JP2017126701A - Photoelectric converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photoelectric converter having a wide frequency bandwidth and flat frequency characteristics.SOLUTION: A photoelectric converter for converting an optical signal into an electric signal and amplifying includes a photoelectric conversion element 10 for converting an optical signal into an electric signal and outputting, a high frequency amplifier 20 for amplifying the electric signal outputted from the photoelectric conversion element, and an adjustment circuit 30 placed between the photoelectric conversion element and high frequency amplifier, and matching the photoelectric conversion element and high frequency amplifier. The adjustment circuit is adjusted so that the Q value falls in a range of 2-5.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a photoelectric converter that converts an optical signal into an electric signal and amplifies it, and more particularly to a narrow-band photoelectric converter.

  A photoelectric converter is a key device for optical wireless communication in the microwave and millimeter wave bands. This photoelectric converter receives an optical signal transmitted from a base station through an optical cable, converts it into an electrical signal, and outputs it to an antenna. The quality of the transmitted signal is expected to vary, and the performance required for narrow-band photoelectric converters includes high photoelectric conversion efficiency, high RF output, high RF output linearity (the output signal of the amplifier circuit is the input signal) The conversion performance from light to electricity is important.

  On the other hand, as another important factor, there is a frequency characteristic in a specific microwave and millimeter wave band. Since the data transmission capacity increases as the frequency bandwidth increases, a wide frequency bandwidth and flat frequency characteristics are required at a specific frequency not only on the transmission side but also on the reception side, that is, on the photoelectric converter.

  In general, in order to widen the frequency bandwidth, it is advantageous to increase the center frequency (carrier frequency). This is because a width of about 20% with respect to the center frequency is obtained as the frequency bandwidth. That is, when the center frequency is 10 GHz, the frequency bandwidth is about 2 GHz. However, when the center frequency is 100 GHz, the frequency bandwidth is about 20 GHz and the frequency bandwidth is widened.

  Currently, there are very few products and research reports of narrow-band photo receivers in the microwave and millimeter wave bands used for optical fiber wireless applications. However, as a conventional technique, a photoelectric converter (photomixer) including only a single photodiode without an RF amplifier has been commercialized. The center frequency of this photoelectric converter is 100 GHz (gigahertz), the -3 dB band from the maximum gain is 35 GHz, and the bandwidth ratio to the center frequency is about 35%. However, there is a disadvantage that the photoelectric conversion efficiency is low because no RF (high frequency) amplifier is connected to the subsequent stage.

  Non-Patent Document 1 reports a narrow-band photoelectric converter having a built-in 60 GHz band RF (high frequency) amplifier. In this photoelectric converter, the -3 dB band from the maximum gain in the 60 GHz band is 10 GHz, and the bandwidth ratio with respect to the center frequency 55 GHz is about 18%, and has high conversion efficiency. This is largely due to the characteristics of the used RF amplifier itself as well as the characteristics between the photodiode and the RF amplifier.

  Further, in Patent Document 1, in an optical receiver using a photodiode as a light receiving element, a frequency tuning circuit that inputs an RF output signal of the photodiode, an output terminal of the frequency tuning circuit, and an input in a subsequent amplifier A photoelectric converter including a buffer resistor connected between the ends has been proposed.

JP-A-8-191278

S. Fedderwitz, C.C.Leonhardt, J.Honecker, P.Muller, and A.G.Steffan, “A high power 60GHz photoreceiver”, Tech. Dig. Of OFC / NFOEC2012

  As described above, a wide frequency bandwidth and flat frequency characteristics are required. However, in the photoelectric converter proposed in Non-Patent Document 1, a bandwidth ratio with respect to the center frequency of 55 GHz is about 18%, which is high. Although it has conversion efficiency, there is a problem that it is largely caused by the characteristics between the photodiode and the RF amplifier in addition to the performance of the used RF amplifier itself, so that it cannot be applied.

  Further, in the photoelectric converter proposed in Patent Document 1, a frequency tuning circuit for inputting an RF output signal of a photodiode is provided to enhance an RF signal output in a high frequency region of a light modulation frequency. If the Q value is not optimized, impedance mismatch with the subsequent preamplifier is large, and the oscillation tendency is increased.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a photoelectric converter having a wide frequency bandwidth and a flat frequency characteristic.

  The photoelectric converter according to the present invention is a photoelectric converter that converts an optical signal into an electric signal and amplifies the photoelectric converter, converts the optical signal into an electric signal, and outputs the electric signal; and outputs from the photoelectric conversion element A high-frequency amplifier that amplifies the electrical signal, and an adjustment circuit that is disposed between the photoelectric conversion element and the high-frequency amplifier and performs matching between the photoelectric conversion element and the high-frequency amplifier, The Q value is adjusted to be in the range of 2-5.

  According to said structure, it arrange | positions between the photoelectric conversion element which converts an optical signal into an electrical signal, outputs, the high frequency amplifier which amplifies the electrical signal output from a photoelectric conversion element, and a photoelectric conversion element and a high frequency amplifier And an adjustment circuit that performs matching between the photoelectric conversion element and the high-frequency amplifier, and the adjustment circuit adjusts the Q value to be in the range of 2 to 5, so that it has a wide frequency bandwidth and a flat frequency. A photoelectric converter having characteristics can be provided.

  In addition, the adjustment circuit is arranged not between the high-frequency amplifier but between the photoelectric conversion element and the high-frequency amplifier, so that adjustment of the electrical signal is performed before amplification by the high-frequency amplifier, thereby suppressing unnecessary signal amplification. Thus, a highly efficient photoelectric converter with low power loss can be obtained.

  The adjustment circuit of the photoelectric converter according to the present invention is adjusted so that VSWR (standing wave ratio) is 3 or less.

  According to the above configuration, the adjustment circuit is adjusted so that the VSWR (standing wave ratio) is 3 or less, so that it is possible to provide a highly efficient photoelectric converter with low power loss.

  The adjustment circuit of the photoelectric converter according to the present invention includes an LC circuit having a coil and a capacitor.

  According to said structure, since an adjustment circuit can be comprised with a general circuit, manufacturing cost can be suppressed and it contributes to stabilization of manufacture.

  The adjustment circuit of the photoelectric converter according to the present invention includes a stub.

  According to said structure, since an adjustment circuit can be comprised with a general circuit, manufacturing cost can be suppressed and it contributes to stabilization of manufacture.

  The high-frequency amplifier of the photoelectric converter according to the present invention is a narrow-band amplifier that amplifies a specific band among bands of 30 GHz (gigahertz) or more.

  According to said structure, since it applies to the 30 GHz (gigahertz) or more zone | band which a frequency characteristic tends to deteriorate, a frequency characteristic can be improved more effectively.

  In the photoelectric converter according to the present invention, the photoelectric conversion element, the high-frequency amplifier, and the adjustment circuit are connected to each other by a flip-chip mounted bump, a bonding wire, or a through electrode.

  According to said structure, the photoelectric conversion element, the high frequency amplifier, and the adjustment circuit are connected by either the bump by a flip-chip mounting, the bonding wire, or the penetration electrode. For this reason, the inductance between the photoelectric conversion element, the high frequency amplifier and the adjustment circuit can be reduced, and the power loss can be effectively reduced. Also, the frequency characteristics are good. Moreover, by setting it as the said structure, the number of parts and assembly man-hours of a photoelectric converter can be reduced, As a result, the manufacturing cost of photoelectric converter (photo receiver module) manufacture can be reduced.

  According to the present invention, it is possible to provide a photoelectric converter having a wide frequency bandwidth and flat frequency characteristics.

It is a circuit diagram of the photoelectric converter which concerns on embodiment. It is a figure which shows an example of the adjustment circuit of the photoelectric converter which concerns on embodiment. It is another figure which shows an example of the adjustment circuit of the photoelectric converter which concerns on embodiment. It is a block diagram which shows the connection method of the photoelectric converter which concerns on embodiment. It is a figure which shows the simulation result of the frequency characteristic of the photoelectric converter which concerns on an Example. It is a figure which shows the simulation result of the optical wireless transmission of the photoelectric converter which concerns on an Example. It is a figure which shows the simulation result of the other optical wireless transmission of the photoelectric converter which concerns on an Example.

(Embodiment)
FIG. 1 is a circuit diagram of the photoelectric converter according to the embodiment. 2 and 3 are diagrams illustrating an example of the adjustment circuit of the photoelectric converter according to the embodiment. Hereinafter, the configuration of the photoelectric converter according to the present embodiment will be described with reference to FIGS. 1 to 3.

  As shown in FIG. 1, the photoelectric converter (photo receiver) according to this embodiment includes a photoelectric conversion element 10, a high-frequency amplifier 20, and an adjustment circuit 30. The photoelectric conversion element 10 is, for example, a photodiode, which converts an optical signal into an electric signal and outputs it.

  The high frequency amplifier 20 is, for example, an RF (high frequency) amplifier, and is an amplifier that amplifies an electric signal output from the photoelectric conversion element 10. Here, the high-frequency amplifier 20 is a narrow-band amplifier that amplifies a specific band in a band of 30 GHz (gigahertz) or more. By applying to a band of 30 GHz (gigahertz) or more where the frequency characteristics are likely to deteriorate, the frequency characteristics can be effectively improved.

  The adjustment circuit 30 is disposed between the photoelectric conversion element 10 and the high-frequency amplifier 20 and performs impedance matching between the photoelectric conversion element 10 and the high-frequency amplifier 20. Here, the adjustment circuit 30 is preferably adjusted so that the Q value falls within the range of 2 to 5. By adjusting the adjustment circuit 30 so that the Q value falls within the range of 2 to 5, a photoelectric converter having a wide frequency bandwidth and a flat frequency characteristic can be provided.

  Further, by arranging the adjustment circuit 30 between the photoelectric conversion element 10 and the high-frequency amplifier 20 instead of following the high-frequency amplifier 20, the electric signal is adjusted before the amplification by the high-frequency amplifier 20, thereby reducing power loss. A low and highly efficient photoelectric converter can be obtained.

  Furthermore, the adjustment circuit 30 preferably adjusts the VSWR (standing wave ratio) to be 3 or less. By adjusting the VSWR (standing wave ratio) of the adjustment circuit 30 to be 3 or less, amplification of unnecessary signals can be suppressed, and a highly efficient photoelectric converter with low power loss can be provided.

  The electric signal transmission path has the property that the power obtained in the receiving circuit is maximized by setting the sending side voltage constant and making the output impedance of the circuit equal to the input impedance of the receiving circuit. Therefore, in order to perform transmission efficiently, it is necessary to equalize (match) their impedances.

  If the impedance is not matched, not only the desired maximum output cannot be taken out, but also a high-frequency circuit may generate a reflected wave in the transmission line and be superposed with a traveling wave, resulting in inconvenience. In the present embodiment, the above problem is solved by performing impedance matching between the photoelectric conversion element 10 and the high-frequency amplifier 20 by the adjustment circuit 30.

  FIG. 2 is a diagram illustrating an example in which the adjustment circuit 30 is configured by an LC circuit having a coil and a capacitor. The LC circuit is a kind of resonant circuit and is an electric circuit composed of a coil L and a capacitor C. In this case, as shown in FIG. 2, the adjustment circuit 30 includes a circuit in which one or more coils L and one or more capacitors C are connected. 2A shows a serial LC circuit, and FIG. 2B shows a parallel LC circuit.

  In the present embodiment, it is sufficient that impedance matching is achieved only in a narrow band, and therefore a matching circuit using a combination of a coil L and a capacitor C can be used as shown in FIG. The photoelectric conversion element 10 and the high-frequency amplifier 20 are matched by adjusting the ratio of the capacitor C and the coil L. However, since this is a high-frequency circuit, it is necessary to match the impedance (reactance component) of the imaginary part. is necessary.

  Here, in order to adjust the Q value and the VSWR (standing wave ratio) of the adjustment circuit 30, it is necessary to design an LC circuit. The design method includes a method based on desktop calculation and a method using a Smith chart. Recently, there are a method using a circuit simulator, a method using a network analyzer, and the like.

The LC circuit includes a serial LC circuit (see FIG. 2A) and a parallel LC circuit (see FIG. 2B). In the case of a series LC circuit, the impedance Z is expressed by the following equation (1).
... (1)
ω: angular velocity L: inductance C: capacitance j: imaginary number

In the case of a parallel LC circuit, the impedance Z is expressed by the following equation (2).
... (2)
ω: angular velocity L: inductance C: capacitance j: imaginary number

  FIG. 3 is a diagram illustrating an example in which the adjustment circuit 30 is configured by a stub circuit. A stub is a distributed constant line connected in parallel to a transmission line in a high-frequency circuit. For distributed constant lines, depending on the termination load and the ratio of the line length to the wavelength, it becomes a capacitor or an inductor when viewed from the input end, so it should be used as a substitute for capacitors and coils for impedance matching in high-frequency circuits. Can do.

  Depending on the type of terminal load (resistance), the one with the open end is called an open stub, and the one with the shorted end is called a short stub. In the example shown in FIG. 3, two stubs S1 and S2 connected in series between the photoelectric conversion element 10 and the high-frequency amplifier 20, that is, an electric signal transmission line, and one end are connected between the stubs S1 and S2. The adjustment circuit 30 is configured by a stub S3 whose one end is short-circuited (grounded), one end connected between the stub S2 and the high-frequency amplifier 20, and the other end short-circuited (grounded).

  Here, the circuit example shown in FIG. 3 is a short stub type circuit because the end of the terminal load (resistance) is short-circuited (grounded). Note that the stubs S1 to S3 are distributed constant lines, and are realized by, for example, microstrip lines formed on a wiring board.

  By configuring the adjustment circuit 30 with a general circuit such as an LC circuit or a stub having a coil and a capacitor, the manufacturing cost can be suppressed, which contributes to the stabilization of manufacturing. The circuits shown in FIGS. 2 and 3 are examples of the adjustment circuit 30 and are not limited to the examples shown in FIGS. The adjustment circuit 30 can also be realized by a circuit other than the circuits shown in FIGS.

  As described above, the photoelectric converter according to this embodiment is characterized in that an adjustment circuit including an LC circuit or a stub circuit is provided between the photoelectric conversion element 10 and the high-frequency amplifier 20. When the photoelectric conversion element 10 and the high frequency amplifier 20 are directly connected, mismatch between the output impedance of the photoelectric conversion element 10 and the input impedance of the high frequency amplifier 20 is likely to occur, and it is difficult to control the frequency characteristics.

  In particular, the output impedance of the photoelectric conversion element 10 is high, and the high-frequency amplifier 20 is mainly impedance-matched only at the center frequency, and the impedance is not matched to 50Ω (ohms) at other frequencies, and the return loss. (Ratio of reflected power to input power) increases. It is difficult to control the frequency characteristics to be as flat as possible under such conditions. For this reason, in the photoelectric converter according to the present embodiment, an adjustment circuit configured by an LC circuit or a stub circuit is provided between the photoelectric conversion element 10 and the high-frequency amplifier 20.

  When the adjustment circuit 30 is configured to have a Q value of about 5, the gain is improved through the photoelectric conversion element 10, the adjustment circuit 30, and the high-frequency amplifier 20. Further, when the adjustment circuit 30 is configured to have a Q value of about 1, when Q is close to 1, the frequency band is widened. For this reason, in the photoelectric converter according to the present embodiment, the Q value is approximately 2 to 5 and is gently resonated. When the Q value is too high, the function of the high frequency amplifier 20 tends to oscillate, and the function as a module is lost. Further, VSWR (standing wave ratio) 3 indicates a value that does not cause oscillation due to the action with the high-frequency amplifier 20.

  In the photoelectric converter according to this embodiment, as shown in FIG. 4, the photoelectric conversion element 10, the high-frequency amplifier 20, and the adjustment circuit 30 are connected by any one of flip-chip mounting, wire bonding, and through electrodes. It is preferable. 4A, the semiconductor chip in which the circuit of the photoelectric conversion element 10 is formed, the semiconductor chip in which the circuit of the high-frequency amplifier 20 is formed, and the semiconductor chip in which the adjustment circuit 30 is formed are connected by wire bonding. It is a figure which shows an example.

  In the example shown in FIG. 4A, the input end, the output end, and the ground terminal included in the photoelectric conversion element 10, the high frequency amplifier 20, and the adjustment circuit 30 are connected by bonding wires W, respectively. The semiconductor chip on which the circuit of the photoelectric conversion element 10 is formed, the semiconductor chip on which the circuit of the high-frequency amplifier 20 is formed, and the semiconductor chip on which the adjustment circuit 30 is formed are stacked via a spacer, and then input terminals The output terminal and the ground terminal may be connected by a bonding wire W, respectively.

  In FIG. 4B, the semiconductor chip in which the circuit of the photoelectric conversion element 10 is formed, the semiconductor chip in which the circuit of the high-frequency amplifier 20 is formed, and the semiconductor chip in which the adjustment circuit 30 is formed are connected by flip-chip connection. FIG. In the example shown in FIG. 4B, the input end, the output end, and the ground terminal included in the photoelectric conversion element 10, the high-frequency amplifier 20, and the adjustment circuit 30 are connected by a bump B.

  In FIG. 4C, the semiconductor chip in which the circuit of the photoelectric conversion element 10 is formed, the semiconductor chip in which the circuit of the high frequency amplifier 20 is formed, and the semiconductor chip in which the adjustment circuit 30 is formed are formed by the Si through electrode TSV. It is a figure which shows the example connected. In the example shown in FIG. 4C, the input end, the output end, and the ground terminal included in the photoelectric conversion element 10, the high-frequency amplifier 20, and the adjustment circuit 30 are connected by the Si through electrode TSV.

  As described with reference to FIG. 4, the photoelectric conversion element 10, the high-frequency amplifier 20, and the adjustment circuit 30 are connected by a flip-chip mounting, wire bonding, or through electrode method, so that the photoelectric conversion element 10. The inductance between the high-frequency amplifier 20 and the adjustment circuit 30 can be reduced, and the frequency characteristics of the photoelectric converter are improved. In addition, by adopting the configuration shown in FIG. 4, the number of parts and assembly man-hours of the photoelectric converter can be reduced, and as a result, the manufacturing cost for manufacturing the photoelectric converter (photo receiver module) can be reduced.

(Comparison of frequency characteristics)
FIG. 5 is a simulation result of frequency characteristics of the photoelectric converter according to the example. The horizontal axis of Fig.5 (a) is a frequency (GHz). The vertical axis in FIG. 5A is the gain (dB) including the photoelectric conversion element 10 and the high-frequency amplifier 20. Moreover, the horizontal axis of FIG.5 (b) is a frequency (GHz). The vertical axis | shaft of FIG.5 (b) is a phase (degree). The simulation result shown in FIG. 5 is a result when the center frequency is 30 GHz.

  The broken line graph in FIG. 5 is the simulation result of the photoelectric converter described with reference to FIG. That is, the adjustment circuit 30 is disposed between the photoelectric conversion element 10 and the high-frequency amplifier 20, and matching between the photoelectric conversion element 10 and the high-frequency amplifier 20 is adjusted. The adjustment circuit 30 includes the stub described with reference to FIG. The adjustment circuit 30 (modified stub) was adjusted such that the Q value was lowered and the VSWR (standing wave ratio) was about 3 (return loss was −6 db).

  Moreover, the solid line graph in FIG. 5 is the simulation result of the frequency characteristics of the conventional photoelectric converter. That is, the adjustment circuit 30 is not disposed between the photoelectric conversion element 10 and the high-frequency amplifier 20, and matching between the photoelectric conversion element 10 and the high-frequency amplifier 20 is not adjusted. The solid line graph shows an example in which the Q value is adjusted to be relatively large by the inductance. Here, the Q value is 4.4 when trimming is not performed (without the adjustment circuit 30), and when trimming is performed (adjustment circuit 30). Yes) and about 2.5.

  From the simulation result of FIG. 5B, when there is no adjustment circuit 30 (solid line), the frequency band in which the phase difference can be maintained within 50 ° is as narrow as 7 GHz, but when the adjustment circuit 30 is arranged (broken line) It can be seen that the frequency band in which the phase difference can be kept within 50 ° is as wide as 11.8 GHz. In terms of the bandwidth ratio with respect to the center frequency of 30 GHz, this is 23% when the adjustment circuit 30 is not provided (solid line), and 39% when the adjustment circuit 30 is provided (broken line).

(Comparison of optical wireless transmission)
6 and 7 are simulation results of optical wireless transmission of the photoelectric converter according to the example. FIG. 6 shows a simulation result when the adjustment circuit 30 is not provided. FIG. 7 shows a simulation result when the adjustment circuit 30 is provided.

  In the following simulation, the center frequency was 30 GHz. The adjustment circuit 30 is configured by the stub described with reference to FIG. Further, the adjustment circuit 30 (modified stub) is adjusted so that the Q value is lowered and the VSWR (standing wave ratio) is about 3 (return loss is −6 db).

Table 1 below shows simulation results when the adjustment circuit 30 is not provided and when the adjustment circuit 30 is provided.

  As shown in Table 1, it was found that the transmission symbol rate (Gbaud) can be improved from 6 to 8.4 by providing the adjustment circuit 30 between the photoelectric conversion element 10 and the high-frequency amplifier 20. It was also confirmed that the modulation system can be multi-valued from 16QAM to 64QAM.

  As described above, the photoelectric converter according to the present embodiment is a photoelectric converter that converts an optical signal into an electrical signal and amplifies the photoelectric converter 10 that converts the optical signal into an electrical signal and outputs the electrical signal. A high-frequency amplifier 20 that amplifies an electrical signal output from the photoelectric conversion element, and an adjustment circuit 30 that is disposed between the photoelectric conversion element 10 and the high-frequency amplifier 20 and performs matching between the photoelectric conversion element 10 and the high-frequency amplifier 20. The adjustment circuit 30 is adjusted so that the Q value is in the range of 2 to 5.

  According to said structure, the photoelectric conversion element 10 which converts and outputs an optical signal into an electric signal, the high frequency amplifier 20 which amplifies the electric signal output from the photoelectric conversion element 10, the photoelectric conversion element 10 and the high frequency amplifier 20 And an adjustment circuit 30 that performs matching between the photoelectric conversion element 10 and the high-frequency amplifier 20, and is adjusted by the adjustment circuit 30 so that the Q value is in the range of 2 to 5. A photoelectric converter having a wide frequency bandwidth and flat frequency characteristics can be provided.

  Further, by arranging the adjustment circuit 30 between the photoelectric conversion element 10 and the high-frequency amplifier 20 instead of following the high-frequency amplifier 20, adjustment of an electric signal before amplification by the high-frequency amplifier 20 can be performed. Amplification is suppressed, and a highly efficient photoelectric converter with low power loss can be obtained.

  The adjustment circuit 30 of the photoelectric converter according to the present embodiment is adjusted so that the VSWR (standing wave ratio) is 3 or less.

  According to the above configuration, the adjustment circuit 30 is adjusted so that the VSWR (standing wave ratio) is 3 or less, so that it is possible to provide a highly efficient photoelectric converter with low power loss.

  The adjustment circuit 30 of the photoelectric converter according to the present embodiment is configured by an LC circuit having a coil and a capacitor.

  According to said structure, since the adjustment circuit 30 can be comprised with a general circuit, manufacturing cost can be suppressed and it contributes to stabilization of manufacture.

  The adjustment circuit 30 of the photoelectric converter according to the present embodiment is configured by a stub.

  According to said structure, since the adjustment circuit 30 can be comprised with a general circuit, manufacturing cost can be suppressed and it contributes to stabilization of manufacture.

  The high-frequency amplifier 20 of the photoelectric converter according to the present embodiment is a narrow-band amplifier that amplifies a specific band among bands of 30 GHz (gigahertz) or higher.

  According to said structure, since it applies to the 30 GHz (gigahertz) or more zone | band which a frequency characteristic tends to deteriorate, a frequency characteristic can be improved more effectively.

  In the photoelectric converter according to this embodiment, the photoelectric conversion element 10, the high-frequency amplifier 20, and the adjustment circuit 30 are connected by any one of flip-chip mounting bumps, bonding wires, or through electrodes.

  According to said structure, the photoelectric conversion element 10, the high frequency amplifier 20, and the adjustment circuit 30 are connected by either the bump B by the flip-chip mounting, the bonding wire W, or the penetration electrode TSV. For this reason, the inductance between the photoelectric conversion element 10, the high frequency amplifier 20, and the adjustment circuit 30 can be reduced, and the power loss can be effectively reduced. Also, the frequency characteristics are good. Moreover, by setting it as the said structure, the number of parts and assembly man-hours of a photoelectric converter can be reduced, As a result, the manufacturing cost of photoelectric converter (photo receiver module) manufacture can be reduced.

(Other embodiments)
In addition, this invention is not limited to embodiment mentioned above. That is, those skilled in the art may make various modifications, combinations, subcombinations, and alternatives regarding the components of the above-described embodiments within the technical scope of the present invention or an equivalent scope thereof. For example, the adjustment circuit 30 is not limited to the circuit examples illustrated in FIGS. 2 and 3, and can be realized by a circuit other than the circuit examples illustrated in FIGS. 2 and 3.

DESCRIPTION OF SYMBOLS 10 Photoelectric conversion element 20 High frequency amplifier 30 Adjustment circuit B Bump W Bonding wire TSV Si penetration electrode

Claims (6)

A photoelectric converter that converts an optical signal into an electric signal and amplifies it,
A photoelectric conversion element that converts the optical signal into an electrical signal and outputs the electrical signal;
A high-frequency amplifier that amplifies an electrical signal output from the photoelectric conversion element;
An adjustment circuit that is disposed between the photoelectric conversion element and the high-frequency amplifier and performs matching between the photoelectric conversion element and the high-frequency amplifier;
The photoelectric converter is characterized in that the adjustment circuit is adjusted so that a Q value falls within a range of 2 to 5.   The photoelectric converter according to claim 1, wherein the adjustment circuit is adjusted so that a VSWR (standing wave ratio) is 3 or less.   The photoelectric converter according to claim 1, wherein the adjustment circuit includes an LC circuit having a coil and a capacitor.   The photoelectric converter according to claim 1, wherein the adjustment circuit includes a stub.   5. The photoelectric converter according to claim 1, wherein the high-frequency amplifier is a narrow-band amplifier that amplifies a specific band in a band of 30 GHz (gigahertz) or more. The photoelectric conversion element, the high frequency amplifier and the adjustment circuit are:
6. The photoelectric converter according to claim 1, wherein the photoelectric converter is connected by any one of a flip chip mounting bump, a bonding wire, and a through electrode.