Coupler and radio frequency chip

Abstract

The utility model provides a coupler and a radio frequency chip, the coupler comprises a first microstrip line and a second microstrip line coupled with the first microstrip line, two ends of the first microstrip line are respectively provided with a radio frequency input port and an antenna output port, and two ends of the second microstrip line are respectively provided with an isolation port and a coupling output port; the coupler further comprises a first resistor, a first capacitor and a first inductor, the first end of the first inductor is connected with the isolation port, the second end of the first inductor is connected with the first end of the first resistor and the first end of the first capacitor, the second end of the first capacitor is grounded, and the second end of the first resistor is grounded. The coupler provided by the utility model can reduce tape-out times, reduce design difficulty, and improve debugging flexibility of the coupler.

Description

Technical Field

[0001] The utility model relates to the technical field of wireless communications, in particular to a coupler and a radio frequency chip. Background Art

[0002] As electronic devices evolve, their performance continues to improve, yet their size continues to shrink. Therefore, device miniaturization has become a hot topic. Couplers, as crucial components of RF front-end chips, require on-chip integration to achieve miniaturization. However, once designed, their performance becomes immutable. Therefore, the ability to adjust the performance of fabricated on-chip couplers is crucial.

[0003] Currently, for miniaturization, couplers in consumer electronic products are usually integrated into antenna switches (ASWs). In the ASW, the couplers transmit signals through coupling between traces. Figure 1 As shown, a signal is input through the RF input port. A portion of the signal is output directly from the antenna output port via a transmission line and transmitted to the antenna end for transmission. Another portion of the signal is coupled to the coupled output port and the isolated port via the transmission line. The signal at the coupled output port is monitored for energy at the coupled output, while the energy at the isolated port is dissipated by the resistor, resulting in poor control of the coupler's isolation system. Furthermore, according to the law of conservation of energy, the less energy dissipated by the isolated port's resistor, the greater the signal power received by the coupled output port, and the higher the monitoring accuracy.

[0004] However, since traditional design methods fully integrate all parts of the coupler within the ASW, the design cannot be modified once it is completed. The high cost of tape-out limits the number of design iterations, significantly increasing the design difficulty and, in turn, the cost. Utility Model Content

[0005] In view of the above deficiencies in the prior art, the present invention proposes a coupler and a radio frequency chip to solve the problems of poor isolation coefficient control effect and high cost of the prior coupler.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a coupler, comprising a first microstrip line and a second microstrip line coupled to the first microstrip line, wherein the first microstrip line is provided with an RF input port and an antenna output port at both ends, and the second microstrip line is provided with an isolation port and a coupling output port at both ends; the coupler also comprises a first resistor, a first capacitor and a first inductor, wherein the first end of the first inductor is connected to the isolation port, the second end of the first inductor is respectively connected to the first end of the first resistor and the first end of the first capacitor, the second end of the first capacitor is grounded, and the second end of the first resistor is grounded.

[0008] Preferably, the first microstrip line and the second microstrip line are respectively provided with a nickel-palladium-gold protective layer.

[0009] Preferably, the impedance of the first microstrip line is 50Ω.

[0010] Preferably, the impedance of the second microstrip line is 50Ω.

[0011] In a second aspect, the present invention provides a radio frequency chip, which includes the coupler as described above.

[0012] Compared to related technologies, in an embodiment of the present invention, the first microstrip line is provided with an RF input port and an antenna output port at each end, and the second microstrip line is provided with an isolation port and a coupling output port at each end; the first end of the first inductor is connected to the isolation port, the second end of the first inductor is connected to the first end of the first resistor and the first end of the first capacitor, respectively, the second end of the first capacitor is grounded, and the second end of the first resistor is grounded; by adjusting the first inductor and the first capacitor, the isolation coefficient of the coupler can be flexibly controlled without changing the coupling coefficient and insertion loss. In addition, the first inductor is generally small and can be wound around the substrate to reduce costs, occupying a small area and saving space. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention will be described in detail below with reference to the accompanying drawings. The above and other aspects of the present invention will become clearer and easier to understand through the detailed description made with reference to the following drawings.

[0014] Figure 1 Schematic diagram of the structure of a traditional coupler;

[0015] Figure 2 for Figure 1 Schematic diagram of simulation results of coupling coefficient and isolation coefficient;

[0016] Figure 3 for Figure 1 Schematic diagram of the simulation results of insertion loss;

[0017] Figure 4 This is a schematic structural diagram of a coupler according to an embodiment of the present utility model;

[0018] Figure 5 for Figure 4 Schematic diagram of simulation results of coupling coefficient and isolation coefficient;

[0019] Figure 6 for Figure 4 Schematic diagram of the simulation results of the insertion;

[0020] Figure 7 for Figure 4 Schematic diagram of simulation results of the coupling coefficient and isolation coefficient of the adjusted capacitance and inductance;

[0021] Figure 8 for Figure 4 Schematic diagram of the simulation results of the adjusted capacitance and inductance.

[0022] Among them, 100, coupler, 1, first microstrip line, 2, second microstrip line, 3, RF input port, 4, antenna output port, 5, coupled output port, 6, isolation port. DETAILED DESCRIPTION

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of the application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0024] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] Example 1

[0027] See also Figure 4 As shown, an embodiment of the present invention provides a coupler 100, the coupler 100 comprising a first microstrip line 1 and a second microstrip line 2 coupled to the first microstrip line 1, the first microstrip line 1 having an RF input port 3 and an antenna output port 4 at both ends, and the second microstrip line 2 having an isolation port 5 and a coupling output port 6 at both ends; the coupler 100 further comprises a first resistor R1, a first capacitor C1 and a first inductor L1, the first end of the first inductor L1 being connected to the isolation port, the second end of the first inductor L1 being connected to the first end of the first resistor R1 and the first end of the first capacitor C1, the second end of the first capacitor C1 being grounded, and the second end of the first resistor R1 being grounded. By adjusting the first inductor L1 and the first capacitor C1, the isolation coefficient of the coupler 100 can be flexibly controlled without changing the coupling coefficient and insertion loss. In addition, the first inductor L1 is generally small and can be wound around a substrate to reduce costs, occupying a small area and saving space.

[0028] In this embodiment, in order to better reflect the performance of the utility model, a traditional coupler is first simulated. The basic structure of the coupler is as follows: Figure 1 As shown in the simulation results, Figure 2 As shown. Usually, the performance of the coupler cannot be changed after the design is completed. If the measured performance does not meet the requirements, it needs to be redesigned, which will cost a lot of time and manpower. Therefore, the present invention adds a first inductor and a first capacitor after the isolation end of the coupler 100 to flexibly adjust the performance of the coupler 100 to achieve the design goal. In addition, as Figure 3 As shown in the figure, the insertion loss of the traditional coupler is simulated. It can be seen that the performance of the traditional on-chip coupler cannot be changed after the design is completed. If the measured performance cannot meet the requirements, it needs to be redesigned, which not only increases the product cost but also prolongs the product design cycle.

[0029] Secondly, the pad die reserved for the isolation port is connected to the substrate and a matching structure of a first inductor and a first capacitor is added to the substrate. By simulating the coupler 100, it can be seen that the basic structure of the coupler 100 is as follows: Figure 4 As shown in the simulation results, Figure 5As shown. The first capacitor C1 and the first inductor L1 resonate to flexibly adjust the isolation coefficient without affecting the coupling coefficient and insertion loss. The first capacitor C1 and the first inductor L1 resonate at the frequency point m1, and the first capacitor C1 and the first inductor L1 resonate at the frequency point m2. Figure 5 The simulation results show that the isolation can reach 45dB in the 2.3GHz-2.7GHz frequency band. This is a significant improvement compared to the traditional coupler 100. Figure 6 It can be seen from the simulation results that the insertion of the coupler is reduced compared with the traditional one.

[0030] Therefore, it can be seen from the figure that the coupler 100 with the matching structure of the first inductor L1 and the first capacitor C1 is simulated. From the simulation diagram, it can be seen that after the structure of the present invention is loaded at the isolation end, the coupling coefficient and insertion loss remain almost unchanged, and the isolation coefficient changes significantly.

[0031] If the current performance still cannot meet the requirements, the values ​​of the first inductor L1 and the first capacitor C1 can be changed. The simulation results after changing the values ​​of the first inductor L1 and the first capacitor C1 are as follows: Figure 7-Figure 8 As shown. Figure 5-Figure 6 and Figure 7-Figure 8 It can be seen that by changing the first inductor L1 and the first capacitor C1, the isolation coefficient of the on-chip coupler 100 can be flexibly controlled without changing the coupling coefficient and insertion loss. In addition, the first inductor L1 is usually small, and the cost can be reduced by winding the substrate.

[0032] In this embodiment, the first microstrip line and the second microstrip line are each provided with a nickel-palladium-gold protective layer. The surfaces of the first microstrip line and the second microstrip line are treated with nickel-palladium-gold to reduce their ohmic loss while improving their corrosion resistance and oxidation resistance.

[0033] Optionally, its power capacity needs to be considered. If the trace is too narrow, the maximum power it can withstand is lower. At the same time, the dielectric substrate of the microstrip line should use a low-loss high-frequency dielectric substrate suitable for its operating frequency.

[0034] In this embodiment, the impedance of the first microstrip line is 50Ω, which can reduce energy reflection at the port.

[0035] In this embodiment, the impedance of the second microstrip line is 50Ω, which can reduce energy reflection at the port.

[0036] Example 2

[0037] The present invention provides a radio frequency chip, which includes the coupler 100 of the first embodiment. The technical problems solved and the technical effects produced by the radio frequency chip are the same as those of the coupler 100, and are not described in detail here.

[0038] It should be noted that the various embodiments described above with reference to the accompanying drawings are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. Those skilled in the art should understand that any modifications or equivalent substitutions to the present invention that do not depart from the spirit and scope of the present invention are intended to be encompassed within the scope of the present invention. Furthermore, unless the context otherwise requires, words appearing in the singular include the plural form, and vice versa. Furthermore, unless otherwise specified, all or part of any embodiment may be used in combination with all or part of any other embodiment.

Claims

1. A coupler comprising a first microstrip line and a second microstrip line coupled to the first microstrip line, wherein the first microstrip line has a radio frequency input port and an antenna output port at both ends, and the second microstrip line has an isolation port and a coupling output port at both ends; characterized in that: The coupler further includes a first resistor, a first capacitor, and a first inductor. The first end of the first inductor is connected to the isolation port, the second end of the first inductor is respectively connected to the first end of the first resistor and the first end of the first capacitor, the second end of the first capacitor is grounded, and the second end of the first resistor is grounded.

2. The coupler according to claim 1, wherein The first microstrip line and the second microstrip line are respectively provided with a nickel-palladium-gold protective layer.

3. The coupler according to claim 1, wherein The impedance of the first microstrip line is 50Ω.

4. The coupler according to claim 1, wherein The impedance of the second microstrip line is 50Ω.

5. A radio frequency chip, characterized in that: The radio frequency chip includes the coupler according to any one of claims 1 to 4.

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