HIGH-FREQUENCY AMPLIFIER AND ADJUSTING CIRCUIT

Abstract

A high-frequency amplifier is disclosed, comprising an input matching circuit, an output matching circuit, and m (m is an integer greater than or equal to three) gain elements (1), wherein at least one of the input and output matching circuits comprises: a comb structure (30) with m lines, one end of which is connected one-to-one to the m gain elements, and a connecting part (3f) in which the other ends of the m lines are connected to each other; and resistors (4) provided between adjacent lines of the m lines, and wherein several gaps formed between adjacent lines of the m lines comprise a first gap (L1) and a second gap (L2) greater than the first gap.

Description

TECHNICAL AREA

[0001] The present disclosure relates to a high-frequency amplifier and an matching circuit. STATE OF THE ART

[0002] A high-frequency amplifier described in patent literature 1 comprises a gain element, an input matching circuit provided on one input side of this gain element, and an output matching circuit provided on one output side of this gain element. In this high-frequency amplifier, a slot is provided in the input matching circuit to reduce amplitude and phase differences in a high-frequency signal applied to each cell of the gain element. Furthermore, in this high-frequency amplifier, the isolation between the cells of the gain element is improved by inserting a resistor in the slot, and oscillations are suppressed. REFERENCE LISTPATENT LITERATURE

[0003] Patent Literature 1: JP 2010-219654 A SUMMARY OF THE INVENTIONAL PROBLEM

[0004] In the high-frequency amplifier described in patent literature 1, if the aforementioned slot is narrow, and a high-frequency current flows in opposite directions between the two ends of the input matching circuit, between which the slot is enclosed, coupling occurs across the slot, and the high-frequency current flows through this coupling. In this case, a current path (loop) is formed in this high-frequency amplifier through which the high-frequency current flows between the input matching circuit, the amplifying element, and the output matching circuit.

[0005] Since the high-frequency current in this flow channel does not flow through the resistor located in the slot, but rather through the coupling mentioned above, the high-frequency current is not attenuated, even though the resistor is located in the slot. Consequently, there is a possibility that the high-frequency current is amplified by the amplifying element, causing the high-frequency amplifier to oscillate. Therefore, increasing the slot width can be considered as a method to suppress such oscillation.

[0006] To transform a high-frequency amplifier into a high-performance amplifier, the impedances of the amplifier stage and the matching circuits (input and output matching circuits) must be reduced. However, increasing the slot width in the input matching circuit of the aforementioned high-frequency amplifier results in a high input matching impedance. More precisely, in the conventional high-frequency amplifier mentioned above, there are limits to how far the impedances of the matching circuits can be reduced while still suppressing oscillations.

[0007] The aim of the present disclosure is to provide a high-frequency amplifier that can implement both the suppression of vibrations and impedance reduction in matching circuits. SOLUTION TO THE PROBLEM

[0008] A high-frequency amplifier according to the present disclosure comprises an input matching circuit, an output matching circuit and m (m is an integer greater than or equal to three) amplifying elements, wherein at least one of the input and output matching circuits comprises: a comb structure with m lines, one end of which is connected one-to-one to the m amplifying elements, and a connecting part at which the other ends of the m lines are connected to each other; and resistors provided between adjacent lines of the m lines, and several gaps formed between adjacent lines of the m lines, comprising a first gap and a second gap greater than the first gap. ADVANTAGEOUS EFFECTS OF THE INVENTION

[0009] According to the present disclosure, it is possible to achieve both the suppression of vibrations and an impedance reduction in the matching circuits through the configuration described above. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a view showing an example (m=4) of the configuration of a high-frequency amplifier according to embodiment 1; Fig. Figure 2 is a view that explains an advantageous effect of the high-frequency amplifier according to embodiment 1; Fig. Figure 3 is a view that explains the advantageous effect of the high-frequency amplifier according to embodiment 1; Fig. Figure 4 is a view that provides an example of comparing the fluxes of high-frequency currents in a conventional high-frequency amplifier with those in Fig. 2 shows; Fig. Figure 5 is a view that provides an example of comparing the currents in the conventional high-frequency amplifier with those in Fig. 3 shows; Fig. Figure 6 is a view showing an example of a configuration in which lines in the high-frequency amplifier are eliminated according to embodiment 1; Fig. Figure 7 is a view showing another example of the configuration of the high-frequency amplifier in embodiment 1; Fig. Figure 8 is a view showing another example (m=3) of the configuration of the high-frequency amplifier in embodiment 1; Fig. 9 is a view that suggests a beneficial effect of the in Fig. The high-frequency amplifier shown in section 8 is explained; Fig. Figure 10 is a view that provides an example of a comparison of the flow of high-frequency currents in a conventional high-frequency amplifier with those in Fig. The 8 currents shown are shown; Fig. 11 is a view showing an example of a configuration where the lines in the high-frequency amplifier are made of Fig. 8 have been eliminated; Fig. 12 is a view that provides another example of the configuration of the in Fig. The high-frequency amplifier shown in section 8 is shown; Fig. Figure 13 is a view showing another example (m=5) of the configuration of the high-frequency amplifier in embodiment 1; Fig. Figure 14 is a view that provides an example of the fluxes of high-frequency currents in the Fig. The 8 high-frequency amplifiers shown are shown; and Fig. Figure 15 is a view illustrating an example of the configuration of a high-frequency amplifier according to embodiment 2. DESCRIPTION OF THE EXAMPLES OF EXECUTION

[0010] The exemplary embodiments of the present disclosure are explained in detail below with reference to the drawings. Example 1.

[0011] Fig. Figure 1 is a view showing an example of the configuration of a high-frequency amplifier according to embodiment 1. The high-frequency amplifier according to embodiment 1 comprises amplification elements 1, lines or wires 2, and a transmission line 3, as shown in Fig. 1 shown. Although in Fig. 1 a configuration on the side of an output port (designated by reference numeral 6 in Fig. 1) The high-frequency amplifier is shown as an example; an input terminal (not shown) of the high-frequency amplifier can also be configured in the same way as in Fig. 1 shown and viewed.

[0012] The amplifying elements 1 each amplify a high-frequency current that is fed in from the input terminal of the high-frequency amplifier and comprise, for example, a transistor or a field-effect transistor. In the high-frequency amplifier according to embodiment 1, m (m is an integer greater than or equal to three) amplifying elements 1 are provided. Fig. Figure 1 shows an example with four reinforcement elements 1 (m=4).

[0013] The lines or wires 2 are thin metal wires that connect an output terminal of each of the four amplifying elements 1 and an end of a corresponding line 3a, 3b, 3c and 3d that form the transmission line 3.

[0014] The transmission line 3 is formed on a dielectric plate provided at the output terminal sides of the amplifying elements 1 and forms an output matching circuit provided at the output terminal sides of the amplifying elements 1. In Fig. For the sake of simplicity, the representation of the dielectric plate is omitted and only the transmission line 3 formed on this dielectric plate is shown.

[0015] The transmission line 3 comprises: a comb structure 30 with the four parallel lines 3a, 3b, 3c and 3d and a connecting part 3f; and resistors 4, which are provided between adjacent lines of the four lines, as shown in Fig. 1 shown.

[0016] The ends of the four conductors 3a, 3b, 3c and 3d are connected one-to-one to the four reinforcing elements via the wires 2, as shown in Fig. 1 shown. In addition, the other ends of the four lines 3a, 3b, 3c and 3d are connected together to form the connecting part 3f.

[0017] Furthermore, in the transmission line 3 several distances are formed between adjacent lines of the four lines 3a, 3b, 3c and 3d, each comprising a first distance L1 and second distances L2 that are greater than the first distance L1.

[0018] In transmission line 3, for example, each of the line pairs is formed by taking two adjacent lines from the four lines mentioned above and connecting them sequentially from one end of the transmission line along an upward or downward direction. Fig. 1. They can be combined, i.e., in a direction where the lines are arranged side by side. In Fig. For example, in transmission line 3, lines 3a and 3b form a line pair 3ab, and lines 3c and 3d form a line pair 3cd.

[0019] Furthermore, in transmission line 3, the distance between the conductor pairs in the upward or downward direction of the Fig. 1, i.e., the direction in which the conductors are arranged side by side, is the first distance L1, and the distance between the conductors that each of the conductor pairs forms in that direction is the second distance L2, which is greater than the first distance L1. In Fig. For example, the distance between the wire pairs 3ab and 3cd is the first distance L1, and the distance between the wires 3a and 3b as well as the distance between the wires 3c and 3d are the second distances L2.

[0020] Although in Fig. While the example shown in Figure 1 shows that the second distances L2 formed at the two positions are nearly identical, the second distances L2 need not necessarily be identical. For example, the second distances L2 formed at the two positions can be different, as long as all second distances L2 formed at the two positions are wider than the first distance L1. However, it is desirable that the second distances L2 be wide enough to at least prevent electrical coupling between the conductors that form each of the second distances L2.

[0021] Next, an advantageous effect of the high-frequency amplifier according to embodiment 1 will be described with reference to the Fig. 2 and Fig. 3 explained.

[0022] Fig. Figure 2 shows a case in which the amplifying element 1, which is connected to the outermost line 3a of the four amplifying elements 1, operates in the opposite phase, while the amplifying elements 1 connected to the other lines 3b, 3c, and 3d operate in the same phase. In this case, a high-frequency current in the transmission line 3 with the opposite phase (in the opposite direction) is applied only to line 3a from amplifying element 1.

[0023] The above-mentioned condition, in which one of the amplifying elements 1 operates with an opposite phase, can occur, for example, when a signal with a noise component whose phase changes randomly is input into an input terminal of an input matching circuit (not shown).

[0024] In Fig. 2. It is assumed that the direction of the high-frequency current with the opposite phase (the opposite direction) applied from the amplifying element 1 to line 3a is from right to left, and the direction of the high-frequency currents with the same phase applied from the amplifying elements 1 to lines 3b, 3c, and 3d is from left to right. Fig. 2 are the in-phase high-frequency currents flowing from the amplifying elements 1 to the lines 3b, 3c and 3d, indicated by thin arrows. In Fig. For the sake of simplicity, the representation of the reinforcing elements 1 and the wires 2 is omitted.

[0025] Since the second distance L2 is formed in transmission line 3 between lines 3a and 3b, which is sufficiently large to at least prevent electrical coupling between lines 3a and 3b, no coupling occurs between these lines in this case. Therefore, a high-frequency current applied to line 3b flows through the resistor 4 provided between lines 3a and 3b into line 3a, as indicated by a broad arrow in Fig. 2 is shown, and is damped because it flows through this resistor 4. Therefore, in the high-frequency amplifier, the high-frequency current is damped and oscillations are suppressed.

[0026] Even if slight coupling occurs between lines 3a and 3b, the high-frequency current applied to line 3b flows through the resistor 4 between the lines into line 3a, instead of flowing through the coupling point mentioned above, if the impedance of the resistor 4 between these lines is lower than the impedance between the lines at the point of coupling. Therefore, the high-frequency current is attenuated in the high-frequency amplifier, and the oscillations are suppressed in this case as well.

[0027] Furthermore, a case is considered in which a circulating current path (loop) is formed in which part or all of the high-frequency current applied to line 3b does not flow through the resistor 4 provided between lines 3a and 3b, but through the coupling point mentioned above into line 3a and then through the amplifying element 1 and the input matching circuit and is applied again to line 3b of the output matching circuit (transmission line 3).

[0028] In this case, the amplified high-frequency current applied to line 3b flows through the resistor 4 between lines 3b and 3c into line 3c, as indicated by a broad arrow in Fig. Figure 2 shows the high-frequency current flowing into line 3c. Furthermore, the high-frequency current flows from line 3c through resistor 4, which lies between lines 3c and 3d, into line 3d.

[0029] As already mentioned, the high-frequency current applied to line 3b flows through the resistors 4 into the adjacent lines (lines 3c and 3d) and is thereby attenuated. Therefore, in the high-frequency amplifier according to embodiment 1, even if a circulating current path (loop) is formed as above, the increase of the high-frequency current can be prevented and oscillations suppressed.

[0030] Fig. Figure 3 shows a case in which the amplifier 1 connected to line 3b of the four amplifiers 1 operates with an opposite phase, while the amplifiers 1 connected to the other lines 3a, 3c, and 3d operate with the same phase. In this case, a high-frequency current with the opposite phase is applied in transmission line 3 only to line 3b from amplifier 1.

[0031] Also in Fig. 3. It is assumed that the direction of the high-frequency current with the opposite phase (the opposite direction) applied from the amplifying element 1 to line 3b is from right to left, and the direction of the high-frequency currents with the same phase applied from the amplifying elements 1 to lines 3a, 3c and 3d is from left to right, as in Fig. 2. In Fig. For the sake of simplicity, the representation of the reinforcing elements 1 and the wires 2 is omitted in Figure 3.

[0032] Since the second distance L2 is formed in transmission line 3 between lines 3a and 3b, which is sufficiently large to at least prevent electrical coupling between lines 3a and 3b, no coupling occurs between these lines in this case. Therefore, a high-frequency current applied to line 3a flows through the resistor 4, which is provided between lines 3a and 3b, into line 3b, as indicated by a broad arrow in Fig. 3 is shown, and is damped because it flows through this resistor 4. Therefore, in the high-frequency amplifier, the high-frequency current is damped and oscillations are suppressed.

[0033] Even if slight coupling occurs between lines 3a and 3b, the high-frequency current applied to line 3a flows through the resistor 4 between the lines into line 3b, instead of flowing through the coupling point mentioned above, if the impedance of the resistor 4 between these lines is lower than the impedance between the lines at the point of coupling. Therefore, in the high-frequency amplifier, the high-frequency current is attenuated and the oscillations are suppressed in this case as well.

[0034] However, if we consider lines 3b and 3c, the first distance L1 formed between them is smaller than the second distances L2, which are the distances between the lines forming the pair. Therefore, electrical coupling between lines 3b and 3c is possible.

[0035] If coupling occurs between lines 3b and 3c, a high-frequency current applied to line 3c does not flow through the resistor 4 provided between lines 3b and 3c, but rather through the coupling point mentioned above into line 3b. In this case, a loop can be formed in the high-frequency amplifier, in which the high-frequency current applied to line 3c flows through the coupling point mentioned above into line 3b, then passes through the amplifying element 1 and the input matching circuit, and is applied again to line 3c of the output matching circuit (transmission line 3).

[0036] However, since the amplified high-frequency current applied to line 3c also flows through the resistor 4 between lines 3c and 3d into line 3d, as indicated by a broad arrow in Fig. As shown in Figure 3, the high-frequency current is attenuated by this resistor 4. Therefore, the rise of the high-frequency current can be prevented in the high-frequency amplifier, and oscillations can also be suppressed in this case.

[0037] Furthermore, in the high-frequency amplifier according to embodiment 1, not only the second distance L2, but also the first distance L1, which is narrower than the second distance, is formed by the lines 3b and 3c, as shown in the Fig. 2 and Fig. Figure 3 shows that in the high-frequency amplifier according to embodiment 1, a further impedance reduction is also achieved in the transmission line 3 compared to the case where all distances are equal to the second distances L2. More precisely, in the high-frequency amplifier according to embodiment 1, it is possible to achieve both the suppression of oscillations and an impedance reduction in the matching circuits (the input and output matching circuits).

[0038] The advantageous effect of the high-frequency amplifier according to embodiment 1 is demonstrated here by means of the Fig. 4 and Fig. 5 is explained in more detail. Fig. Figure 4 shows an example comparing the flow of high-frequency currents in a conventional high-frequency amplifier with those in Fig. 2. Fig. Figure 5 shows an example comparing the high-frequency currents in the conventional high-frequency amplifier with those in Fig. 3 streams shown.

[0039] In the Fig. 4 and Fig. Reference numeral 5 denotes a transmission line contained in the conventional high-frequency amplifier. This transmission line 20 comprises: a comb structure 200 with four parallel lines 20a, 20b, 20c and 20d and a connecting part 20f; and resistors 21, each provided between adjacent lines of the four lines, as in the transmission line 3 in embodiment 1.

[0040] The ends of the four lines 20a, 20b, 20c, and 20d are connected one-to-one via wires 2 (not shown) to four amplifier elements (not shown). Furthermore, the other ends of the four lines 20a, 20b, 20c, and 20d are connected together to form the connecting section 20f. Reference numeral 26 also designates an output terminal of the conventional high-frequency amplifier.

[0041] In transmission line 20, all distances between the lines are essentially the same, unlike in transmission line 3 in embodiment 1. Furthermore, in transmission line 20, all distances between the lines are smaller than the second distances L2 mentioned above.

[0042] In the Fig. In the transmission line 20 shown in Figure 4, for example, only line 20a is supplied with a high-frequency current with the opposite phase by a gain element 1. Since the distance between lines 20a and 20b in the Fig. Since the transmission line 20 shown in Figure 4 is narrower than the second distances L2 mentioned above, coupling occurs between lines 20a and 20b. As a result, a high-frequency current applied to line 20b flows directly into line 20a through the point of coupling mentioned above, without flowing through the resistor 21 provided between lines 20a and 20b, as indicated by a broad arrow in Figure 4. Fig. 4 shown.

[0043] In this case, in the Fig. In the conventional high-frequency amplifier shown in Figure 4, a circulating current path (loop) is formed in which the high-frequency current applied to line 20b flows through the coupling point mentioned above into line 20a, passes through the amplifying element 1 and an input matching circuit and is applied again to line 20b of an output matching circuit (transmission line 20).

[0044] In the Fig. However, in the conventional high-frequency amplifiers shown in Figure 4, there is a possibility that the amplification of the high-frequency current in the circulating current path (loop) cannot be attenuated, and oscillation occurs. In particular, in line 20a, unlike in line 20b, there is no path in which the high-frequency current is attenuated. Therefore, in the circuit shown in Fig. The 4 conventional high-frequency amplifiers shown are more likely to exhibit an oscillation than the one shown in Fig. 2 high-frequency amplifiers shown according to embodiment 1.

[0045] A simple method for comparing the beneficial effects of the in Fig. 2 high-frequency amplifier shown according to embodiment 1 with that of the in Fig. The difference in the conventional high-frequency amplifier shown in Figure 4 is to compare the number of resistances present in the channels through which high-frequency currents flow. For example, in the amplifier shown in Figure 4, the resistance in Figure 4 is 1. Fig. In the high-frequency amplifier shown in embodiment 1, three resistors 4 are present in the flow channels through which high-frequency currents flow. Fig. In the conventional high-frequency amplifier shown in 4, only two resistors 21 are present in the flow channels. Since the high-frequency amplifier according to embodiment 1 in Fig. 2. It allows high-frequency currents to be attenuated with a larger number of resistors than the conventional high-frequency amplifier in Fig. 4, the effect of suppressing vibrations is also high.

[0046] Furthermore, in the Fig. In the transmission line 20 shown in section 5, a high-frequency current with opposite phase is applied only to line 20b from a gain element 1. In the case of the Fig. In the transmission line 20 shown in Figure 5, coupling occurs between lines 20a and 20b and between lines 20b and 20c because the distance between lines 20a and 20b and the distance between lines 20b and 20c is smaller than the second distances L2 mentioned above.

[0047] As a result, a high-frequency current applied to line 20a flows through the point of the aforementioned coupling directly into line 20b, without flowing through the resistor 21 provided between lines 20a and 20b, as indicated by a broad arrow in Fig. Figure 5 shows that a high-frequency current applied to line 20c flows directly into line 20b through the point of coupling mentioned above, without flowing into the resistor 21 provided between lines 20b and 20c.

[0048] In this case, in the Fig. In the 5 conventional high-frequency amplifiers shown, circulating current passages (loops) are formed in which the high-frequency current applied to line 20a and the high-frequency current applied to line 20c flow through the two coupling points mentioned above into line 20b and through the amplifying elements 1 and the input matching circuit and are applied again to lines 20a and 20c of the output matching circuit (transmission line 20).

[0049] In the Fig. However, in the conventional high-frequency amplifiers shown in Figure 5, there is a possibility that the amplification of the high-frequency currents cannot be attenuated in the circulating current paths (loops), leading to oscillations. In particular, lines 20a and 20b lack paths where the high-frequency currents are attenuated, unlike line 20c. Therefore, in the circuit shown in Figure 5, oscillations occur. Fig. The 5 conventional high-frequency amplifiers shown are more likely to exhibit parasitic oscillation or vibration than the one shown in Fig. 3 high-frequency amplifiers shown according to embodiment 1.

[0050] As a simple method for comparing the beneficial effects of the in Fig. 3 high-frequency amplifier according to embodiment 1 with that of the in Fig. In the conventional high-frequency amplifier shown in Figure 5, there is a method for comparing the number of resistors present in the channels through which high-frequency currents flow. For example, in the amplifier shown in Figure 5, the number of resistors in the amplifier is 1. Fig. In the high-frequency amplifier shown in embodiment 1, two resistors 4 are present in the flow channels through which high-frequency currents flow. Fig. In the conventional high-frequency amplifier shown in 5, only one resistor 21 is present in the flow channel. Since the high-frequency amplifier according to embodiment 1 in Fig. 3. It makes it possible to attenuate high-frequency currents with a larger number of resistors than the conventional high-frequency amplifier in Fig. 5, the effect of suppressing vibrations is also high.

[0051] The explanation above illustrates the example where the output terminal of each of the four amplifiers 1 and one end of each of the lines 3a, 3b, 3c, and 3d that form the transmission line 3 are connected via wire 2. However, this wire 2 is not strictly necessary and can be omitted. In this case, the output terminal of each of the four amplifiers 1 is directly connected to the end of each of the lines 3a, 3b, 3c, and 3d that form the transmission line 3, as shown, for example, in Fig. 6 shown. Fig. For simplicity, the reinforcing elements 1 are represented by rectangular frames.

[0052] Although the above explanation describes the example in which the high-frequency amplifier is designed to contain the four amplifying elements 1 and the transmission line 3, several units, each containing the four amplifying elements 1 and the transmission line 3, can also be provided in the high-frequency amplifier.

[0053] Although the explanation above uses the example of each of the conductors that make up transmission line 3 having a linear shape, not every conductor necessarily has to have a linear shape. For example, in transmission line 3, the effect of any electrical coupling between conductors at a point connected to resistor 4 is less than at any other point.

[0054] Accordingly, for example, the lines 3a and 3b, which form the second distance L2, can have a shape in which the lines project towards a corresponding resistor 4 such that they are close together at the points where the lines are connected to the resistor 4, and the lines 3c and 3d, which form the second distance L2, can have a shape in which the lines project towards a corresponding resistor 4 such that they are close together at the points where the lines are connected to the resistor 4, as in Fig. Figure 7 shows that in the case where the high-frequency amplifier is designed in this way, the coupling effect between the lines at their parts connected to the resistor 4 in the transmission line 3 is high compared to the case where each line has a linear shape, and high-frequency currents flow easily into the resistor 4. This improves the oscillation suppression effect in the high-frequency amplifier.

[0055] The explanation above also clarifies the example where the output matching circuit on the output terminal 6 side of the high-frequency amplifier is formed by transmission line 3. However, instead of or in addition to this configuration, the input matching circuit on the input side of the high-frequency amplifier can also be formed by transmission line 3. More precisely, in the high-frequency amplifier circuit, at least one of the input and output matching circuits must be formed solely by transmission line 3.

[0056] Although the above explanation uses the example of four amplifying elements 1 (m=4), in particular assuming that the number of amplifying elements 1 is an even number greater than or equal to four, because each of the lines forms one of the line pairs in the case where each of the line pairs is set up by combining two lines from one end of the transmission line in the order along the direction in which the lines are arranged side by side, the effect of suppressing vibrations is improved, as mentioned above.

[0057] However, in the high-frequency amplifier according to embodiment 1, a certain advantageous effect is achieved if the number of amplifying elements 1 is an integer greater than or equal to three.

[0058] In the high-frequency amplifier, for example, three amplification elements 1 can be provided (m=3), as in Fig. Figure 8 shows that in this case the comb structure 30, which includes the transmission line 3, has three parallel lines 3a, 3b and 3c.

[0059] In the Fig. In the high-frequency amplifier shown in the diagram 8, there are also two or more spacings between adjacent lines of the three lines 3a, 3b and 3c (in this example, two spacings), each comprising a first spacing L1 and a second spacing L2 that is larger than the first spacing L1. In the example of Fig. 8 is the distance between lines 3b and 3c, the first distance L1, and the distance between lines 3a and 3b is the second distance L2, which is greater than the first distance L1.

[0060] An advantageous effect of the high-frequency amplifier in this case is demonstrated by: Fig. 9 explained.

[0061] Fig. Figure 9 shows a case in which the amplifying element 1, which of the three amplifying elements 1 is connected to the outermost line 3a, operates with an opposite phase, while the amplifying elements 1, which are connected to the other lines 3b and 3c, operate with the same phase. In this case, a high-frequency current with the opposite phase (in the opposite direction) is applied in transmission line 3 only to line 3a from amplifying element 1.

[0062] Since a second distance L2 is formed between the lines in transmission line 3, which is sufficiently large to at least prevent electrical coupling between lines 3a and 3b, no coupling occurs between these lines in this case. Therefore, a high-frequency current applied to line 3b flows through the resistor 4, which is provided between lines 3a and 3b, into line 3a, as indicated by a broad arrow in Fig. 9 is shown, and is damped because it flows through this resistor 4. Therefore, in the high-frequency amplifier, the high-frequency current is damped and oscillations are suppressed.

[0063] Even if slight coupling occurs between lines 3a and 3b, the high-frequency current applied to line 3b flows through the resistor 4 between the lines into line 3a, instead of flowing into line 3a through the coupling point mentioned above, if the impedance of the resistor 4 between the lines is lower than the impedance between the lines at the point of this coupling. Therefore, in the high-frequency amplifier, the high-frequency current is attenuated and the oscillations are suppressed in this case as well.

[0064] Furthermore, a case is considered in which a circulating current path (loop) is formed in which part or all of the high-frequency current applied to line 3b does not flow through the resistor 4 provided between lines 3a and 3b, but through the coupling point mentioned above into line 3a and then through the amplifying element 1 and an input matching circuit and is applied again to line 3b of the output matching circuit (transmission line 3).

[0065] In this case, the amplified high-frequency current applied to line 3b flows through the resistor 4 between lines 3b and 3c into line 3c, as indicated by a broad arrow in Fig. Figure 9 illustrates this. The high-frequency current applied to line 3b flows through resistor 4 into the adjacent line (line 3c), as mentioned above, and is thereby attenuated. Therefore, in the high-frequency amplifier according to embodiment 1, even if a circulating current path (loop) is formed as described above, the increase in the high-frequency current can be prevented and oscillations suppressed.

[0066] The beneficial effect of the in Fig. The high-frequency amplifier shown in section 8 is explained here using the following: Fig. 10 explained in more detail. Fig. Figure 10 shows an example comparing the fluxes of high-frequency currents in a conventional high-frequency amplifier with those in Fig. 9.

[0067] In Fig. Reference numeral 10 denotes a transmission line contained in the conventional high-frequency amplifier. This transmission line 20 comprises: a comb structure 200 with three parallel lines 20a, 20b, and 20c and a connecting part 20f; and resistors 21, each provided between adjacent lines of the three lines, as in the Fig. 8 shown transmission line 3.

[0068] The ends of the three lines 20a, 20b, and 20c are connected one-to-one via wires 2 (not shown) to three amplifier elements (not shown). Furthermore, the other ends of the three lines 20a, 20b, and 20c are connected together to form the connecting section 3f. Reference numeral 26 also designates an output terminal of the conventional high-frequency amplifier.

[0069] In transmission line 20, all distances between the lines are essentially the same, unlike in transmission line 3 in embodiment 1. Furthermore, all distances between the lines are smaller than the second distance L2 mentioned above.

[0070] At the Fig. In the transmission line 20 shown in Figure 10, for example, only line 20a is supplied with a high-frequency current with the opposite phase by the amplifying element 1. Since the distance between lines 20a and 20b in the Fig. Since the distance L2 between the transmission line 20 shown in Figure 10 is smaller than the second distance L2 mentioned above, coupling occurs between lines 20a and 20b. As a result, a high-frequency current applied to line 20b flows directly into line 20a through the coupling point mentioned above, without flowing through the resistor 21 provided between lines 20a and 20b, as indicated by a broad arrow in Figure 10. Fig. 10 shown.

[0071] In this case, in the Fig. In the conventional high-frequency amplifier shown in Figure 10, a circulating current path (loop) is formed in which the high-frequency current applied to line 20b flows through the coupling point mentioned above into line 20a, passes through the amplifying element 1 and an input matching circuit and is applied again to line 20b of the output matching circuit (transmission line 20).

[0072] In the Fig. However, in the conventional high-frequency amplifiers shown in Figure 10, there is a possibility that the amplification of the high-frequency current in the circulating current path (loop) cannot be damped, and oscillation occurs. In particular, in line 20a, unlike in line 20b, there is no path in which the high-frequency current is damped. Therefore, in the circuit shown in Figure 10, oscillation occurs. Fig. The 10 conventional high-frequency amplifiers shown are more likely to produce an oscillation than the one shown in Fig. 8 high-frequency amplifiers shown.

[0073] A simple method for comparing the beneficial effect of the in Fig. 8 high-frequency amplifier shown with that of the one in Fig. The difference in the conventional high-frequency amplifier shown in 10 is to compare the number of resistances present in the flow path of a high-frequency current. For example, in the high-frequency amplifier according to embodiment 1 in Fig. 8 Two resistors 4 are present in the flow channel through which a high-frequency current flows, in the conventional high-frequency amplifier in Fig. 10 only one resistance 21 is present in the flow channel. Since the in Fig. The 8 high-frequency amplifiers shown make it possible to attenuate the high-frequency current with a larger number of resistors than in the Fig. The 10 conventional high-frequency amplifiers shown also have a high effect on suppressing vibrations.

[0074] As already mentioned, in the high-frequency amplifier according to embodiment 1, it is possible, in the case that the number of amplifying elements 1 is an integer greater than or equal to three, to realize both the suppression of oscillations and an impedance reduction in the matching circuits by including the first distance L1 and the second distance L2, which are greater than the first distance L1, in the multiple distances that are formed between adjacent lines.

[0075] The explanation above illustrates the example where the output terminal of each of the three amplifiers 1 and one end of each of the lines 3a, 3b, and 3c that make up the transmission line 3 are connected via wire 2. However, this wire 2 is not strictly necessary and can be omitted. In this case, the output terminal of each of the three amplifiers 1 is directly connected to the end of each of the lines 3a, 3b, and 3c that make up the transmission line 3, as shown, for example, in Fig. 11 shown. In Fig. For the sake of simplicity, the reinforcement elements 1 are represented by rectangular frames.

[0076] Although the above explanation describes the example in which the high-frequency amplifier is set up to contain the three amplification elements 1 and the transmission line 3, several units, each containing the three amplification elements 1 and the transmission line 3, can also be provided in the high-frequency amplifier.

[0077] Although the explanation above uses the example of each of the conductors that make up transmission line 3 having a linear shape, not every conductor necessarily has to have a linear shape. For example, in transmission line 3, the effect of any electrical coupling between conductors at a point connected to resistor 4 is less than at any other point.

[0078] Accordingly, for example, the conductors 3a and 3b, which form the second distance L2, can have a shape in which the conductors protrude towards a corresponding resistor 4 such that they are close together at the points where the conductors are connected to the resistor 4, as in Fig. Figure 12 shows that when the high-frequency amplifier is set up in this way, the coupling effect between the lines at their parts connected to the resistor 4 in the transmission line 3 is high compared to the case where each line has a linear shape and a high-frequency current flows easily into the resistor 4. Therefore, the oscillation suppression effect in the high-frequency amplifier is improved.

[0079] The above explanation also clarifies the example where the output matching circuit at output terminal 6 of the high-frequency amplifier is replaced by the one described in Fig. The transmission line 3 shown in section 8 is formed. However, instead of or in addition to this configuration, the input matching circuit on the input side of the high-frequency amplifier can also be provided by the configuration shown in section 8. Fig. The transmission line 3 shown in section 8 is formed. More precisely, in the high-frequency amplifier circuit, at least one of the input and output matching circuits must consist only of the one shown in Fig. The transmission line 3 shown in section 8 exists.

[0080] Although the above explanation refers to the case m=3 or m=4, i.e., the case where the number of reinforcing elements 1 is three or four, the number of reinforcing elements 1 can be an integer greater than or equal to three, e.g., five.

[0081] In this case, the high-frequency amplifier comprises an input matching circuit and an output matching circuit, as well as five gain elements 1. Furthermore, at least one of the input and output matching circuits comprises: a comb structure 30 with five conductors 3a, 3b, 3c, 3d, and 3e, one end of which is connected one-to-one to the five gain elements 1, and a connecting part 3f in which the other ends of the five conductors are connected to each other; and resistors 4, each provided between adjacent conductors of the five conductors, as shown in Fig. 13 shown.

[0082] Furthermore, in at least one of the input and output matching circuits, several (in this example, four) gaps are formed between adjacent lines of the five lines, including first gaps L1 and second gaps L2, which are larger than the first gaps L1. Even if the high-frequency amplifier is configured so that the number of gain elements 1 is five, as mentioned above, the high-frequency amplifier enables both the suppression of oscillations and an impedance reduction in the matching circuits, as in the case where the number of gain elements 1 is three or four.

[0083] As mentioned above, a high-frequency amplifier according to this embodiment 1 comprises an input matching circuit, an output matching circuit, and m (m is an integer greater than or equal to three) gain elements 1. At least one of the input and output matching circuits comprises: a comb structure 30 with m lines, one end of which is connected one-to-one to the m gain elements 1, and a connecting part 3f to which the other ends of the m lines are connected; and resistors 4, each provided between adjacent lines of the m lines, and several gaps, each formed between adjacent lines of the m lines, comprising a first gap L1 and a second gap L2, which is greater than the first gap L1. Therefore, the high-frequency amplifier according to embodiment 1 enables both the suppression of oscillations and impedance reduction in the matching circuits.

[0084] Furthermore, m is an even number greater than or equal to four, and in the comb structure 30, each of the conductor pairs is formed by combining two adjacent conductors from the m conductors from one end of the comb structure in a direction in which the m conductors are arranged side by side, and the distance between the conductor pairs is the first distance L1 and the distance between the conductors forming each of the conductor pairs is the second distance L2. Since in the high-frequency amplifier according to embodiment 1 each of the m conductors from which the comb structure 30 is formed forms one of the conductor pairs, the effect of suppressing vibrations is improved.

[0085] Furthermore, the second gap L2 is wide enough to at least prevent electrical coupling between the conductors forming the second gap L2. As a result, the vibration suppression effect is improved in the high-frequency amplifier according to embodiment 1.

[0086] According to this embodiment 1, a matching circuit further comprises: a comb structure 30 with m conductors, one end of which is connected one-to-one to m (m is an integer greater than or equal to three) amplifying elements 1, and a connecting part 3f to which the other ends of the m conductors are connected; and resistors 4, each provided between adjacent conductors of the m conductors, and several gaps, each formed between adjacent conductors of the m conductors, comprising a first gap L1 and a second gap L2, which is greater than the first gap L1. Consequently, the matching circuit according to embodiment 1 also enables the suppression of oscillations in a high-frequency amplifier containing the amplifying elements 1, while simultaneously achieving impedance reduction.

[0087] Furthermore, m in the matching circuit is an even number greater than or equal to four, and in the comb structure 30, each of the conductor pairs is formed by combining two adjacent conductors from the m conductors from one end of the comb structure in a direction in which the m conductors are arranged side by side, and the distance between the conductor pairs is the first distance L1 and the distance between the conductors that form each of the conductor pairs is the second distance L2. Since in the matching circuit according to embodiment 1 each of the m conductors from which the comb structure 30 is formed forms one of the conductor pairs, the effect of suppressing vibrations in the high-frequency amplifier with the amplifying elements 1 is improved. Example 2.

[0088] In embodiment 1, the high-frequency amplifiers are described that can implement both vibration suppression and impedance reduction in matching circuits. In embodiment 2, a high-frequency amplifier is described that can implement both vibration suppression and impedance reduction in matching circuits.

[0089] In embodiment 1, there is a case in which in the Fig. In the high-frequency amplifier shown in Figure 8, the amplifier element 1 connected to line 3b operates with an opposite phase to the other three amplifier elements 1, while the amplifier elements 1 connected to lines 3a and 3c operate with the same phase. An example of the flow of high-frequency currents in this case is shown in Figure 8. Fig. 14 shown.

[0090] As in Fig. As shown in Figure 14, in the above-mentioned case, no coupling occurs between the lines because the second distance L2 is formed in transmission line 3, which is sufficiently large to at least prevent electrical coupling between lines 3a and 3b. Therefore, a high-frequency current applied to line 3b flows through the resistor 4 provided between lines 3a and 3b into line 3a, as indicated by a broad arrow in Figure 14. Fig. 14 is shown, and is damped because it flows through this resistor 4. Therefore, in the high-frequency amplifier, the high-frequency current is damped and oscillations are suppressed.

[0091] Even if slight coupling occurs between lines 3a and 3b, the high-frequency current applied to line 3b flows through the resistor 4 between the lines into line 3a, instead of flowing into line 3a through the coupling point mentioned above, if the impedance of the resistor 4 between the lines is lower than the impedance between the lines at the point of this coupling. Therefore, the high-frequency current is attenuated in the high-frequency amplifier, and the oscillations are suppressed in this case as well.

[0092] However, if lines 3b and 3c are considered, the first distance L1 formed between these lines 3b and 3c is narrower than the second distance L2 formed between lines 3a and 3b. Therefore, electrical coupling can occur between lines 3b and 3c.

[0093] If coupling occurs between lines 3b and 3c, a high-frequency current applied to line 3c does not flow through the resistor 4 provided between lines 3b and 3c, but rather through the coupling point mentioned above into line 3b, as indicated by a broad arrow in Fig. Figure 14 illustrates this. In this case, a loop can form in the high-frequency amplifier, in which the high-frequency current applied to line 3c flows through the coupling point mentioned above into line 3b, through a gain element 1 and the input matching circuit, and is then applied again to line 3c of the output matching circuit (transmission line 3). In this case, it is possible that the high-frequency current in the loop between the input and output matching circuits in the high-frequency amplifier will increase, resulting in oscillation.

[0094] Therefore, the high-frequency amplifier according to embodiment 2 is configured as, for example, in Fig. 15 shown to enhance the effect of suppressing vibrations.

[0095] As in Fig. As shown in Figure 15, in the high-frequency amplifier according to embodiment 2, an output matching circuit is formed by a transmission line 3, while an input matching circuit is formed by a transmission line 3'.

[0096] The transmission line 3', which forms the input matching circuit, comprises: a comb structure 30' with three lines 3a', 3b' and 3c', one end of which is connected one-to-one to the input terminals of three amplifying elements 1, and a connecting part 3f to which the other ends of the three lines are connected; and resistors 4, which are provided between adjacent lines of the three lines. Reference numeral 7 designates an input terminal of the high-frequency amplifier according to embodiment 2.

[0097] The transmission line 3, which forms the output matching circuit, also comprises: a comb structure 30 with three lines 3a, 3b and 3c, one end of which is connected one-to-one to the input terminals of the three amplifying elements 1, and a connecting part 3f, at which the other ends of the three lines are connected to each other; and resistors 4, which are provided between adjacent lines of the three lines.

[0098] Furthermore, in the input-side transmission line 3' and the output-side transmission line 3, several gaps (in this case two gaps) are formed between adjacent lines of the three lines, and the formed multiple gaps comprise a first gap L1 and a second gap L2, which is larger than the first gap L1, as in Fig. 15 shown. Then the input-side transmission line 3' and the output-side transmission line 3 are arranged over the three amplifying elements 1 such that the first distance L1 and the second distance L2 are opposite each other.

[0099] In this case, even if a high-frequency current with opposite phase applied to line 3c in the output transmission line 3 does not flow through the resistor 4 provided between lines 3b and 3c, but rather through the point of coupling occurring between lines 3b and 3c into line 3b, as for example in Fig. As shown in Figure 14, this high-frequency current is amplified by the amplifying element 1, which is connected to the line 3b via a wire 2, and applied to the line 3b', which has the transmission line 3' on the input side.

[0100] Since, on the other hand, a second distance L2, which is sufficiently large to at least prevent electrical coupling between lines 3a' and 3b', is formed between the lines on the input side, no coupling occurs between these lines. Therefore, a high-frequency current applied to line 3b' flows through the resistor 4 provided between lines 3a' and 3b' into line 3a' and is attenuated because it flows through this resistor 4.

[0101] As already mentioned, in the high-frequency amplifier according to embodiment 2, the input-side transmission line 3' and the output-side transmission line 3 are arranged over the three amplifying elements 1 such that the first distance L1 and the second distance L2 are opposite each other. Therefore, in the high-frequency amplifier according to embodiment 2, a high-frequency current can be guided more reliably through a resistor 4 on the input or output side. Consequently, in the high-frequency amplifier according to embodiment 2, the rise of the high-frequency current in the circulating current path (loop) formed between the input and output matching circuits can be prevented, and oscillations can be suppressed.

[0102] As mentioned above, the high-frequency amplifier according to this embodiment 2 comprises the input matching circuit, the output matching circuit, and the m (m is an integer greater than or equal to three) amplifying elements. The input matching circuit comprises: the comb structure 30' with the m lines, one end of which is connected one-to-one to the input terminals of the m amplifying elements 1, and the connecting part 3f', where the other ends of the m lines are connected to each other; and the resistors 4, which are provided between adjacent lines from the m lines. The output matching circuit comprises: the comb structure 30 with the m lines, one end of which is connected one-to-one to the output terminals of the m amplifying elements 1, and the connecting part 3f, where the other ends of the m lines are connected to each other.and the resistors 4, which are each provided between adjacent lines of the m lines, and in each of the input and output matching circuits, the multiple gaps formed between adjacent lines of the m lines comprise the first gap L1 and the second gap L2, which is wider than the first gap L1, and the input and output matching circuits are arranged above the amplifying elements 1 such that the first gap L1 and the second gap L2 are opposite each other. As a result, the high-frequency amplifier according to embodiment 2 can implement both the suppression of oscillations and an impedance reduction in the matching circuits more reliably compared to the amplifier according to embodiment 1.

[0103] It is understood that any combination of the above-mentioned embodiments is possible, that various modifications can be made to each component according to any of the above-mentioned embodiments, or that any component can be omitted according to any of the above-mentioned embodiments. For example, the transmission line 3 described in embodiment 1 can be applied to embodiment 2 in the case of m=4, such that the input and output matching circuits are formed by transmission lines with four conductors each, and the input and output matching circuits are arranged over the amplifying elements 1 such that a first distance L1 and a second distance L2 are opposite each other. INDUSTRIAL APPLICABILITY

[0104] The present disclosure can effect both the suppression of vibrations and an impedance reduction in matching circuits and is suitable for use in high-frequency amplifiers. Reference symbol list

[0105] 1 Amplifying element, 2 Wire, 3 Transmission line, 3' Transmission line, 3a Line, 3a' Line, 3ab Line pair, 3b Line, 3b' Line, 3c Line, 3c' Line, 3cd Line pair, 3d Line, 3f Connecting part, 3f' Connecting part, 4 Resistor, 6 Output terminal of the high-frequency amplifier, 7 Input terminal of the high-frequency amplifier, 20 Transmission line, 20a Line, 20b Line, 20c Line, 20d Line, 21 Resistor, 30 Comb structure, 30' Comb structure, L1 first spacing and L2 second spacing. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2010-219654 A

[0003]

Claims

[1] High-frequency amplifier with an input matching circuit, an output matching circuit and m (m is an integer greater than or equal to three) amplifying elements, wherein at least one of the input and output matching circuits comprises: a comb structure with m lines, one end of which is connected one-to-one to the m reinforcement elements, and a connecting part at which the other ends of the m lines are connected to each other; and Resistors are provided between adjacent lines from the m lines, and wherein a plurality of distances each formed between adjacent lines of the m lines includes a first distance and a second distance greater than the first distance. [2] A high-frequency amplifier according to claim 1, wherein m is an even number greater than or equal to four, and in the comb structure, each of the line pairs is formed by combining two adjacent lines out of the m lines from one end of the comb structure in order along a direction in which the m lines are arranged side by side, and wherein a distance between the line pairs is the first distance, and a distance between the lines constituting each of the line pairs is the second distance. [3] High-frequency amplifier with an input matching circuit, an output matching circuit and m (m is an integer greater than or equal to three) amplification elements, wherein the input matching circuit comprises: a comb structure with m lines, one end of which is connected one-to-one to the input terminals of the m amplification elements, and a connecting part in which the other ends of the m lines are connected to each other; and Resistors provided between adjacent lines from the m lines, and the output matching circuit includes: a comb structure with m lines, one end of which is connected one-to-one to the output terminals of the m amplification elements, and a connecting part in which the other ends of the m lines are connected to each other; and Resistors are provided between adjacent lines from the m lines, and wherein in each of the input and output matching circuits, a plurality of spaces each formed between adjacent lines of the m lines includes a first space and a second space wider than the first space, and the input and output matching circuits are arranged above the amplifying elements so that the first space and the second space are opposite to each other. [4] A high frequency amplifier according to any one of claims 1 to 3, wherein the second distance is large enough to at least prevent electrical coupling between lines forming the second distance. [5] Matching circuit with: a comb structure with m lines, one end of which is connected one-to-one to m (m is an integer greater than or equal to three) reinforcing elements, and a connecting part in which the other ends of the m lines are connected to each other; and Resistors each provided between adjacent lines of the m lines, wherein a plurality of distances each formed between adjacent lines of the m lines include a first distance and a second distance greater than the first distance. [6] The matching circuit according to claim 5, wherein m is an even number greater than or equal to four, and in the comb structure, each of the line pairs is formed by combining two adjacent lines out of the m lines from one end of the comb structure in order along a direction in which the m lines are arranged side by side, and wherein a distance between the line pairs is the first distance, and a distance between the lines constituting each of the line pairs is the second distance.

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