JP5910963B2 - Coupler and semiconductor device - Google Patents

Description

  The present invention relates to a coupler and a semiconductor device, for example, a coupler and a semiconductor device that distribute signals or combine signals.

  Couplers such as a distributor or a coupler are used to distribute a signal such as a high-frequency signal into a plurality of signals or to combine a plurality of signals. As the coupler, for example, a Wilkinson coupler is known (for example, Patent Document 1). In a Wilkinson coupler, two transmission lines are divided from a distribution point or a coupling point. Two transmission lines are connected by a resistor at a distance of 1/4 of the signal wavelength from the distribution point or the coupling point. Thereby, the isolation characteristic from one port which inputs or outputs two signals to the other port can be improved.

JP 2001-267862 A

  However, when a Wilkinson coupler is used as the coupler, the mounting area is increased. Alternatively, the isolation characteristics deteriorate at frequencies other than the fundamental wave. An object of the present invention is to reduce the mounting area or improve the isolation characteristics at frequencies other than the fundamental wave.

  The present invention provides a distribution point for distributing signals or a connection point for combining signals, two transmission lines through which the distributed signal or the signal to be combined propagates, and a predetermined distance from the distribution point or the connection point. A resistor electrically connected between the two transmission lines, and each of the two transmission lines is connected to the resistor from the distribution point or the coupling point, respectively. The coupler is folded back in the direction opposite to the direction leading to the resistor. According to the present invention, the mounting area can be reduced.

  In the above configuration, the predetermined distance may be a quarter of the wavelength of the signal.

  In the above configuration, of the two transmission lines, the characteristic impedance between the distribution point or the coupling point and the resistance, and the wavelength of the signal 1 opposite to the distribution point or the coupling point from the resistance. The characteristic impedance between up to / 4 can be set equal.

  The present invention combines a distributor that distributes an input signal into a plurality, a plurality of transistors that use a nitride semiconductor to which the input signals that are distributed into the plurality are input, and a plurality of output signals of each of the plurality of transistors. A semiconductor device, wherein at least one of the distributor and the coupler includes the coupler.

  The present invention provides a distribution point for distributing a signal or a coupling point for combining signals, two transmission lines through which the distributed signal or the signal to be combined propagates, and the distribution in each of the two transmission lines. A first resistor whose both ends are electrically connected between the two transmission lines at a position where the distance from the point or the coupling point is 1/6 and 1/2 of the wavelength of the signal; It is a coupler characterized by comprising. According to the present invention, isolation characteristics can be improved at frequencies other than the fundamental wave.

  In the above configuration, the two transmission lines may be folded back in a direction opposite to the direction from the distribution point or the coupling point to the first resistor.

  In the above-described configuration, a configuration is provided in which a second resistor whose both ends are electrically connected between the two transmission lines at a position where the distance from the distribution point or the coupling point is 1/4 of the wavelength of the signal. It can be.

  The said structure WHEREIN: A said 1st resistance can be set as the structure which cross | intersects a part of said two transmission lines up and down.

  The present invention combines a distributor that distributes an input signal into a plurality, a plurality of transistors that use a nitride semiconductor to which the input signals that are distributed into the plurality are input, and a plurality of output signals of each of the plurality of transistors. A semiconductor device, wherein at least one of the distributor and the coupler includes the coupler.

  According to the present invention, the mounting area can be reduced, or the isolation characteristics can be improved at frequencies other than the fundamental wave.

1A is a plan view of a coupler according to Comparative Example 1, and FIG. 1B is a plan view of a coupler according to Comparative Example 2. FIG. 2A is a plan view of the coupler according to the first embodiment, and FIG. 2B is a cross-sectional view taken along line AA in FIG. FIG. 3 is a plan view of a coupler according to a modification of the first embodiment. FIG. 4 is a plan view of the semiconductor device according to the second embodiment. FIG. 5A to FIG. 5C are plan views of the coupler according to the third embodiment. FIG. 6A to FIG. 6D are circuit diagrams used for the simulation. FIG. 7 is a simulation result showing the isolation characteristics between the ports P2 and P3 with respect to the frequency. FIG. 8 is a plan view of the coupler according to the fourth embodiment. FIG. 9A is a plan view of the coupler according to the fifth embodiment, and FIG. 9B is a cross-sectional view taken along the line AA in FIG. 9A. FIG. 10A is a plan view of the coupler according to the sixth embodiment, and FIG. 10B is a cross-sectional view taken along line AA of FIG.

  First, a comparative example will be described. 1A is a plan view of a coupler according to Comparative Example 1, and FIG. 1B is a plan view of a coupler according to Comparative Example 2. As shown in FIG. 1A, a signal line made of a metal layer 13 is formed on the dielectric layer 20. A ground metal layer (not shown) is formed on the back surface of the dielectric layer 20. The transmission line 12 is formed by the signal line sandwiching the dielectric layer 20 and the ground metal layer. The transmission line 12 is a microstrip line.

  The coupler according to Comparative Example 1 distributes the signal input from the port P1 into two signals at the distribution point 10 and outputs the two signals to the ports P2 and P3. Alternatively, the two signals input from the ports 2 and P3 are combined at the connection point 10 and output to the port 1. In the following comparative examples and examples, a case where a signal input from the port P1 is mainly distributed to the ports P2 and P3 will be described as an example.

  In Comparative Example 1, by setting the characteristic impedance of the two transmission lines 12 to 100Ω, the impedance of the distribution point 10 viewed from the port P1 can be set to 50Ω. For example, the characteristic impedance of the transmission line 11 from the port P1 to the distribution point 10 is 50Ω. As a result, the input signal input from the port P1 is distributed at the distribution point 10, propagated through the two transmission lines 12, and then output from the ports P2 and P3. In this case, the output impedance is 100Ω.

  However, the coupler according to Comparative Example 1 has poor isolation characteristics between the ports P2 and P3. For example, a part of the signal input from the port P3 is output to the port P2. The Wilkinson coupler according to Comparative Example 2 solves such a problem.

  As shown in FIG. 1B, the coupler according to the comparative example 2 electrically connects the resistor 14 between the two transmission lines 12 at a distance L1 that is ¼ of the signal wavelength λ from the distribution point 10. Thereby, among the signals input from the port P3, the phase of the signal via the resistor 14 and the signal via the distribution point 10 can be inverted. Therefore, the signal input from the port P3 cancels out the signal via the resistor 14 and the signal via the distribution point 10, and is not output to the port P2. Thus, the isolation characteristic between the ports P2 and P3 can be improved. Further, the characteristic impedance of the transmission line 12a (λ / 4 line) between the distribution point 10 and the resistor 14 is set to 70.7Ω, for example. Thereby, the impedance can be converted from 100Ω to 50Ω by the λ / 4 line. The characteristic impedance of the transmission line 12d from the resistor 14 to the port P2 or P3 is, for example, 50Ω. Other configurations are the same as those of the first comparative example, and the description thereof is omitted.

  However, in Comparative Example 2, since the λ / 4 line (transmission line 12a) is provided, the mounting area becomes large.

  FIG. 2A is a plan view of the coupler according to the first embodiment, and FIG. 2B is a cross-sectional view taken along line AA in FIG. As shown in FIG. 2A, the two transmission lines 12 are folded back in directions opposite to the direction from the distribution point 10 to the resistor 14 in the region connected to the resistor 14. The transmission line 12 from the resistor 14 to the port P2 or P3 is the transmission line 12b. The transmission line 12b extends so that a signal propagates in a direction opposite to the transmission line 12a from the distribution point 10 to the resistor 14. The lengths of the two transmission lines 12b are L2.

  As shown in FIG. 2B, a metal layer 22 such as Cu or Au is formed on the entire bottom surface of the dielectric layer 20 such as aluminum oxide. A metal layer 13 such as Cu or Au is formed on the upper surface of the dielectric layer 20. The transmission line 12 is formed by the metal layers 13 and 22 sandwiching the dielectric layer 20. The metal layers 13 of the transmission line 12 are connected by a resistor 14. The resistor 14 is a thin film resistor such as TaN formed on the dielectric layer 20, for example.

  According to the first embodiment, in the coupler including the resistor 14 electrically connected between the two transmission lines 12 at a predetermined distance L1 from the distribution point or the coupling point 10, each of the two transmission lines 12 is connected to the resistor. In the region connected to 14, it is folded back in the direction opposite to the direction from the distribution point or coupling point 10 to the resistor 14. Thereby, compared with FIG.1 (b) of the comparative example 2, a coupler can be shortened and a mounting area can be reduced.

  Further, a predetermined distance L1 from the distribution point or coupling point 10 to the resistor 14 is set to 1/4 of the signal wavelength. Thereby, the isolation characteristic between the ports P2 and P3 can be improved.

  FIG. 3 is a plan view of a coupler according to a modification of the first embodiment. Transmission lines 12c are electrically connected between the two transmission lines 12b and the port P2 or P3, respectively. The transmission line 12c extends so that a signal propagates in the opposite direction to the transmission line 12b. For example, the transmission lines 12a and 12b have the same characteristic impedance (for example, 70.7Ω). The lengths of the transmission lines 12a and 12b are each ¼ of the wavelength λ in the signal. That is, the characteristic impedance between the distribution point 10 and the resistor 14 (transmission line 12a) is equal to that between the resistance 14 and the distribution point 10 to ¼ of the signal wavelength (transmission line b). To do. As a result, the combined length of the transmission lines 12a and 12b is λ / 2. Therefore, the impedance of the transmission line 12c viewed from the boundary between the transmission line 12b and the transmission line 12c and the impedance of the transmission line 12a viewed from the distribution point 10 can be made the same. For example, the characteristic impedance of the transmission line 12c may be 100Ω.

  By adopting the configuration of the modified example (FIG. 3) of the first embodiment, for example, a coupler having good isolation characteristics without changing the characteristic impedance of the transmission line 12 of the first comparative example (FIG. 1) (for example, 100Ω). Can be used.

  The second embodiment is an example of a semiconductor device using the coupler according to the first embodiment. FIG. 4 is a plan view of the coupler according to the second embodiment. The package includes a conductive substrate 52 and an insulating frame 50. Two insulating members 53 are provided on the conductive substrate 52 in the opposite sides of the insulating frame 50. An input terminal 54 and an output terminal 55 made of a metal film are formed on the two insulating members 53, respectively. The input terminal 54 and the output terminal 55 are electrically connected to leads outside the package.

  On the conductive substrate 52, the substrates 34, 36, 42 and 44 and the semiconductor chip 40 are mounted. The semiconductor chip 40 is a transistor (for example, a field effect transistor) using, for example, a nitride semiconductor. The nitride semiconductor is a semiconductor containing, for example, GaN, InN, AlN, InGAN, AlGaN, InAlN, or InAlGaN. A plurality of semiconductor chips 40 are mounted. Input matching circuits are formed on the substrates 34 and 42. For example, an output matching circuit is formed on the substrates 36 and 44. The substrates 42 and 44 are provided corresponding to the semiconductor chips 40, respectively. The input matching circuit is a circuit that matches the input impedance of the transistor. The output matching circuit is a circuit that matches the output impedance of the transistor.

  The substrate 34 is made of a dielectric layer, and a pattern 31 for distributing an input signal to each substrate 42 is formed. The pattern 31 and the input terminal 54 are electrically connected by a bonding wire 56. A signal input to the substrate 34 via the input terminal 54 is divided into two by the distributor 30. The distributor 30 is a coupler according to the first embodiment, for example. The signal is then further distributed into a number corresponding to the number of semiconductor chips 40. The substrate 36 is made of a dielectric layer, and a pattern 33 for combining a plurality of signals output from the substrate 44 is formed. The signals output from the substrate 44 are combined, and the combiner 32 combines the two signals. The pattern 33 and the output terminal 55 are electrically connected by a bonding wire 56. The signal combined by the coupler 32 is output to the outside through the output terminal 55. The substrate 34, the substrate 42, the semiconductor chip 40, the substrate 44 and the substrate 36 are electrically connected by bonding wires 48.

  As described above, according to the second embodiment, each of the distributor 30 that distributes the input signal to the plurality of transistors, the plurality of transistors using the nitride semiconductor to which the plurality of input signals are input, and the plurality of transistors, respectively. And a combiner 32 for combining the plurality of output signals. In a plurality of transistors using a nitride semiconductor, since the gain is large, if a loop passing through the transistor, the distributor 30 and the coupler 32 is formed, oscillation easily occurs. Therefore, at least one of the distributor 30 and the coupler 32 includes the coupler according to the first embodiment. This makes it difficult to form a loop passing through the transistor, the distributor 30 and the coupler 32. Therefore, the occurrence of oscillation can be suppressed.

  FIG. 5A to FIG. 5C are plan views of the coupler according to the third embodiment. As shown in FIG. 5A, compared to FIG. 1B of Comparative Example 2, two transmission lines 12 are connected by a resistor 16a in a region having a distance L3 that is 1/6 of the signal wavelength from the distribution point 10. Has been. As shown in FIG. 5B, two transmission lines 12 are connected by a resistor 16b in a region having a distance L4 that is ½ of the wavelength of the signal from the distribution point. As shown in FIG. 5 (c), two transmission lines 12 are connected by resistors 16a and 16b in the region of distance L3 and distance L4 which is 1/6 of the wavelength of the signal from distribution point 10, respectively. Yes. The other configuration is the same as that of FIG.

  According to the third embodiment, in each of the two transmission lines 12, the distance from the distribution point or the coupling point 10 is at least one-sixth and one-half of the wavelength of the signal between the two transmission lines 12. Both ends of the resistors 16a and 16b (first resistor) are electrically connected. Thereby, the isolation between the ports P2 and P3 at at least one of the 3/2 frequency and the 1/2 frequency of the signal can be improved. For example, in a transistor using a nitride semiconductor as in the second embodiment, since the gain is large, nonlinear components having frequencies of 3/2 and 1/2 of the fundamental frequency are generated. According to the third embodiment, the isolation characteristics for such nonlinearity can be improved.

  The resistor 14 (second resistor) that is electrically connected between the two transmission lines 12 at a distance L1 that is ¼ of the wavelength of the input signal from the distribution point 10 may not be provided. In order to improve the isolation characteristics between the ports P2 and P3 in the fundamental wave, it is preferable to provide the resistor 14. In the third embodiment, as in the first embodiment, the two transmission lines 12 may be folded back in a direction opposite to the direction from the distribution point or the coupling point 10 to the resistor 16a. Thereby, the mounting area of the coupler can be reduced.

  The isolation characteristics of Comparative Example 1, Comparative Example 2 and Example 3 were simulated. FIG. 6A to FIG. 6D are circuit diagrams used for the simulation. FIG. 6A is a circuit diagram corresponding to the first comparative example. The transmission line 12 is defined as a line Z0. FIG. 6B is a circuit diagram corresponding to the second comparative example. The transmission line 12a is the line Z1, the transmission line 12d is the line Z0, and the resistance value of the resistor 14 is R1. FIG. 6C is a circuit diagram corresponding to FIG. 5A of the third embodiment. A transmission line 12 between the distribution point 10 and the resistor 16a is a line Z2, a transmission line 12 between the resistor 16a and the resistor 14 is a line Z3, and a transmission line 12 from the resistor 14 to the port P2 or P3 is a line Z0. The resistance value of the resistor R16a is R2, and the resistance value of the resistor 14 is R3. FIG. 6D is a circuit diagram corresponding to FIG. 5C of the third embodiment. The transmission line 12 between the distribution point 10 and the resistor 16a is the line Z2, the transmission line 12 between the resistor 16a and the resistor 14 is the line Z3, the transmission line 12 between the resistor 14 and the resistor 16b is the line Z4, and the resistor R16b is The transmission line 12 up to the port P2 or P3 is defined as a line Z0. The resistance value of the resistor R16a is R4, the resistance value of the resistor 14 is R5, and the resistance value of the resistor 16b is R6.

Table 1 shows the characteristic impedance and electrical length at 4 GHz of each line used in the simulation, and the resistance value of each resistor. Each resistance value is a value adjusted so that the isolation characteristic is improved.

  FIG. 7 is a simulation result showing the isolation characteristics between the ports P2 and P3 with respect to the frequency. In FIG. 7, Comparative Example 1 is indicated by a dotted line, Comparative Example 2 is indicated by a one-dot chain line, FIG. 5A of Example 3 is indicated by a solid line, and FIG. 5C of Example 3 is indicated by a broken line. As shown in FIG. 7, in Comparative Example 1, the isolation characteristics are poor. In Comparative Example 2, the isolation characteristics are good at 4 GHz, which is the fundamental frequency f0, but the isolation characteristics are poor at other frequencies (for example, f0 / 2, 3f0 / 2). In FIG. 5A of the third embodiment, the isolation characteristic near the frequency of 3f0 / 2 can be improved. In FIG. 5C of the third embodiment, the isolation characteristics near the frequencies f0 / 2 and 3f0 / 2 can be improved.

  FIG. 8 is a plan view of the coupler according to the fourth embodiment. As shown in FIG. 8, a resistor 16a is provided as compared with FIG. 4 of the modification of the first embodiment. Other configurations are the same as those of the first embodiment, and the description thereof is omitted.

  In the fourth embodiment, as in the first embodiment, the two transmission lines 12 may be folded back in a direction opposite to the direction from the distribution point or the coupling point 10 to the resistor 16a. Further, the two transmission lines 12 may be extended in the direction from the distribution point or coupling point 10 to the resistor 16a, respectively, as in the modification of the first embodiment. Thereby, the mounting area of the coupler can be reduced.

  FIG. 9A is a plan view of the coupler according to the fifth embodiment, and FIG. 9B is a cross-sectional view taken along the line AA in FIG. 9A. As shown in FIG. 9A, resistors 16a and 16b are provided as compared with FIG. 3 of the modified example of the first embodiment. As shown in FIG. 9B, the resistor 16 b and the transmission line 12 intersect with each other through the insulating layer 24. By intersecting, the mounting area of the coupler can be reduced. As the insulating layer 24, for example, polyimide or silicon oxide can be used. Further, the insulating layer 24 is not provided, and the resistor 16b and the transmission line 12 may cross each other through a space. Other configurations are the same as those in FIG.

  As in the fifth embodiment, at least one of the resistors 16a, 16b, and 14 may intersect with a part of the two transmission lines 12 in the vertical direction. Thereby, even when the transmission line 12 is folded, a resistor can be connected between the two transmission lines 12.

  FIG. 10A is a plan view of the coupler according to the sixth embodiment, and FIG. 10B is a cross-sectional view taken along line AA of FIG. As shown in FIG. 10A, the transmission line 11 is provided between the port P <b> 1 and the distribution point 10. The transmission line 12 is provided on both sides of the transmission line 11 so that the signal propagates in the direction opposite to the propagation direction of the signal on the transmission line 11. As shown in FIG. 10B, the resistors 16 a and 14 that connect the two transmission lines 12 and the transmission line 11 intersect with each other via the insulating layer 24. As the insulating layer 24, for example, polyimide or silicon oxide can be used. Further, the insulating layer 24 is not provided, and the resistor 16b and the transmission line 12 may cross each other through a space.

  As in the sixth embodiment, at least one of the resistors 16 a, 16 b and 14 may intersect with a part of the transmission line 11. Thereby, even when the transmission line 12 is provided on both sides of the transmission line 11, a resistor can be connected between the two transmission lines 12.

  The couplers of the third to sixth embodiments can be applied to at least one of the distributor 30 and the coupler 32 of the semiconductor device of the second embodiment.

  In the first to sixth embodiments, the signal distributed or combined by the coupler can be a high-frequency signal, for example. For a distance of 1/4, 1/6, or 1/2 of the wavelength of the signal, the frequency of the signal distributed or combined by the coupler can be used as a reference frequency. In addition, the characteristic impedance of each transmission line can be based on the frequency of a signal distributed or coupled by a coupler as a reference frequency. Further, the reference frequency can be any frequency within the band of a device in which the couplers according to the first and third to sixth embodiments are used, for example, an amplifying device. Furthermore, the reference frequency may be a frequency near the center of the band of the device.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. It can be changed.

DESCRIPTION OF SYMBOLS 10 Distribution point or coupling point 11 Transmission line 12 Transmission line 13 Metal layer 14 Resistance 16a, 16b Resistance 20 Dielectric layer 40 Semiconductor chip

Claims (9)

A distribution point for distributing signals or a coupling point for combining signals;
Two transmission lines through which the distributed signal or the combined signal respectively propagates;
A first resistor electrically connected between the two transmission lines at a first predetermined distance from the distribution point or the coupling point;
A second resistor electrically connected between the two transmission lines at a second predetermined distance longer than a first predetermined distance from the distribution point or the coupling point;
Comprising
Each of the two transmission lines, and two first transmission line between the distribution point or coupling point between the first resistor and connected to the region, in the region connected to the first resistor, each of the Two second transmission lines folded in a direction opposite to the direction from the distribution point or the coupling point to the first resistance so as to be provided outside the two first transmission lines;
The second resistor connects the two transmission lines by vertically intersecting the two first transmission lines . The coupler according to claim 1, wherein the first predetermined distance or the second predetermined distance is ¼ of the wavelength of the signal. A first transmission line for transmitting a signal input / output from the port;
  A distribution point for distributing a signal transmitted through the first transmission line, or a coupling point for combining signals and outputting them to the first transmission line;
  Two second transmission lines through which the distributed signal or the combined signal respectively propagates;
  A resistor electrically connected between the two second transmission lines at a predetermined distance from the distribution point or the coupling point;
  Comprising
  Each of the two second transmission lines is folded in a direction opposite to the direction from the port to the distribution point or coupling point so that the first transmission line is provided on both sides of the first transmission line. ,
  The resistor connects the two second transmission lines by vertically intersecting the first transmission line. The coupler according to claim 3 , wherein the predetermined distance is ¼ of the wavelength of the signal . A distribution point for distributing signals or a coupling point for combining signals;
Two transmission lines through which the distributed signal or the combined signal respectively propagates;
In each of the two transmission lines, a first resistor whose distance from the distribution point or the coupling point is 1/6 of the wavelength of the signal and whose both ends are electrically connected between the two transmission lines. When,
A coupler comprising: The two transmission lines are respectively connected to the distribution point or the coupling point such that a second portion other than the first portion from the distribution point or the coupling point to the first resistor is provided outside the first portion. The coupler according to claim 5, wherein the coupler is folded back in a direction opposite to the direction reaching the first resistor. A second resistor in which both ends are electrically connected between the two transmission lines at a position where the distance from the distribution point or the coupling point is 1/4 or 1/2 of the wavelength of the signal. The coupler according to claim 5 or 6, further comprising: A distribution point for distributing signals or a coupling point for combining signals;
Two transmission lines through which the distributed signal or the combined signal respectively propagates;
In each of the two transmission lines, the distance from the distribution point or the coupling point is at least one of 1/6 and 1/2 of the wavelength of the signal, and both ends are electrically connected between the two transmission lines. A first resistor connected to
Comprising
The coupler , wherein the first resistor intersects a part of the two transmission lines in the vertical direction. A distributor for distributing the input signal to a plurality of parts;
A plurality of transistors using nitride semiconductors, each of which receives a plurality of distributed input signals;
A coupler for combining a plurality of output signals of each of the plurality of transistors;
Comprising
9. A semiconductor device, wherein at least one of the distributor and the coupler includes the coupler according to claim 1 .

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