter, a second matching network and a second high-pass filter; the input end of the second low-pass filter is connected with the first output end of the first matching network, and the output end of the second low-pass filter is connected with the input end of the second matching network; the first output end of the second matching network is connected with the input end of the third band-pass filter, and the second output end of the second matching network is connected with the input end of the second high-pass filter; the output end of the second high-pass filter is connected with the second output end of the triplexer.
The third band-pass filter comprises a third low-pass filter and a third high-pass filter; the input end of the third low-pass filter is connected with the first output end of the second matching network, and the output end of the third low-pass filter is connected with the input end of the third high-pass filter; and the output end of the third high-pass filter is connected with the third output end of the triplexer.
The first low-pass filter, the second low-pass filter and the third low-pass filter all adopt the same low-pass filter circuit structure, and the low-pass filter circuit structure comprises an input port arranged on the upper side of the third layer of substrate, and a 6-order Chebyshev low-pass filter and an output port which adopt parallel open-circuit branches; the input port and the output port are both converted to the conductor line width of 50 omega by adopting step impedance; the 6-order Chebyshev low-pass filter adopts a cascade resonator structure, wherein a first-order resonator and second-order to sixth-order resonators which are linearly arranged are bent at 90 degrees.
The LPF adopts a Single-side circuit (Single side circuit) in figure 3, wherein the line width of a metal strip is w, the length and the width of an air cavity are a and b respectively, and the thickness of a substrate on which the strip line is positioned is h. Then at 0 < w/a<Under the condition of 1/2, the effective dielectric constant epsilon of the suspended microstrip line eff And a characteristic impedance Z 0 It can be expressed as:
wherein, the first and the second end of the pipe are connected with each other,
fig. 4 shows a two-port resonator consisting of a straight-through microstrip line connected in parallel with an open-circuited low-impedance microstrip line. The LC equivalent circuit model corresponding to the planar circuit in fig. 4 (a) is shown in fig. 4 (b), and the through microstrip line circuit can be equivalent to a series inductor L under the condition that the effective electrical length (L) is less than a quarter wavelength 1 And a parallel capacitor C 1 In which C is 2 ≈2C 1 The approximate value can be obtained by calculating the following formula (4) (5):
wherein f is c For low pass cut-off frequency, λ gc The guided wavelength (guided wavelength at the cut-off frequency) at the cut-off frequency.
When the effective electrical length of the open circuit part with the wire is less than a quarter wavelength, the equivalent capacitance can be directly derived as
The inductance value is relatively small as calculated by equation (5).
The transfer function of this structure is given in equation (7) for locating the transmission zero. The transmission zero equation of the resonator can be calculated from equation (8). It can be seen that the position of the transmission zero point is represented by L 3 And C 3 And (5) controlling. The zero point can then be precisely controlled by adjusting the values of m, s and l.
Wherein, the first and the second end of the pipe are connected with each other,
and performing frequency response simulation on the dual-port suspended microstrip circuit in the figure 4 by using IE3D electromagnetic simulation software. When the line length l of the series strip line, the line length s of the open-circuit microstrip line, and the line width m take different values, the frequency position change curve of the out-of-band zero point of the transmission function is shown in fig. 5.
According to the regular change of fig. 5, by cascading 6-order resonators, better out-of-band suppression and standing waves in the pass-band can be obtained. In order to realize the matching of real impedance at a port and reduce reflection loss, the input port and the output port adopt the conductor line width converted from step impedance to 50 omega; in order to be able to integrate with the high-pass filter in the next operation, the low-pass filter structure is bent by 90 °. According to the formula (8), setting the transmission zero values of the LPF1, LPF2 and LPF3 low-pass filters with the cut-off frequencies of 5GHz, 6GHz and 7GHz as 5.2GHz and 5.4GHz respectively; 6.2GHz, 6.5GHz, 7.3GHz and 7.5GHz, the circuit layout is as shown in 6, and the obtained dimensions are respectively as follows: l 11 ＝16.62,l 12 ＝21.35,d 11 ＝12.99,d 12 ＝9.16；l 11 ＝17.81, l 12 ＝21.96,d 11 ＝10.87,d 12 ＝7.52；l 11 ＝17.44,l 12 ＝18.10,d 11 ＝9.37,d 12 =6.28 (unit: mm), and then the planar circuits of the three low-pass filters were subjected to electromagnetic simulation and optimization, respectively, to obtain corresponding transmission and reflection function frequency responses as shown in fig. 7. As can be seen from the figure, the frequency response pass bands of LPF1, LPF2, and LPF3 are: DC-5GHz, DC-6GHz and DC-7 GHz, a plurality of transmission zeros are reasonably distributed in the stop band, the out-of-band inhibition degrees are all larger than 55dB, and the side band roll-off is all better than 300dB/GHz.
The first high-pass filter, the second high-pass filter and the third high-pass filter all adopt the same high-pass filter circuit structure, and the high-pass filter circuit structure comprises an input port arranged on the upper side of the third layer of substrate, an output port arranged on the lower side of the third layer of substrate and 9-order Chebyshev high-pass filters arranged on the upper side and the lower side of the third layer of substrate; the 9 th-order Chebyshev high-pass filter adopts a suspended microstrip double-sided coupling structure and comprises a first metal conduction band, a first narrow-band open stub, a second metal conduction band, a second narrow-band open stub and a third metal conduction band, wherein the first metal conduction band and the first narrow-band open stub are arranged on the upper side of a third layer substrate in a T-shaped manner; the first metal conduction band and the second metal conduction band, the fourth metal conduction band and the fifth metal conduction band are simultaneously arranged on the upper side and the lower side of the third layer of substrate to form an overlapped coupling structure, and cross-coupled lines are connected to the tail ends of the fourth narrow-band open-circuit stub and the fifth narrow-band open-circuit stub of non-adjacent branches.
The tail ends of the first narrow-band open stub, the second narrow-band open stub, the fourth narrow-band open stub and the fifth narrow-band open stub of the third high-pass filter are respectively connected with an open-ended branch structure of step impedance.
The invention realizes the introduction of transmission zero by loading a cross coupling structure between non-adjacent inductance wires of the high-pass filter, thereby realizing the response method of the generalized Chebyshev function filter. As shown in fig. 8, a conventional seven-order chebyshev HPF filter consists of three parallel inductors and four series capacitors, with the inductor being connected in parallel at L 1 And L 3 Cross coupling is introduced between the two to realize a generalized Chebyshev function HPF filter, wherein the cross coupling is C C To indicate.
In the design of a cross-coupled structure filter, it is important to distinguish the nature of the coupling between the resonator elements as magnetic coupling from electrical coupling, which is inherently due to the difference in phase shift to the signal, coupling between resonators being magnetic with a phase shift of-90 ° to the signal, and electrical coupling being +90 ° to the signal. General conditionsIn this case, the inductance implements magnetic field coupling, and the capacitance implements electric field coupling. For the out-of-band at the low frequency end of the high pass filter, the signal is given a +90 ° phase change by a capacitor and a-90 ° phase change by an inductor. The electrical coupling shown in FIG. 8 introduces a cross-coupled circuit configuration, with the signal passing through path C 2 -L 2 -C 3 The phase change is +90 ° -90 ° +90 ° =90 °, path L through cross coupling 1 -C C -L 3 The phase change is-90 ° +90 ° -90 ° = -90 °, and there is a phase difference of 180 ° between the two channels, so that a transmission zero is introduced in the stop band.
For the double-sided partial coupling circuit in fig. 1, the metal micro-strip is located on both sides of the substrate, and there is partial overlapping coupling between two layers of metal, if the circuit structure is a vertically symmetrical structure, the cross-sectional view is as shown in fig. 9, and the mutual coupling realized by the metal conduction bands of the upper and lower layers can be equivalent to a coupling capacitance effect. Therefore, the coupling capacitor of the double-sided partially overlapped circuit can be used for realizing the capacitor connected in parallel in the HPF circuit.
And (4) researching the coupling capacitance of the double-sided partially-overlapped circuit by using an odd-even mode impedance analysis method. The voltage of the upper conduction band of the substrate is set as + V, the voltage of the lower conduction band is-V, the voltage of the central plane (dotted line position) of the substrate is 0, the thickness of the substrate is h, t is the length of the overlapped part of the upper conduction band and the lower conduction band, and C p Front coupling capacitance for low radiation losses, C f The microstrip edge coupling capacitor with radiation loss is adopted.
By using the odd-mode impedance of the microstrip line, the capacitance value in the overlapping area of the suspended microstrip line can be calculated as follows:
wherein, C p ＞＞C f Therefore, the double-sided partially overlapped circuit capacitor C s ＝C f +C p Mu is the phase velocity of the electromagnetic wave in vacuum, epsilon eff Is the effective dielectric constant, Z ∞ The impedance of the odd mode of the equivalent microstrip line is expressed as follows:
in practical engineering applications, equation (11) is used to calculate the coupling capacitance.
Wherein epsilon r1 And ε 0 The dielectric constant of the plate and the vacuum dielectric constant, respectively.
According to the transmission line theory, under the constraint that the effective electrical length h of the conductor line is less than a quarter wavelength (the front view is shown as the conductor structure in 10), the input impedance of the narrow-side transmission line is equivalent to inductance, so that an open-circuit high-impedance line can be connected in series in the transmission line to introduce inductance when Z is c <<Z 0 When (wherein Z) c For the characteristic impedance of the introduced high-impedance line, Z 0 Characteristic impedance of transmission line), inductance value L in fig. 8 i (i =1, 2 or 3) and the high impedance line length h in fig. 10 H1 Satisfies the relation (12).
According to the analysis, the HPF filter adopts the upper and lower layers of overlapped metal conduction bands to realize the capacitance effect, and adopts the stub structure with open-circuit narrow sides connected in parallel to realize the parallel inductance. In order to improve the suppression performance, two steps are added to the structure shown in fig. 8, and a 9-order high-pass filter is designed. Firstly, according to capacitance/inductance values in Chebyshev prototypes, setting cut-off frequencies to be 6GHz, 5GHz and 4GHz respectively through equivalent calculation values of the capacitance/inductance of suspended microstrip lines in formulas (11) and (12), and setting transmission zero values to be 5.8GHz, 4.8GHz and 3.8GHz respectively to obtain a rough model of a planar structure; then, optimizing the rough model through electromagnetic simulation software to obtain a 9-order Chebyshev high-pass filter; finally, by means of the pair of high-pass filters proposed in fig. 8According to the cross coupling principle, a cross coupling line is connected to the tail end of a narrow-band open line, a transmission zero point is introduced, and the design of a generalized Chebyshev function high-pass filter is achieved. The final planar circuits corresponding to HPF1, HPF2, HPF3 are shown in fig. 10, where the yellow portion indicates that the circuit is on the G5 metal layer; the orange portion represents the circuit at the G6 level; the blue part indicates the presence of both G5 and G6 layers, belonging to the overlap coupling section. Because the HPF3 frequency band is lower, in order to reduce the whole volume of the circuit, the length of the HPF3 open-circuit branch is shortened by adopting a Stepped-impedance (Stepped-impedance) terminal open-circuit branch structure [10 ]][12]. The length of the cross-coupled lines determines the coupling strength and thus the position of the out-of-band transmission zero of the high pass filter, as will be explained in more detail below. FIG. 11 shows h in the HPF1, HPF2, and HPF3 planar circuits, respectively H1 ＝12.69mm、l H1 ＝12.73mm、 c H1 ＝1.00mm，h H2 ＝15.47mm、l H2 ＝15.74mm、c H2 ＝0.40mm，h H3 ＝15.61mm、 l H3 ＝23.20mm、c H3 Frequency response curve corresponding to 1.40 mm.
Also shown in FIG. 11, when cross-coupling in the HPF planar circuit configuration is from c H1 =1.00mm to c H1 =0.00mm from c H2 =0.60mm to c H2 =0.00mm from c H3 =2.10mm to c H3 And when the frequency is changed by =0.00mm, the transmission zero point is gradually far away from a change trend graph of the cut-off frequency until the transmission zero point disappears. As can be seen from the figure, when the cross-coupling line is shorter, the cross-coupling strength is weaker, and the transmission zero point is farther from the cutoff frequency of the passband; when the cross coupling is changed into 0, the transmission zero out of the passband disappears, the generalized Chebyshev response is changed into the Chebyshev response, and the out-of-band rejection becomes worse, so the introduction of the cross coupling line improves the out-of-band rejection of the filter transmission function. Based on the principle, in the process of designing the HPF, the position of a transmission zero point can be adjusted by adjusting the length of the cross-coupling line, so that the requirement of out-of-band rejection of the filter in actual engineering is met.
A band-pass filter can be formed by designing a matching stub to cascade the low-pass filter and the high-pass filter designed above. LPF1 and HPF1 cascade composition centerThe corresponding structure diagram is shown in fig. 12 for BPF1 with a frequency of 6.5 GHz. The same cascade of LPF2 and HPF2 constitutes BPF2 with a center frequency of 5.5GHz and BPF3 with a center frequency of 4.5GHz. BW (Bandwidth) BPF ＝f cHPF -f cLPF ，f oBPF ＝f cLPF +(f cHPF -f cLPF )/2＝f cHPF -(f cHPF -f cLPF ) /2, where BW denotes the bandwidth, f c Denotes the cut-off frequency, f o The center frequency is shown, so that the bandwidth and the center frequency of the BPF can be controlled through the designed cut-off frequencies of the LPF and the HPF, thereby realizing the design of the triplexers/multiplexers with different bandwidths and center frequencies, and uniformly designing the three BPF bandwidths of the triplexers to be 1GHz in the invention.
From the analysis of fig. 6 and 10, the three low-pass filters and the three high-pass filters are similar planar structures with different sizes, and when their sizes are as shown in table 1, the corresponding frequency responses are as shown in fig. 13 (a), 13 (b) and 13 (c), respectively.
According to the graph shown in fig. 13, each BPF has 2 transmission zeros at the low frequency, and a plurality of transmission zeros at the high frequency, so that the roll-off of the upper and lower sidebands is significantly improved, the roll-off of the sidebands is greater than 300dB/GHz, and the out-of-band rejection is greater than 50dB.
In fig. 12, the input and output ends of the three pass-band filters adopt a microstrip-stripline-suspended microstrip transition structure, and the microstrip line is partially provided with a line width H 1 The width of the edge is 2.00mm, and the planar input/output tap is convenient to integrate with an SMA connector or a front-stage circuit and a rear-stage circuit; linewidth H of strip line part 2 =0.38mm, spacer substrate width S =1.00mm; suspended stripline width H 3 =3.00mm. Therefore, the impedances of the microstrip line, the strip line and the suspended microstrip line are close to 50 omega, and the reflection loss is reduced by the path matching.
The width of the slot is W on the two sides of the BPF circuit with stronger radiation field s Air segment of =0.800mm, and the substrate is cut away in close proximity to the circuit to alter the magnetic field radiation of the circuit, thereby reducing the conductor loss of the circuit. Especially, in the LPF circuit, since the line width of a section of circuit equivalent to the inductor is narrow, the current density is large,conductor losses increase the insertion loss of the overall BPF. Especially, at the LPF1, which is a common part, at the input end, signals of all paths pass, so that the loss reduction at this position deteriorates the insertion loss of the triplexer for three pass bands.
In the 5-layer substrate, via holes with the radius of 0.15mm and 0.20mm are designed to be grounded in the edge area of the air cavity, so that the 5-layer circuit can be well grounded, and the integrity of the suspended microstrip air cavity is ensured. R 1 Via hole of =1.6mm, rivet for multilayer connection, R 2 And a via hole of =1mm is used for fixing the SMA connector.
In this embodiment, the first layer substrate is provided with one opening of the input microstrip line, the second layer substrate is provided with one opening of the input microstrip line and the substrate supporting bridge, the fourth layer substrate is provided with three openings of the output microstrip line and the substrate supporting bridge, and the fifth layer substrate is provided with three openings of the output microstrip line. Input end microstrip line taps are arranged at positions, corresponding to the openings of the first layer substrate and the second layer substrate, on the upper side of the third layer substrate, and output end microstrip line taps are arranged at positions, corresponding to the three openings of the fourth layer substrate and the fifth layer substrate, on the lower side of the third layer substrate.
The complete planar circuit of the Rogers5880 layers in the triplexer is shown in fig. 14, wherein the BPF1, BPF2, BPF3 circuits are distributed in the whole circuit as marked by red, blue, green line rectangular boxes respectively. The 3-D package structure of the whole 5-layer circuit is shown in fig. 15, in which the first layer substrate is provided with one opening of the microstrip line at the input end, the second substrate is provided with one opening of the microstrip line at the input end and a substrate supporting bridge, the fourth substrate is provided with three openings of the microstrip line at the output end and a substrate supporting bridge, and the fifth layer substrate is provided with three openings of the microstrip line at the output end. The front view of the G5 layer is shown in fig. 14 (a), the yellow portion is a conductor microstrip line, and includes a part of HPF circuit and a microstrip line tap at the output end; fig. 14 (b) shows a front view of the G6 layer, and the brown portion is a conductor microstrip line, including all the LPF circuits, a portion of the HPF circuits, and a microstrip line tap at the input end.
After the design of the 5-layer circuit is finished, the electromagnetic simulation software simulatesIs shown in FIG. 16, where S 21 The transmission function of the BPF1 is shown, the 3dB pass band is 4-5 GHz, and the transmission zero points close to the upper pass band and the lower pass band are distributed at 3.59GHz, 3.73GHz, 5.15GHz and 5.24GHz; s 31 The transmission function of the BPF2 is shown, the 3dB passband is 5-6 GHz, and the transmission zero points close to the upper and lower passbands are distributed at 4.46GHz, 4.87GHz, 6.22GHz and 6.31GHz; s 41 The transmission function of the BPF3 is shown, the 3dB pass band is 6-7 GHz, and the transmission zero points close to the upper pass band and the lower pass band are distributed at 5.40GHz, 5.81GHz, 7.28GHz and 7.48GHz. The out-of-band rejection degrees of the three pass bands are all larger than 50dB, and the pass band edge roll-off degree is larger than 210GHz/dB.
The triplexer is tested by using a vector network analyzer, and the test result is shown in fig. 17, the 3dB bandwidths of the three pass bands are 1GHz, the central frequencies are 4.5GHz, 5.5GHz and 6.5GHz respectively, the relative bandwidths are 22.22%, 18.18% and 15.38% respectively, the out-of-band rejection degree is greater than 50dB, the side-band roll-off is superior to 200dB/GHz, and the insertion losses of the three frequency bands are 1.7dB/1.5dB/1.4dB respectively. Firstly, documents of the continuous passband triplexer/multiplexer are less, and the continuous passband triplexer is realized by adopting a suspended microstrip line structure slotted along the edge of a circuit for the first time; secondly, the triplexer designed by the invention has obvious advantages of out-of-band suppression and in-pass insertion loss; finally, the slotted substrate suspension microstrip integrated waveguide triplexer fully utilizes a multilayer circuit board and the existing PCB processing technology, effectively overcomes the defects that the traditional waveguide suspension line circuit is large in size, high in weight, required to additionally machine a metal cavity, manually assembled and the like, and enables the dielectric integrated suspension line circuit to have the characteristics of low cost, small size, high integration level, self-packaging and the like.
The invention designs a broad band triplexer with a plurality of generalized Chebyshev function response channels with transmission zeros by adopting a substrate integrated waveguide suspension microstrip line structure slotted along the edge of a circuit. Firstly, a design method of a cross-coupled high-pass filter between non-adjacent narrow-band microstrip branches is provided, and the regulation and control of the position of transmission zero frequency are realized; the design of the multi-transmission zero low-pass filter is realized by adopting a parallel open-circuit branch knot mode. Then, the structure form of high and low filter cascade is adopted, so that the flexibility and adjustability of the pass band and the center frequency are convenient to realize, and the method can be popularized and applied to the design of continuous pass band multiplexers and discontinuous pass band multiplexers. And finally, the triplexer with the characteristics of high out-of-band rejection degree, small insertion loss, high integration level and the like is designed on the 5-layer circuit board, and the triplexer has a wide application prospect in a microwave circuit.
The principle and the implementation mode of the invention are explained by applying specific embodiments in the invention, and the description of the embodiments is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed, and in summary, the content of the present specification should not be construed as a limitation to the present invention.
It will be appreciated by those of ordinary skill in the art that the embodiments described herein are intended to assist the reader in understanding the principles of the invention and are to be construed as being without limitation to such specifically recited embodiments and examples. Those skilled in the art can make various other specific changes and combinations based on the teachings of the present invention without departing from the spirit of the invention, and these changes and combinations are within the scope of the invention.
Claims (4)
1. A broad band triplexer with continuous and same generalized Chebyshev function response channels is characterized by comprising five layers of substrates which are sequentially stacked and ten metal layers which are respectively arranged on the upper side and the lower side of the five layers of substrates; the middle parts of the second layer substrate and the fourth layer substrate are respectively provided with a first air cavity and a second air cavity, the upper side and the lower side of the third layer substrate are provided with a substrate integrated suspension microstrip line structure formed by high-low pass cascade band-pass filters, and the substrate integrated suspension microstrip line structure is grooved along the edge of a circuit;
the substrate integrated suspension microstrip line structure comprises a first band-pass filter, a second band-pass filter and a third band-pass filter which are sequentially cascaded and adopt a double-sided complete overlapping coupling, a double-sided partial overlapping coupling and a single-sided circuit structure, wherein the input end of the first band-pass filter is connected with the input end of the triplexer, and the output ends of the first band-pass filter, the second band-pass filter and the third band-pass filter are respectively connected with the first output end, the second output end and the third output end of the triplexer;
the first band pass filter comprises a first low pass filter, a first matching network and a first high pass filter; the input end of the first low-pass filter is connected with the input end of the triplexer, and the output end of the first low-pass filter is connected with the input end of the first matching network; a first output end of the first matching network is connected with an input end of the second band-pass filter, and a second output end of the first matching network is connected with an input end of the first high-pass filter; the output end of the first high-pass filter is connected with the first output end of the triplexer;
the second band-pass filter comprises a second low-pass filter, a second matching network and a second high-pass filter; the input end of the second low-pass filter is connected with the first output end of the first matching network, and the output end of the second low-pass filter is connected with the input end of the second matching network; a first output end of the second matching network is connected with an input end of the third band-pass filter, and a second output end of the second matching network is connected with an input end of the second high-pass filter; the output end of the second high-pass filter is connected with the second output end of the triplexer;
the third band-pass filter comprises a third low-pass filter and a third high-pass filter; the input end of the third low-pass filter is connected with the first output end of the second matching network, and the output end of the third low-pass filter is connected with the input end of the third high-pass filter; the output end of the third high-pass filter is connected with the third output end of the triplexer;
the first low-pass filter, the second low-pass filter and the third low-pass filter all adopt the same low-pass filter circuit structure, and the low-pass filter circuit structure comprises an input port arranged on the upper side of a third layer substrate, a 6-order Chebyshev low-pass filter adopting parallel open-circuit branches and an output port; the input port and the output port are both converted into conductor line widths of 50 ohms by adopting step impedance; the 6-order Chebyshev low-pass filter adopts a cascade resonator structure, wherein a first-order resonator is bent at an angle of 90 degrees with a second-order resonator to a sixth-order resonator which are linearly arranged;
the first high-pass filter, the second high-pass filter and the third high-pass filter all adopt the same high-pass filter circuit structure, and the high-pass filter circuit structure comprises an input port arranged on the upper side of the third layer of substrate, an output port arranged on the lower side of the third layer of substrate and 9-order Chebyshev high-pass filters arranged on the upper side and the lower side of the third layer of substrate; the 9-order Chebyshev high-pass filter adopts a suspended microstrip double-sided coupling structure and comprises a first metal conduction band, a first narrow-band open stub, a second metal conduction band, a second narrow-band open stub and a third metal conduction band, wherein the first metal conduction band and the first narrow-band open stub are arranged on the upper side of a third layer of substrate in a T-shaped manner; the first metal conduction band and the second metal conduction band, the fourth metal conduction band and the fifth metal conduction band are simultaneously arranged on the upper side and the lower side of the third layer substrate to form an overlapped coupling structure, and cross-coupled lines are connected to the tail ends of a fourth narrow-band open-circuit stub and a fifth narrow-band open-circuit stub of non-adjacent branches.
2. The generalized Chebyshev function response channel continuous tone broadband triplexer of claim 1 wherein the first, second, fourth and fifth narrowband open stubs of the third high-pass filter have their ends respectively switched into stepped-impedance open-ended stub structures.
3. The generalized Chebyshev function response channel continuous identical broadband triplexer according to claim 2, wherein the first layer substrate is provided with one opening of an input microstrip line, the second layer substrate is provided with one opening of an input microstrip line and a substrate supporting bridge, the fourth layer substrate is provided with three openings of an output microstrip line and a substrate supporting bridge, and the fifth layer substrate is provided with three openings of an output microstrip line.
4. The generalized Chebyshev function response channel continuous same broadband triplexer according to claim 3, wherein input microstrip line taps are arranged at positions corresponding to the openings of the first layer substrate and the second layer substrate on the upper side of the third layer substrate, and output microstrip line taps are respectively arranged at positions corresponding to the three openings of the fourth layer substrate and the fifth layer substrate on the lower side of the third layer substrate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110524331.5A CN113346205B (en) | 2021-05-13 | 2021-05-13 | Continuous same broadband triplexer of generalized Chebyshev function response channel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110524331.5A CN113346205B (en) | 2021-05-13 | 2021-05-13 | Continuous same broadband triplexer of generalized Chebyshev function response channel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113346205A CN113346205A (en) | 2021-09-03 |
| CN113346205B true CN113346205B (en) | 2023-02-03 |
Family
ID=77469690
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110524331.5A Active CN113346205B (en) | 2021-05-13 | 2021-05-13 | Continuous same broadband triplexer of generalized Chebyshev function response channel |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113346205B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113991269B (en) * | 2021-09-18 | 2022-07-12 | 天津大学 | Miniaturized high-harmonic-suppression dual-passband filter based on dielectric integrated suspension line |
| CN115275550B (en) * | 2022-08-24 | 2023-03-14 | 西安电子科技大学 | Miniaturized low insertion loss duplexer |
| CN115425940B (en) * | 2022-08-30 | 2023-07-04 | 北京邮电大学 | Construction method of microstrip multiplexer with continuous passband, microstrip multiplexer and device |
| CN115412043B (en) * | 2022-10-31 | 2023-01-24 | 成都科谱达信息技术有限公司 | Symmetrical lumped parameter low-pass filter for improving far-end rejection performance |
| CN117081542A (en) * | 2023-10-17 | 2023-11-17 | 中科海高(成都)电子技术有限公司 | Filter bank |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108598638A (en) * | 2018-04-13 | 2018-09-28 | 电子科技大学 | The multiplexer structure of suspended substrate stripline is integrated based on medium |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101778531B (en) * | 2010-02-23 | 2012-04-04 | 华为技术有限公司 | Integrated printed circuit board |
-
2021
- 2021-05-13 CN CN202110524331.5A patent/CN113346205B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108598638A (en) * | 2018-04-13 | 2018-09-28 | 电子科技大学 | The multiplexer structure of suspended substrate stripline is integrated based on medium |
Non-Patent Citations (1)
| Title |
|---|
| 《通道连续三工器关键技术研究》;龙之河;《中国优秀硕士学位论文全文数据库电子期刊》;20180815(第8期);正文第5章 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113346205A (en) | 2021-09-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113346205B (en) | Continuous same broadband triplexer of generalized Chebyshev function response channel | |
| Chen et al. | Design of miniaturized filtering power dividers for system-in-a-package | |
| KR102022579B1 (en) | A coupled line type of power divider with flexible bandwidth and out-of-band rejection performance | |
| CN109066039B (en) | Novel microstrip power division duplexer | |
| Sekar et al. | A novel compact dual-band half-mode substrate integrated waveguide bandpass filter | |
| Chen et al. | An evanescent-mode tunable dual-band filter with independently-controlled center frequencies | |
| TWI499121B (en) | A balanced wideband pass filter with a common mode signal is designed with a ground plane defect structure (DGS) and a similar open loop resonator (SRR) | |
| Lobato-Morales et al. | Dual-band multi-pole directional filter for microwave multiplexing applications | |
| Lee et al. | Metamaterial transmission line based bandstop and bandpass filter designs using broadband phase cancellation | |
| Farah et al. | A DESIGN OF COMPACT MICROWAVE DIPLEXER IN MICROSTRIP TECHNOLOGY BASED ON BAND-STOP FILTERS USING STEPPED IMPEDANCE RESONATOR | |
| Jung et al. | A highly selective UWB bandpass filter using stepped impedance stubs | |
| Velidi et al. | Design of compact microstrip diplexer with high selectivity | |
| CN113224491B (en) | Miniaturized broadband four-way filtering power divider based on non-equal-width three-wire coupling structure | |
| Lin et al. | Compact, shielded microstrip filter with high selectivity for 5G N78 application | |
| Han et al. | A compact planar ultra-wideband bandpass filter using cross-coupling SIR and defected ground structure | |
| He et al. | A dual-band bandpass filter based on hybrid structure of substrate integrated waveguide and substrate integrated coaxial line | |
| Hammed | Multilayered U-shape diplexer for high performance multifunctional wireless communication systems | |
| Farah et al. | A design of a compact microwave diplexer in microstrip technology based on bandpass filters using stepped impedance resonator | |
| CN115332755B (en) | Dual-frequency equal-division Gysel power division filter | |
| Safwat et al. | Dual bandstop resonator using combined split ring resonator and defected ground structure | |
| Dhwaj et al. | Microstrip diplexer with low channel-frequency ratio | |
| Wan et al. | A compact microstrip multi-layer bandstop filter using meandering transmission line structure | |
| Karimian et al. | Metamaterial stepped impedance resonator bandpass filter based on composite right/left-handed transmission lines | |
| Sun et al. | A compact bandpass filter with high selectivity and wide stopband | |
| Kerketta et al. | Dual Channel Diplexer based on Stepped Impedance Filter and Microstrip Open-Loop Resonator |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |