Output matching circuit and amplifier

Abstract

The present application provides an output matching circuit and an amplifier, wherein the output matching circuit includes a T-shaped artificial surface plasmon structure; the T-shaped artificial surface plasmon structure includes a filtering section and two transmission sections; the filtering section is provided with a first filtering unit, and the first filtering unit includes: a first groove and a first capacitor; and the two ends of the first capacitor are respectively connected to the two sides of the first groove. The technical solution provided by the present application solves the problem of high power consumption and inability to flexibly cope with various frequency harmonics in the harmonic suppression circuit in the prior art, thereby improving the harmonic suppression efficiency.

Description

Technical Field

[0001] This document relates to the field of amplifier technology, and in particular to an output matching circuit and an amplifier. Background Art

[0002] Harmonics are generally frequency-doubled components generated by the nonlinearity of the device. They are important index parameters that characterize the linearity of the amplifier and are one of the factors that affect the quality of the output signal.

[0003] The existing harmonic suppression method is: the amplifier circuit often uses an external filter in the output circuit to attenuate the harmonic component to achieve the effect of suppressing harmonics. It is usually divided into two types: active filter and passive filter.

[0004] However, the above method has the following problems: (1) Active filtering consumes additional power and is not suitable for scenarios with low power consumption requirements; (2) Passive LC device filtering is usually narrow-band, and the frequency of harmonics is relatively dispersed (especially for high-order harmonic components), making broadband filtering more difficult to achieve and the circuit more complex; (3) The filter loss is large, especially at millimeter waves or even higher frequencies, and the device loss rises rapidly with the increase of frequency; (4) The circuit cannot be adjusted according to the harmonic frequency. Summary of the invention

[0005] In view of the above analysis, the present application aims to provide an output matching circuit and an amplifier to solve at least one of the above problems.

[0006] In a first aspect, one or more embodiments of the present specification provide an output matching circuit, which is applied to an amplifier, wherein the output matching circuit comprises a T-shaped artificial surface plasmon structure; the T-shaped artificial surface plasmon structure comprises a filtering section and two transmission sections;

[0007] The filter section is provided with a first filter unit, the first filter unit comprising: a first groove and a first capacitor; and

[0008] Two ends of the first capacitor are respectively connected to two side surfaces of the first groove.

[0009] Furthermore, the first capacitor is a variable first capacitor.

[0010] Furthermore, the capacitance value of the first capacitor matches the capacitance value of the equivalent capacitor formed by the first groove.

[0011] Furthermore, the opening direction of the first groove is parallel to or perpendicular to the plane where the signal line is located.

[0012] Further, the first groove constitutes an equivalent first capacitor; and

[0013] The process dimensions corresponding to the capacitance value of the equivalent first capacitor include: the depth of the first groove, the inner wall spacing, the unit period and the outer wall length.

[0014] Furthermore, the filtering section includes a plurality of the first filtering units, and the plurality of first filtering units are connected in series to form a filtering network.

[0015] Further, the transmission section is provided with a plurality of second grooves; and

[0016] The plurality of second grooves are arranged according to the length of the groove sidewalls and in a preset order.

[0017] Furthermore, the output matching circuit further includes: a coplanar waveguide, and the coplanar waveguide is the output end of the output matching circuit.

[0018] In a second aspect, one or more embodiments of the present specification provide an amplifier, comprising: an input circuit, an amplifying device, and an output matching circuit as described in any one of the first aspects.

[0019] Further, the input circuit includes an artificial surface plasmon structure;

[0020] The artificial surface plasmon structure includes a gradient structure and a non-gradient structure;

[0021] A plurality of third grooves are arranged on the gradient structure;

[0022] The plurality of third grooves are arranged according to the length of the groove sidewalls and in a preset order;

[0023] The non-gradual structure is provided with a plurality of second filtering units;

[0024] The second filtering unit includes a second groove and a second capacitor; and

[0025] Two ends of the second capacitor are respectively connected to two side surfaces of the second groove.

[0026] Compared with the prior art, this application can at least achieve the following technical effects:

[0027] The present application uses a T-shaped artificial surface plasmon structure as the basis of the amplifier transmission circuit to reduce losses and filter out harmonic components. A first filtering unit containing a first capacitor is provided on the basis of the artificial surface plasmon structure, and the dispersion characteristics of the artificial surface plasmon structure are changed by changing the capacitance value of the first capacitor, thereby eliminating harmonics of various frequencies. In addition, the introduction of the first capacitor can further improve the low-pass filtering effect of the output matching circuit, thereby further enhancing the efficiency of filtering out harmonics. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate one or more embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0029] Figure 1 A top view of an output matching circuit provided for one or more embodiments of the present specification;

[0030] Figure 2 A schematic diagram of the structure of a first filtering unit and a second filtering unit provided for one or more embodiments of this specification;

[0031] Figure 3 A schematic diagram of the structure of a first groove provided for one or more embodiments of this specification;

[0032] Figure 4 An amplification circuit diagram provided for one or more embodiments of this specification;

[0033] Figure 5 A comparison of harmonic performance of the amplifier circuit when operating at 3.3 GHz when the capacitance value of the first capacitor provided in one or more embodiments of this specification is 0.5 pF and the capacitance value of the second capacitor is 0.1 pF;

[0034] Figure 6 A comparison of harmonic performance of the amplifier circuit when operating at 4.8 GHz is provided for one or more embodiments of the present specification when the capacitance value of the first capacitor is 0.2 pF and the capacitance value of the second capacitor is 0.1 pF. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the technical solutions in one or more embodiments of this specification, the following will be combined with the drawings in one or more embodiments of this specification to clearly and completely describe the technical solutions in one or more embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on one or more embodiments of this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this document.

[0036] An embodiment of the present application provides an output matching circuit, which is applied to an amplifier. The output matching circuit includes a T-shaped artificial surface plasmon structure; the T-shaped artificial surface plasmon structure includes a filtering section and two transmission sections; the filtering section is provided with a first filtering unit, and the first filtering unit includes: a first groove and a first capacitor; and the two ends of the first capacitor are respectively connected to the two side surfaces of the first groove.

[0037] In an embodiment of the present application, a typical power amplifier is usually composed of an input matching network, an amplifier device, a DC bias circuit and an output matching network. The input and output matching networks usually use transmission lines or LC resonant circuits to achieve impedance matching. The connection between the transmission line and the LC resonant circuit will cause power loss. And for the etched LC resonant circuit, the harmonic frequency filtered out cannot be adjusted according to actual conditions. Because the present application uses a T-shaped artificial surface plasmon structure to achieve wire-free connection, the power loss caused by the device connection is eliminated. At the same time, a first filtering unit containing a first capacitor is provided on the artificial surface plasmon structure, and by replacing different first capacitors, the artificial surface plasmon structure has different dispersion properties, thereby adapting to harmonics of different frequencies.

[0038] Specifically, if Figure 1 As shown, the T-shaped artificial surface plasmon structure includes: a filter section A and two transmission sections B. The filter section A is provided with a first filter unit, and a plurality of first filter units are connected in series to form a filter network. The first filter unit includes: a first groove and a first capacitor; the two ends of the first capacitor are respectively connected to the two side surfaces of the first groove. The opening direction of the first groove is parallel to the plane where the signal line is located.

[0039] The horizontal direction of transmission section B is a gradual structure. The gradual structure means that the side wall length of each groove in the horizontal direction of transmission section B changes according to a preset rule to achieve impedance, wave number and mode matching from surface waveguide to artificial surface plasmon. The vertical direction of transmission section B includes a gradual structure and a non-gradual structure. The non-gradual structure is derived from the filter section A.

[0040] In addition, the output matching circuit further includes a coplanar waveguide C, which is the output end of the output matching circuit.

[0041] It should be noted that the first capacitor can be embedded in the first groove. Figure 2 As shown, the first capacitor is connected to the two sides of the first groove using a wire. By adjusting the capacitance value of the first capacitor, harmonics of different frequencies can be eliminated. The opening direction of the first groove is parallel to the plane where the signal line is located, so as to facilitate the integration of the output matching circuit onto the circuit board. However, in actual scenarios, the opening direction of the first groove can also be perpendicular to the plane where the signal line is located.

[0042] Preferably, the transmission section B includes a plurality of second grooves; the plurality of second grooves are arranged in a preset order. Figure 1 As shown, the second grooves on the right side of the transmission section B are arranged from large to small according to the length of the groove side wall, and the second grooves below the transmission section B are arranged from large to small according to the length of the groove side wall.

[0043] Preferably, in the embodiment of the present application, the first capacitor of the present application is a variable first capacitor. By setting a variable first capacitor, when eliminating harmonics of different frequencies, it is not necessary to replace the first capacitor of the corresponding capacitance value, but only to adjust the capacitance value of the variable first capacitor.

[0044] Preferably, in an embodiment of the present application, the capacitance value of the first capacitor matches the capacitance value of the equivalent capacitance formed by the first groove. Since the first groove itself is equivalent to a capacitor, the capacitance value of the first capacitor should match the capacitance value of the equivalent capacitance formed by the first groove, otherwise the filtering effect will be reduced. Specifically, the capacitance value of the first capacitor and the capacitance value of the equivalent capacitance formed by the first groove are of the same order of magnitude. For example, if the capacitance value of the equivalent capacitance formed by the first groove is in the pF level, then the capacitance value of the first capacitor is also in the pF level. Correspondingly, for the variable first capacitor, the range of variation of its capacitance value is in the pF level.

[0045] In the embodiment of the present application, the equivalent capacitance of the first groove is related to the size of the first groove. Specifically, the process dimensions corresponding to the capacitance value of the equivalent first capacitor include: the depth h of the first groove, the inner wall spacing a, the unit period p and the outer wall length w, such as Figure 3 shown.

[0046] The present application embodiment provides an amplifier, such as Figure 4 As shown, it includes: an input circuit 1, an amplifier device 2 and an output matching circuit 3 as described in any of the above embodiments.

[0047] In an embodiment of the present application, the input circuit 1 includes an artificial surface plasmon structure; the artificial surface plasmon structure includes a gradual structure and a non-gradual structure; a plurality of third grooves are arranged on the gradual structure; the plurality of third grooves are arranged according to the length of the groove sidewalls and a preset order; the non-gradual structure is provided with a plurality of second filtering units; the second filtering unit includes a second groove and a second capacitor; and the two ends of the second capacitor are respectively connected to the two sides of the second groove. Among them, the side wall length of each groove in the gradual structure changes according to a preset rule to achieve the matching of impedance, wave number and mode from the surface waveguide to the artificial surface plasmon. In order to further improve the filtering effect of the output circuit, a capacitor is also provided in the second filtering unit of the input circuit 1. In actual scenarios, the capacitor can be adjusted to enhance the filtering effect of the output circuit. In addition, artificial surface plasmons are used to replace part of the line connection of the input circuit to further reduce the power consumption of the amplifier.

[0048] It should be noted that the amplifier device 2 is usually a transistor, and those skilled in the art should know that the transistor can be replaced by other devices with an amplification function. The second capacitor can be embedded in the second groove, such as Figure 2 shown.

[0049] In order to illustrate the feasibility of the above technical solution, the following examples are given in the embodiments of the present application:

[0050] The transmission line in this example is a coplanar waveguide, and can also be other types of TEM mode transmission lines with an impedance of 50 ohms. The grounding structure uses a structure similar to the Vivaldi antenna (a slot microstrip antenna that uses an exponential slot structure to control electromagnetic waves to radiate electromagnetic energy from one end of the slot to the open end).

[0051] In this example, the dielectric substrate is Rogers 4003C, with a dielectric constant of 3.3, a loss angle of 0.0027, and a thickness of 1.5 mm. In actual scenarios, other substrates of the same type can be selected according to specific requirements.

[0052] The input matching circuit is designed as follows:

[0053] Coplanar waveguide: The signal line and ground line spacing is 0.25mm, the signal line width is 2.3mm, the ground line width is 24.2mm, and the maximum length of the ground line is 44.18mm. The gradient structure uses 7 artificial surface plasmon structures with gradient groove wall lengths on the signal line. The groove wall lengths are 1.8mm, 2.35mm, 2.95mm, 3.62mm, 4.38mm, 5.15mm, and 6.40mm from left to right. The unit period of the second filter unit with a non-gradient structure is 5.5mm, the outer wall width is 8.8mm, the groove depth is 6.8mm, and the inner wall spacing is 2.6mm. The number of periodic units is 7, and the capacitance value of the second capacitor varies from 0.1pF to 0.5pF.

[0054] The output matching circuit is designed as follows:

[0055] The unit period of the first filter unit in the filter section is 5.5mm, the outer wall width is 6.7mm, the groove depth is 5.5mm, and the inner wall spacing is 1.0mm. The number of periodic units is 15, and the capacitance value of the first capacitor varies from 0.1pF to 0.5pF. In the horizontal direction of the transmission section, an artificial surface plasmon structure with 8 groove walls with gradient changes is used on the signal line. The groove walls are 1.07mm, 1.52mm, 2.03mm, 2.59mm, 3.20mm, 3.85mm, 4.53mm and 5.25mm from right to left. Coplanar waveguide: The size of the signal line and the ground line spacing is 0.15mm, the signal line width is 1.4mm, the ground line width is 24.2mm, and the maximum length of the ground line is 44.18mm.

[0056] The vertical direction of the transmission section includes a gradient structure and a non-gradient structure. The non-gradient structure is vertically drawn from the 9th periodic unit position of the filter section. The unit period of the periodic unit of the non-gradient structure is 5.5mm, the outer wall width is 5.3mm, the groove depth is 3.6mm, the inner wall spacing is 1.7mm, and the number of periodic units is 6. The groove walls of the gradient structure are 3.28mm, 2.71mm, 2.30mm and 1.98mm from top to bottom.

[0057] The DC bias of amplifier devices (such as transistors, field effect transistors, etc.) can be integrated on the PCB substrate or independently provided with power supply outside the substrate.

[0058] Based on the amplifier circuit in the example, the capacitance value of the first capacitor is set to 0.5pF, the capacitance value of the second capacitor is set to 0.1pF; the capacitance value of the first capacitor is set to 0.2pF, and the capacitance value of the second capacitor is set to 0.1pF; to obtain the harmonic performance curve of the corresponding amplifier circuit, and compare it with the control group. The comparison results are as follows Figure 5 and Figure 6 As shown in FIG. 1 , the amplifier circuit in the control group uses a transmission line as the output circuit of the discharge circuit.

[0059] Depend on Figure 5 and Figure 6 It can be seen that due to the adjustment of the dispersion characteristics of artificial surface plasmons by capacitors, the operating frequency of the amplifier circuit can be reconfigured, that is, the filter network can cope with harmonics of various frequencies by adjusting the capacitance value. Compared with the conventional transmission line matching method, the harmonic components of the amplifier circuit using artificial surface plasmons as the output filter network are significantly suppressed.

[0060] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0061] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0062] The above description is only an embodiment of this document and is not intended to limit this document. For those skilled in the art, this document may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this document should be included in the scope of the claims of this document.

Claims

1. An output matching circuit, applied to an amplifier, characterized in that: The output matching circuit includes a T-shaped artificial surface plasmon structure; the T-shaped artificial surface plasmon structure includes a filtering section and two transmission sections; One of the transmission sections is led out from the end of the filtering section, and the other transmission section is led out from the middle of the filtering section; The filter section is provided with a plurality of first filter units of the same shape and size, each of the first filter units comprising: a first groove and a first capacitor; and Two ends of the first capacitor are respectively connected to two side surfaces of the first groove; The first capacitor is a variable first capacitor.

2. The circuit according to claim 1, characterized in that The capacitance value of the first capacitor matches the capacitance value of the equivalent capacitor formed by the first groove.

3. The circuit according to claim 1, characterized in that The opening direction of the first groove is parallel to or perpendicular to the plane where the signal line is located.

4. The circuit according to claim 3, characterized in that The first groove constitutes an equivalent first capacitor; and The process dimensions corresponding to the capacitance value of the equivalent first capacitor include: the depth of the first groove, the inner wall spacing, the unit period and the outer wall length.

5. The circuit according to claim 1, characterized in that The filtering section includes a plurality of the first filtering units, and the plurality of the first filtering units are connected in series to form a filtering network.

6. The circuit according to claim 1, characterized in that The transmission section is provided with a plurality of second grooves; and The plurality of second grooves are arranged according to the length of the groove sidewalls and in a preset order.

7. The circuit according to claim 1, characterized in that The output matching circuit further includes: a coplanar waveguide, and the coplanar waveguide is the output end of the output matching circuit.

8. An amplifier, characterized in that: include: An input circuit, an amplifier device, and an output matching circuit as claimed in any one of claims 1 to 7; The input circuit is an artificial surface plasmon structure.

9. The amplifier according to claim 8, characterized in that The artificial surface plasmon structure includes a gradient structure and a non-gradient structure; A plurality of third grooves are arranged on the gradient structure; The plurality of third grooves are arranged according to the length of the groove sidewalls and in a preset order; The non-gradual structure is provided with a plurality of second filtering units; The second filtering unit includes a second groove and a second capacitor; as well as Two ends of the second capacitor are respectively connected to two side surfaces of the second groove.

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