Circuit arrangement and doherty amplifier

Abstract

To provide a circuit device for impedance matching that can be miniaturized even when a transmission line is long.SOLUTION: A circuit device is for impedance matching with a transistor. The circuit device includes a substrate having a main surface, and a matching circuit provided on the main surface and connected to an input terminal or an output terminal of the transistor to perform impedance matching with the transistor. The matching circuit has bonding wires that are completed on the main surface and serve as internal wiring of the matching circuit.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to a circuit device and a Doherty amplifier.

Background Art

[0002] Patent Document 1 discloses a Doherty amplifier including a main amplifier and a peak amplifier. The main amplifier and the peak amplifier have a matching circuit.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A circuit device for impedance matching connected to an input terminal or an output terminal of a transistor is known. This circuit device is formed by forming circuit elements such as a filter and a delay line on a substrate. And this circuit device includes transmission lines inside and between each circuit element.

[0005] In such a circuit device, the length of the transmission line is set in consideration of impedance matching. Depending on the impedance of the transistor, the transmission line becomes long. In that case, a large area is required to lay the transmission line on the substrate, which is a factor in increasing the size of the circuit device.

[0006] An object of the present disclosure is to provide a circuit device for impedance matching that can be miniaturized even when the transmission line becomes long, and a Doherty amplifier including the circuit device.

Means for Solving the Problems

[0007] The circuit device according to the present disclosure is a circuit device for impedance matching with a transistor, and includes a substrate having a main surface, and a matching circuit provided on the main surface and connected to an input terminal or an output terminal of the transistor to perform impedance matching with the transistor. The matching circuit has bonding wires as internal wirings of the matching circuit that are completed on the main surface.

Advantages of the Invention

[0008] According to the present disclosure, it is possible to provide a circuit device for impedance matching that can be miniaturized even when the transmission line becomes long, and a Doherty amplifier including the circuit device.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

[0010] [Description of Embodiments of the Present Disclosure] First, the contents of the embodiments of the present disclosure will be listed and described. [1] A circuit device according to one aspect of the present disclosure is a circuit device for impedance matching with a transistor, and includes a substrate having a main surface, and a matching circuit provided on the main surface and connected to an input terminal or an output terminal of the transistor to perform impedance matching with the transistor. The matching circuit has a bonding wire as internal wiring of the matching circuit that is completed on the main surface.

[0011] Compared with a transmission line, the bonding wire can be arranged in proximity to other elements (other parts of the transmission line and capacitors, etc.) constituting the matching circuit in a plan view, or can straddle the other elements. Therefore, even when the transmission line becomes long, by replacing a part of the transmission line with a bonding wire, the area for laying the transmission line can be reduced. Accordingly, according to this circuit device, even when the transmission line becomes long, miniaturization of the circuit device is possible.

[0012] [2] In the circuit device of [1] above, the bonding wire may straddle other elements included in the matching circuit. In that case, since the space on the other elements is utilized, the area for laying the transmission line can be made smaller, and the circuit device can be miniaturized even further.

[0013] [3] In the circuit device of [1] or [2] above, the matching circuit has a filter, and the bonding wire may form part of the filter. In that case, since the area on the main surface required for the filter can be reduced, the circuit device can be miniaturized.

[0014] [4] In the circuit device of [3] above, the filter is a low-pass filter, and the first end of the bonding wire may be connected to the input end of the low-pass filter, and the second end of the bonding wire may be connected to the output end of the low-pass filter.

[0015] [5] In the circuit device of [3] above, the filter is a high-pass filter, and the bonding wire may form part of the bias wiring provided in the high-pass filter.

[0016] [6] In any one of the circuit devices of [1] to [5] above, the matching circuit has a delay line, and the bonding wire may form part of the delay line. In that case, since the area on the main surface required for the delay line can be reduced, the circuit device can be miniaturized.

[0017] [7] In any one of the circuit devices of [1] to [6] above, the matching circuit has a transmission line, and the bonding wire may be connected in series with the transmission line. In this way, by connecting the bonding wire in series with the transmission line, another transmission line connected to the transmission line, that is, part of the transmission line, can be replaced with the bonding wire. Therefore, the area for laying the transmission line can be reduced.

[0018] [8] The Doherty amplifier according to one aspect of the present disclosure is a Doherty amplifier including a main amplifier and a peak amplifier. The main amplifier has a first circuit device which is any one of the circuit devices from [1] to [7]. The peak amplifier has a second circuit device which is any one of the circuit devices from [1] to [7]. The first circuit device is arranged side by side with the second circuit device in a first direction. The extending direction of the bonding wire of the first circuit device as viewed from the normal direction of the main surface intersects with the extending direction of the bonding wire of the second circuit device as viewed from the same direction. In that case, crosstalk between the first circuit device and the second circuit device can be reduced.

[0019] [9] In the Doherty amplifier of [8] above, one of the bonding wires of the bonding wire of the first circuit device and the bonding wire of the second circuit device may be along the first direction. The other bonding wire of the bonding wire of the first circuit device and the bonding wire of the second circuit device may be along a second direction intersecting the first direction. One bonding wire may include a first portion closer to the other bonding wire and a second portion farther from the other bonding wire than the first portion. The inclination angle of the second portion with respect to the main surface may be larger than the inclination angle of the first portion with respect to the main surface. In that case, crosstalk between the first circuit device and the second circuit device can be further reduced.

[0020] [Details of Embodiments of the Present Disclosure] Specific examples of the circuit device and the Doherty amplifier of the present disclosure will be described below with reference to the drawings. It should be noted that the present invention is not limited to these examples, and is indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims. In the following description, the same elements in the description of the drawings are denoted by the same reference numerals, and redundant descriptions are omitted.

[0021] FIG. 1 is a perspective view showing a Doherty amplifier 1 according to an embodiment of the present disclosure. The Doherty amplifier 1 of this embodiment includes a base 10 having a main surface 11, a reference potential pattern 15 which is a metal film provided on the main surface 11 of the base 10, and a main amplifier 2A and a peak amplifier 2B provided on the reference potential pattern 15. In addition, the Doherty amplifier 1 includes pads 131 to 138 and wirings 121 to 128. The pads 131 to 138 are provided around the reference potential pattern 15. Each of the wirings 121 to 128 is a metal film provided on the main surface 11 of the base 10, and extends outward from the Doherty amplifier 1 from the region between each of the pads 131 to 138 and the main surface 11 of the base 10. Each of the wirings 121 to 128 is electrically connected to each of the pads 131 to 138. On the main surface 11 of the base 10, the main amplifier 2A, the peak amplifier 2B, the reference potential pattern 15, and the pads 131 to 138 are covered and protected by a resin body 14.

[0022] FIG. 2 is a perspective view showing the main part of the Doherty amplifier 1. FIG. 3 is a plan view showing the main part of the Doherty amplifier 1. As shown in FIGS. 1 to 3, the main amplifier 2A and the peak amplifier 2B are arranged side by side along the direction D1 (first direction). Each of the main amplifier 2A and the peak amplifier 2B has an integrated passive device (IPD) 3, a transistor 4, an integrated passive device (IPD) 5, and a transistor 6. The integrated passive device 3, the transistor 4, the integrated passive device 5, and the transistor 6 are arranged side by side in this order along the direction D2 (second direction) intersecting the direction D1. In the example shown in FIG. 1, each element (integrated passive device 3, transistor 4, integrated passive device 5, and transistor 6) of the main amplifier 2A and each element (integrated passive device 3, transistor 4, integrated passive device 5, and transistor 6) of the peak amplifier 2B are arranged apart from each other. On the other hand, in the examples shown in FIGS. 2 and 3, each element of the main amplifier 2A and each element of the peak amplifier 2B are arranged close to each other (or on the same substrate). The arrangement relationship between each element of the main amplifier 2A and each element of the peak amplifier 2B may be any of these.

[0023] The integrated passive device 3 is a circuit for matching the input impedance of the transistor 4. The integrated passive device 3 of the main amplifier 2A is electrically connected to the pad 131 via the bonding wire 161. The integrated passive device 3 of the main amplifier 2A receives the first signal from the wiring 121. The integrated passive device 3 of the peak amplifier 2B is electrically connected to the pad 132 via the bonding wire 162. The integrated passive device 3 of the peak amplifier 2B receives the second signal from the wiring 122. The second signal and the first signal are signals obtained by splitting from a single signal and having a phase difference given to each other.

[0024] Transistor 4 is the first-stage amplification section. The control terminal (gate) of transistor 4 is electrically connected to circuit device 3 via bonding wire 25. The transistor 4 of main amplifier 2A receives the first signal from circuit device 3 of main amplifier 2A and amplifies the first signal. The transistor 4 of peak amplifier 2B receives the second signal from circuit device 3 of peak amplifier 2B and amplifies the second signal.

[0025] Circuit device 5 is a circuit for matching the input impedance of transistor 6. Circuit device 5 of main amplifier 2A is electrically connected to the current terminal (drain) of transistor 4 of main amplifier 2A via bonding wire 26. Circuit device 5 of main amplifier 2A receives the amplified first signal from transistor 4 of main amplifier 2A. Circuit device 5 of peak amplifier 2B is electrically connected to the current terminal (drain) of transistor 4 of peak amplifier 2B via bonding wire 26. Circuit device 5 of peak amplifier 2B receives the amplified second signal from transistor 4 of peak amplifier 2B.

[0026] Transistor 6 is the second-stage amplification section. The control terminal (gate) of transistor 6 is electrically connected to circuit device 5 via bonding wire 27. The transistor 6 of main amplifier 2A receives the amplified first signal from circuit device 5 of main amplifier 2A and further amplifies the amplified first signal. The current terminal (drain) of transistor 6 of main amplifier 2A is electrically connected to pad 133 via bonding wire 163. The first signal amplified by transistor 6 of main amplifier 2A is output from wiring 123 to the outside of Doherty amplifier 1. The transistor 6 of peak amplifier 2B receives the amplified second signal from circuit device 5 of peak amplifier 2B and further amplifies the amplified second signal. The current terminal (drain) of transistor 6 of peak amplifier 2B is electrically connected to pad 134 via bonding wire 164. The second signal amplified by transistor 6 of peak amplifier 2B is output from wiring 124 to the outside of Doherty amplifier 1. The first signal and the second signal output from Doherty amplifier 1 are combined with each other outside Doherty amplifier 1.

[0027] The circuit device 5 of main amplifier 2A is connected to pad 135 via bonding wire 165. A first bias voltage is input to circuit device 5 from wiring 125. The circuit device 5 of main amplifier 2A is connected to pad 136 via bonding wire 166. A second bias voltage is input to circuit device 5 from wiring 126.

[0028] The circuit device 5 of peak amplifier 2B is connected to pad 137 via bonding wire 167. A first bias voltage is input to circuit device 5 from wiring 127. The circuit device 5 of peak amplifier 2B is connected to pad 138 via bonding wire 168. A second bias voltage is input to circuit device 5 from wiring 128.

[0029] FIG. 4 is a circuit diagram of the main amplifier 2A. The circuit devices 3 and 5 of the peak amplifier 2B have the same configuration as the main amplifier 2A, except for the resistance value of the resistor and the capacitance value of the capacitor. However, each of the circuit devices 3 and 5 of the peak amplifier 2B has a structure that is line-symmetric with respect to each of the circuit devices 3 and 5 of the main amplifier 2A. As shown in FIG. 4, the circuit device 3 includes a low-pass filter 3a and a delay line 3b.

[0030] The low-pass filter 3a is a so-called π-type low-pass filter and includes a capacitor 31, a transmission line 32, a capacitor 33, a resistor 34, and bonding wires 36 and 37. The bonding wire 36, the transmission line 32, and the bonding wire 37 constitute a signal transmission line for transmitting the first signal (the second signal in the case of the peak amplifier 2B), and are connected in series in this order between the bonding wire 161 (the bonding wire 162 in the case of the peak amplifier 2B) and the delay line 3b. That is, the bonding wire 36 is interposed between the input end of the low-pass filter 3a and the transmission line 32, and the bonding wire 37 is interposed between the transmission line 32 and the output end of the low-pass filter 3a. The capacitors 31 and 33 act as bypass capacitors with respect to the first signal (the second signal in the case of the peak amplifier 2B). The first electrode of the capacitor 31 is connected to the node between the bonding wire 161 (the bonding wire 162 in the case of the peak amplifier 2B) and the bonding wire 36 (i.e., the input end of the low-pass filter 3a). The second electrode of the capacitor 31 is connected to the reference potential pattern 15. The first electrode of the capacitor 33 is connected to the node between the bonding wire 37 and the delay line 3b (i.e., the output end of the low-pass filter 3a) via the resistor 34. The second electrode of the capacitor 33 is connected to the reference potential pattern 15.

[0031] Thus, bonding wires 36 and 37 form part of the low-pass filter 3a. In other words, the first ends of the bonding wires 36 and 37 are connected to the input end of the low-pass filter 3a, and the second ends of the bonding wires 36 and 37 are connected to the output end of the low-pass filter 3a. The bonding wires 36 and 37 are self-contained on the main surface 30a and do not extend to areas outside the area on the main surface 30a..

[0032] The delay line 3b includes a transmission line 35 and a bonding wire 38. The transmission line 35 and the bonding wire 38 form a signal transmission line and are connected in series with each other between the output end of the low-pass filter 3a and the bonding wire 25. The bonding wire 38 is interposed between the output end of the low-pass filter 3a and the transmission line 35. Thus, the bonding wire 38 forms part of the delay line 3b. The bonding wire 38 is self-contained on the main surface 30a and does not extend to areas outside the area on the main surface 30a..

[0033] As shown in FIG. 4, the circuit device 5 includes a low-pass filter 51, a high-pass filter 52, a delay line 53, a bias circuit 54, and harmonic processing circuits 55 and 56.

[0034] The low-pass filter 51 is a so-called L-type low-pass filter, and includes a capacitor 511, a transmission line 512, and a bonding wire 513. The transmission line 512 and the bonding wire 513 constitute a signal transmission line, and are connected in series with each other between the bonding wire 26 and the high-pass filter 52. That is, the bonding wire 513 is interposed between the transmission line 512 and the output terminal of the low-pass filter 51. The bonding wire 513 is completed on the main surface 50a and does not extend from the area on the main surface 50a to the outside area.. The capacitor 511 acts as a bypass capacitor. The first electrode of the capacitor 511 is connected to a node between the bonding wire 26 and the transmission line 512 (that is, the input terminal of the low-pass filter 51). The second electrode of the capacitor 511 is connected to the reference potential pattern 15.

[0035] The high-pass filter 52 includes a bonding wire 521, a transmission line 522, and capacitors 523, 524, 525. The capacitors 524, 525 are provided on the signal transmission line and act as coupling capacitors. The capacitors 524, 525 are connected in series with each other between the low-pass filter 51 and the delay line 53. The bonding wire 521, the transmission line 522, and the capacitor 523 are connected in series in this order between a node between the low-pass filter 51 and the capacitor 524 (that is, the input terminal of the high-pass filter 52) and the reference potential pattern 15. That is, the bonding wire 521 is interposed between the input terminal of the high-pass filter 52 and the transmission line 522. The bonding wire 521 is completed on the main surface 50a and does not extend from the area on the main surface 50a to the outside area.. A first bias voltage is input to the node between the transmission line 522 and the capacitor 523 via the bonding wire 165 from the pad 135 (via the bonding wire 167 from the pad 137 in the case of the peak amplifier 2B) with reference to FIGS. 2 and 3. Thus, the bonding wire 521 constitutes a part of the bias wiring provided in the high-pass filter 52. The capacitor 523 acts as a bypass capacitor for the first bias voltage.

[0036] The delay line 53 includes a bonding wire 532 and transmission lines 531 and 533. The transmission line 531, the bonding wire 532, and the transmission line 533 form a signal transmission line and are connected in series in this order between the output terminal of the high-pass filter 52 and the bonding wire 27. That is, the bonding wire 532 is interposed between the transmission line 531 and the transmission line 533. The bonding wire 532 is completed on the main surface 50a and does not extend from the region on the main surface 50a to the outer region..

[0037] The bias circuit 54 includes a resistor 541 and a capacitor 542. The first end of the resistor 541 is connected to the node between the transmission line 531 and the bonding wire 532. The second end of the resistor 541 is connected to the pad 136 via the bonding wire 166 (see FIGS. 2 and 3) and receives the second bias voltage from the pad 136 (in the case of the peak amplifier 2B, receives the second bias voltage from the pad 138 via the bonding wire 168). The capacitor 542 acts as a bypass capacitor with respect to the second bias voltage. The first electrode of the capacitor 542 is connected to the node between the transmission line 531 and the bonding wire 532. The second electrode of the capacitor 542 is connected to the reference potential pattern 15.

[0038] The harmonic processing circuit 55 includes a capacitor 551. The harmonic processing circuit 56 includes a capacitor 561. The first electrodes of the capacitors 551 and 552 are connected to the node between the bonding wire 27 and the control terminal (gate) of the transistor 24 via the bonding wires 28 and 29, respectively. The second electrodes of the capacitors 551 and 552 are connected to the reference potential pattern 15. The harmonic processing circuits 55 and 56 remove harmonic components from the first signal (the second signal in the case of the peak amplifier 2B) input to the transistor 24.

[0039] FIG. 5 is a plan view of the circuit device 3. FIG. 6 is a perspective view of the circuit device 3. As shown in FIGS. 5 and 6, the circuit device 3 includes a substrate 30 having a main surface 30a. Each element of the low-pass filter 3a and the delay line 3b described above is arranged on the main surface 30a. In addition, pads 301, 302, 304 to 311 are provided on the main surface 30a. Pads 301, 304, 307, 308, and 310 are arranged side by side along the direction D2 in a region near one end of the main surface 30a in the direction D1. Pads 302, 305, 306, and 309 are arranged side by side along the direction D2 in a region near the other end of the main surface 30a in the direction D1.

[0040] One end of a bonding wire 161 (bonding wire 162 in the case of the peak amplifier 2B) is fixed to the pad 301. The first electrode of the capacitor 31 is connected to the pad 301 via a wiring provided on the main surface 30a, and the second electrode of the capacitor 31 is connected to the pad 302. The pad 302 is connected to a reference potential pattern 15 (not shown) via a via 303 penetrating the substrate 30 in the thickness direction. The pad 304 is connected to a node between the pad 301 and the capacitor 31 via a wiring provided on the main surface 30a.

[0041] The pad 305 and the pad 306 are connected to each other via a transmission line 32 provided on the main surface 30a. The first end of a bonding wire 36 is fixed to the pad 304, and the second end of the bonding wire 36 is fixed to the pad 305. The first end of a bonding wire 37 is fixed to the pad 306, and the second end of the bonding wire 37 is fixed to the pad 307. The bonding wires 36 and 37 extend along the direction D1 in a plan view and straddle the transmission line 32. The bonding wire 37 is arranged side by side with the bonding wire 36 in the direction D2.

[0042] Pad 308 is connected to pad 307 via wiring provided on the main surface 30a. The first electrode of capacitor 33 is connected to the node between pad 307 and pad 308. The second electrode of capacitor 33 is connected to pad 311. Pad 311 is connected to a reference potential pattern 15 (not shown) via a via 312 that penetrates the substrate 30 in the thickness direction. The first end of bonding wire 38 is fixed to pad 308, and the second end of bonding wire 38 is fixed to pad 309. Bonding wire 38 extends along direction D1 in a plan view and straddles pad 311. Pad 309 is connected to pad 310 via a transmission line 35 provided on the main surface 30a. One end of bonding wire 25 is fixed to pad 310.

[0043] FIG. 7 is a plan view of the circuit device 5. As shown in FIG. 7, the circuit device 5 includes a substrate 50 having a main surface 50a. Each element of the low-pass filter 51, high-pass filter 52, delay line 53, bias circuit 54, and harmonic processing circuits 55, 56 described above is arranged on the main surface 50a. In addition, pads 571 to 573, 575 to 584, 586, and 587 are provided on the main surface 30a. Pads 571, 575, 576, 580, and 587 are arranged side by side along direction D2 in a region near one end of the main surface 30a in direction D1. Pads 578, 579, 581, and 584 are arranged side by side along direction D2 in a region near the other end of the main surface 30a in direction D1.

[0044] One end of a bonding wire 26 (see FIGS. 2 to 4) is fixed to a pad 571. A first electrode of a capacitor 511 is connected to the pad 571 via a wiring provided on a main surface 30a, and a second electrode of the capacitor 511 is connected to a pad 573. The pad 573 is connected to a reference potential pattern 15 (not shown) via a via 574 penetrating the substrate 50 in the thickness direction. A pad 572 is connected to a node between the pad 571 and the capacitor 511 via a wiring provided on the main surface 30a. A first end of a bonding wire 513 is fixed to the pad 572, and a second end of the bonding wire 513 is fixed to a pad 575. The bonding wire 513 extends along a direction D1 in a plan view and straddles the pad 573.

[0045] The pad 575 is connected to a pad 576 via a wiring on the main surface 50a. A first end of a bonding wire 521 is fixed to the pad 576, and a second end of the bonding wire 521 is fixed to a pad 578. The bonding wire 521 extends along a direction D1 in a plan view and is aligned with the bonding wire 513 in a direction D2. The pad 578 is connected to a pad 577 via a transmission line 522 provided on the main surface 50a. One end of a bonding wire 165 (bonding wire 167 in the case of the peak amplifier 2B) shown in FIGS. 2 to 4 is fixed to the pad 577, and the pad 577 receives a first bias voltage. A first electrode of a capacitor 523 is connected to a node between the pad 577 and the pad 578. A second electrode of the capacitor 523 is connected to a pad 591. The pad 591 is connected to the reference potential pattern 15 via a via 592 penetrating the substrate 50 in the thickness direction. The bonding wire 521 straddles the capacitor 523 and the pad 591.

[0046] Pad 580 is connected to the node between pad 575 and pad 576 via capacitor 524, capacitor 525, and transmission line 531 provided on the main surface 50a. Pad 579 is connected to the node between transmission line 531 and pad 580 via wiring on the main surface 50a. One end of bonding wire 166 (bonding wire 168 in the case of peak amplifier 2B) shown in FIGS. 2 to 4 is fixed to pad 579, and pad 579 receives the second bias voltage. The first electrode of capacitor 542 is connected to the node between pad 580 and pad 579. The second electrode of capacitor 542 is connected to pad 589. Pad 589 is connected to the reference potential pattern 15 via via 590 penetrating the substrate 50 in the thickness direction.

[0047] The first end of bonding wire 532 is fixed to pad 580, and the second end of bonding wire 532 is fixed to pad 581. Bonding wire 532 extends along direction D1 in a plan view and is close to the wiring connecting pad 580 and pad 579 in a plan view. The shortest distance in the plan view between the wiring connecting pad 580 and pad 579 and bonding wire 532 is shorter than the distance between wirings provided on the main surface 50a. Bonding wire 532 is aligned with bonding wires 521 and 513 in direction D2.

[0048] Pad 582 is connected to pad 581 via transmission line 533 provided on the main surface 50a. Transmission line 533 is bent several times on the main surface 50a to ensure a sufficient length for impedance matching. One end of bonding wire 27 shown in FIGS. 2 to 4 is fixed to pad 582.

[0049] One end of each of the bonding wires 28 and 29 shown in FIG. 4 is fixed to each of the pads 583 and 586. The first electrodes of the capacitors 551 and 561 are connected to the pads 583 and 586 respectively. The second electrodes of the capacitors 551 and 561 are connected to the pads 584 and 587 respectively. Each of the pads 584 and 587 is connected to the reference potential pattern 15 through each of the vias 585 and 588 that penetrate the substrate 50 in the thickness direction.

[0050] The effects obtained by the circuit devices 3 and 5 of the present embodiment described above will be described together with the problems of the circuit devices of the comparative examples. FIG. 8 is a plan view showing a circuit device 3A according to a comparative example. This circuit device 3A is different from the circuit device 3 of the present embodiment in the following points. That is, the circuit device 3A does not include the bonding wires 36, 37, and 38, and the pad 301, the pad 310, the capacitor 31, and the capacitor 33 are connected to each other through the wiring provided on the main surface 30a. Further, FIG. 9 is a plan view showing a circuit device 5A according to a comparative example. This circuit device 5A is different from the circuit device 5 of the present embodiment in the following points. That is, the circuit device 5A does not include the bonding wires 513, 521, and 532, and the pad 571, the pad 577, the pad 579, the pad 582, the capacitor 511, and the capacitor 542 are connected to each other through the wiring provided on the main surface 50a.

[0051] FIG. 10 is a diagram schematically showing the configuration of a main amplifier 100 of a Doherty amplifier including circuit devices 3A and 5A. When designing the main amplifier 100, it is important to (1) make the impedance as seen from the direction of arrow Q1 from position F1 close to the impedance of transistor 4 (i.e., S11) as seen from the direction of arrow Q2 from position F2. Further, it is important to (2) make the load impedance of transistor 4 as seen from the direction of arrow Q3 from position F3 close to the impedance of transistor 6 (i.e., S11) as seen from the direction of arrow Q4 from position F4. Each of part (a) and part (b) of FIG. 11 is a Smith chart regarding the above (1) and (2) respectively. In part (a) of FIG. 11, plot P1 represents the S11 of transistor 4 at position F2, and plot P2 represents the impedance at position F1. In part (b) of FIG. 11, plot P3 represents the S11 of transistor 6 at position F4, and plot P4 represents the impedance at position F3. Circuit device 3A brings plot P1 shown in part (a) of FIG. 11 closer to plot P2. Circuit device 5A brings plot P3 shown in part (b) of FIG. 11 closer to plot P4. Usually, the magnitude of the signal amplified by transistor 6, which is the second-stage transistor, is larger than the magnitude of the signal amplified by transistor 4, which is the first-stage transistor. Therefore, the moving distance from plot P1 to plot P2 is longer than the moving distance from plot P3 to plot P4. And the longer this moving distance is, the longer the transmission line in the matching circuit becomes, leading to an increase in the size of the matching circuit. The increase in the size of the matching circuit leads to an increase in the size of the Doherty amplifier.

[0052] In response to such problems, the circuit device 3 of the present embodiment has bonding wires 36, 37, 38 as internal wirings of a matching circuit that are completed on the main surface 30a. The bonding wires 36, 37, 38 respectively replace the wiring portions A1, A2, A3 shown in FIG. 8. Further, the circuit device 5 of the present embodiment has bonding wires 513, 521, 532 as internal wirings of a matching circuit that are completed on the main surface 50a. The bonding wires 513, 521, 532 respectively replace the wiring portions B1, B2, B3 shown in FIG. 9.

[0053] Compared with transmission lines, bonding wires can be arranged close to other elements (other portions of the transmission line and capacitors, etc.) constituting the matching circuit in a plan view, or can straddle the other elements. Therefore, even when the transmission line becomes long, by replacing a part of the transmission line with a bonding wire, the area for laying the transmission line can be reduced. Therefore, according to the circuit devices 3 and 5 of the present embodiment, the circuit device can be miniaturized even when the transmission line becomes long.

[0054] As in the present embodiment, the bonding wires 36, 37, 38, 513, 521, 532 may straddle other elements included in the matching circuit. In that case, since the space on the other elements is utilized, the area for laying the transmission line can be made smaller, and the circuit devices 3 and 5 can be further miniaturized.

[0055] As in the present embodiment, the matching circuit has filters (low-pass filter 3a, low-pass filter 51, high-pass filter 52), and the bonding wires 36, 37, 513, 521 may constitute a part of the filter. In that case, since the area on the main surface 30a (or 50a) required for the filter can be reduced, the circuit devices 3 and 5 can be miniaturized.

[0056] As in this embodiment, the matching circuit has delay lines 3b and 53, and the bonding wires 38 and 532 may form part of the delay lines. In that case, the area on the main surface 30a (or 50a) required for the delay lines can be reduced, so that the circuit devices 3 and 5 can be miniaturized.

[0057] As in this embodiment, the matching circuit has transmission lines 32, 35, 512, 522, 531, and 533, and the bonding wires 36, 37, 38, 513, 521, and 532 may be connected in series with any of these transmission lines 32, 35, 512, 522, 531, and 533. In this way, by connecting the bonding wire in series with the transmission line, another transmission line connected to the transmission line, that is, a part of the transmission line, can be replaced with the bonding wire. Therefore, the area for laying the transmission line can be reduced.

[0058] [Modification Example] In the above-described embodiment, the extending direction in plan view of the bonding wires 36, 37, 38, 513, 521, and 532 of the main amplifier 2A is aligned with the extending direction in plan view of the bonding wires 36, 37, 38, 513, 521, and 532 of the peak amplifier 2B. However, the present invention is not limited to this form, and the extending direction in plan view of the bonding wires 36, 37, 38, 513, 521, and 532 may be different between the main amplifier 2A and the peak amplifier 2B.

[0059] FIG. 12 is a plan view showing a Doherty amplifier 1A as an example. In FIG. 12, when viewed from the normal direction of the main surface 30a, the bonding wires 36, 37, 38 of the circuit device 3 (first circuit device) of the main amplifier 2A extend along the direction D2 in a plan view. On the other hand, when viewed from the normal direction of the main surface 30a, the bonding wires 36, 37, 38 of the circuit device 3 (second circuit device) of the peak amplifier 2B extend along the direction D1 in a plan view. For example, in this way, the extending direction of the bonding wires 36, 37, 38 of the circuit device 3 of the main amplifier 2A when viewed from the normal direction of the main surface 30a may intersect with the extending direction of the bonding wires 36, 37, 38 of the circuit device 3 of the peak amplifier 2B when viewed from the same direction. In that case, crosstalk between the circuit device 3 of the main amplifier 2A and the circuit device 3 of the peak amplifier 2B can be reduced.

[0060] Similarly, in FIG. 12, when viewed from the normal direction of the main surface 50a, the bonding wires 513, 521, 532 of the circuit device 5 (first circuit device) of the main amplifier 2A extend along the direction D2 in a plan view. On the other hand, when viewed from the normal direction of the main surface 50a, the bonding wires 513, 521, 532 of the circuit device 5 (second circuit device) of the peak amplifier 2B extend along the direction D1 in a plan view. For example, in this way, the extending direction of the bonding wires 513, 521, 532 of the circuit device 5 of the main amplifier 2A when viewed from the normal direction of the main surface 50a may intersect with the extending direction of the bonding wires 513, 521, 532 of the circuit device 5 of the peak amplifier 2B when viewed from the same direction. In that case, crosstalk between the circuit device 5 of the main amplifier 2A and the circuit device 5 of the peak amplifier 2B can be reduced.

[0061] Parts (a) to (f) of FIG. 13 schematically show variations in the relationship between the extending directions of the bonding wires 36, 37, 38, 513, 521, 532 of the circuit devices 3, 5 of the main amplifier 2A and the extending directions of the bonding wires 36, 37, 38, 513, 521, 532 of the circuit devices 3, 5 of the peak amplifier 2B. Part (a) and part (b) of FIG. 13 show the case where the extending directions of the bonding wires 36, 37, 38, 513, 521, 532 of the main amplifier 2A and the peak amplifier 2B both follow the direction D1. Part (d) and part (e) of FIG. 13 show the case where the extending directions of the bonding wires 36, 37, 38, 513, 521, 532 of the main amplifier 2A and the peak amplifier 2B both follow the direction D2. Part (c) and part (f) of FIG. 13 show the case where the extending direction of the bonding wires 36, 37, 38, 513, 521, 532 of one of the main amplifier 2A and the peak amplifier 2B follows the direction D2, and the extending direction of the bonding wires 36, 37, 38, 513, 521, 532 of the other of the main amplifier 2A and the peak amplifier 2B follows the direction D1.

[0062] FIG. 14 is a side view of the bonding wires 36, 37, 38, 513, 521, 532. As shown in FIG. 14, the bonding wires 36, 37, 38, 513, 521, 532 have a starting end G1 and an ending end G2. The starting end G1 is the part where the bonding wire starts, and the ending end G2 is the part where the bonding wire ends. And the bonding wires 36, 37, 38, 513, 521, 532 have a portion H1 including the starting end G1 and a portion H2 including the ending end G2. The inclination angle θ1 of the portion H1 with respect to the main surface 30a (or 50a) is larger than the inclination angle θ2 of the portion H2 with respect to the main surface 30a (or 50a).

[0063] Referring to FIG. 13 again. In the form shown in part (a) of FIG. 13, the bonding wires 36, 37, 38, 513, 521, 532 of the main amplifier 2A are formed such that the portion H1 with a large inclination angle is closer to the peak amplifier 2B than the portion H2 with a small inclination angle. Similarly, the bonding wires 36, 37, 38, 513, 521, 532 of the peak amplifier 2B are formed such that the portion H1 with a large inclination angle is closer to the main amplifier 2A than the portion H2 with a small inclination angle. In this case, since the bonding wires of the main amplifier 2A and the bonding wires of the peak amplifier 2B are parallel while being close to each other over a long distance, the crosstalk between the main amplifier 2A and the peak amplifier 2B increases.

[0064] Also, in the form shown in part (b) of FIG. 13, the bonding wires 36, 37, 38, 513, 521, 532 of the main amplifier 2A are formed such that the portion H2 with a small inclination angle is closer to the peak amplifier 2B than the portion H1 with a large inclination angle. Similarly, the bonding wires 36, 37, 38, 513, 521, 532 of the peak amplifier 2B are formed such that the portion H2 with a small inclination angle is closer to the main amplifier 2A than the portion H1 with a large inclination angle. In this case, since the bonding wires of the main amplifier 2A and the bonding wires of the peak amplifier 2B are not parallel, the crosstalk between the main amplifier 2A and the peak amplifier 2B is reduced as compared with the form of part (a) of FIG. 13. However, since the extending directions of the bonding wires are the same for the main amplifier 2A and the peak amplifier 2B, some crosstalk occurs.

[0065] In the form shown in part (d) of FIG. 13, the orientations of the arrangement of the portion H2 with respect to the portion H1 in the direction D2 are aligned with each other for the main amplifier 2A and the peak amplifier 2B. In this case, since the bonding wires of the main amplifier 2A and the bonding wires of the peak amplifier 2B are parallel over a long distance, the crosstalk between the main amplifier 2A and the peak amplifier 2B increases.

[0066] In the form shown in part (e) of FIG. 13, the orientation of the arrangement of portion H2 with respect to portion H1 in direction D2 is opposite between main amplifier 2A and peak amplifier 2B. In this case, since the bonding wires of main amplifier 2A and the bonding wires of peak amplifier 2B are not parallel, crosstalk between main amplifier 2A and peak amplifier 2B is reduced as compared with the form of part (d) of FIG. 13. However, since the extending directions of the bonding wires are the same for main amplifier 2A and peak amplifier 2B, some crosstalk occurs.

[0067] In the form shown in part (c) of FIG. 13, the bonding wires 36, 37, 38, 513, 521, 532 of peak amplifier 2B are formed such that the portion H1 with a large tilt angle is closer to main amplifier 2A than the portion H2 with a small tilt angle. However, in the form shown in part (c) of FIG. 13, since the extending direction of the bonding wires of main amplifier 2A and the extending direction of the bonding wires of peak amplifier 2B intersect each other, even though the portion H1 of the bonding wires of peak amplifier 2B is arranged closer to main amplifier 2A, the crosstalk between main amplifier 2A and peak amplifier 2B is reduced as compared with the forms of parts (a) and (d) of FIG. 13.

[0068] In the form shown in part (f) of FIG. 13, the bonding wires 36, 37, 38, 513, 521, 532 of peak amplifier 2B are formed such that the portion H2 with a small tilt angle is closer to main amplifier 2A than the portion H1 with a large tilt angle. Thus, by moving the portion H1 with a large tilt angle away from main amplifier 2A, the crosstalk between main amplifier 2A and peak amplifier 2B is further reduced. That is, the form shown in part (f) of FIG. 13 is the form that can most reduce the crosstalk between main amplifier 2A and peak amplifier 2B.

[0069] As shown in part (f) of FIG. 13, when the bonding wires of the circuit devices 3 and 5 of the main amplifier 2A are along the direction D2 and the bonding wires of the circuit devices 3 and 5 of the peak amplifier 2B are along the direction D1, in the bonding wires of the circuit devices 3 and 5 of the peak amplifier 2B, the portion H2 with a small tilt angle may be located closer to the bonding wire of the main amplifier 2A, and the portion H1 with a large tilt angle may be located farther away from the bonding wire of the main amplifier 2A. In that case, crosstalk between the circuit devices 3 and 5 of the main amplifier 2A and the circuit devices 3 and 5 of the peak amplifier 2B can be further reduced.

Explanation of Signs

[0070] 1, 1A… Doherty amplifier 2A… Main amplifier 2B… Peak amplifier 3, 3A, 5, 5A… Circuit devices 3a… Low-pass filter 3b… Delay line 4, 6… Transistor 10… Base 11… Main surface 14… Resin body 15… Reference potential pattern 24… Transistor 25~29… Bonding wire 30… Substrate 30a… Main surface 31, 33… Capacitor 32, 35… Transmission line 34… Resistor 36~38… Bonding wire 50… Substrate 50a… Main surface 51… Low-pass filter 52… High-pass filter 53… Delay line 54… Bias circuit 55, 56… Harmonic processing circuit 100… Main amplifier 121~128… Wiring 131~138… Pad 161~168... Bonding wire 301, 302, 304~311... Pad 303, 312... Via 511... Capacitor 512, 522, 531, 533... Transmission line 513, 521, 532... Bonding wire 523~525, 542, 551, 552, 561... Capacitor 541... Resistor 571~573, 575~584, 586, 587, 589, 591... Pad 574, 585, 588, 590, 592... Via A1~A3, B1~B3... Wiring part D1, D2... Direction F1~F4... Position G1... Start end G2... End end H1, H2... Part P1~P4... Plot Q1~Q4... Arrow θ1, θ2... Inclination angle

Claims

1. A circuit device for impedance matching with a transistor, comprising a substrate having a main surface, a matching circuit provided on the main surface and connected to an input terminal or an output terminal of the transistor to perform impedance matching with the transistor, and the matching circuit has bonding wires as internal wiring of the matching circuit that are self - contained on the main surface.

2. The circuit device according to claim 1, wherein the bonding wire straddles other elements included in the matching circuit.

3. The matching circuit has a filter, and the circuit device according to claim 1, wherein the bonding wire constitutes a part of the filter.

4. The filter is a low - pass filter, and in the circuit device according to claim 3, a first end of the bonding wire is connected to an input end of the low - pass filter, and a second end of the bonding wire is connected to an output end of the low - pass filter.

5. The filter is a high - pass filter, and the circuit device according to claim 3, wherein the bonding wire constitutes a part of a bias wiring provided in the high - pass filter.

6. The matching circuit has a delay line, and the circuit device according to claim 1, wherein the bonding wire constitutes a part of the delay line.

7. The matching circuit has a transmission line, and the circuit device according to claim 1, wherein the bonding wire is connected in series with the transmission line.

8. A Doherty amplifier comprising a main amplifier and a peak amplifier, The main amplifier has a first circuit device which is the circuit device according to any one of claims 1 to 7. The peak amplifier has a second circuit device which is the circuit device according to any one of claims 1 to 7. The first circuit device is arranged side by side with the second circuit device in a first direction. A Doherty amplifier in which a extending direction of the bonding wire of the first circuit device, as viewed from a normal direction of the main surface, intersects with a extending direction of the bonding wire of the second circuit device, as viewed from the same direction.

9. One of the bonding wires of the first circuit device and the bonding wire of the second circuit device is along the first direction. The other bonding wire of the first circuit device and the bonding wire of the second circuit device is along a second direction intersecting with the first direction. The one bonding wire includes a first portion closer to the other bonding wire and a second portion farther from the other bonding wire than the first portion. The Doherty amplifier according to claim 8, wherein an inclination angle of the second portion with respect to the main surface is larger than an inclination angle of the first portion with respect to the main surface.

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