An amplification device for amplifying signals in an optical transceiver

Abstract

An amplification device in an electro-optical receiver is used to amplify a signal. An amplification device for amplifying a signal having a DC signal component is provided, which includes a coupling and filtering circuit having an input terminal and an output terminal. The coupling and filtering circuit attenuates the DC signal component of the input signal to obtain a filtered output signal. The coupling and filtering circuit includes: a first capacitor circuit connecting the input terminal to the output terminal, the first capacitor circuit including a first capacitor; a second capacitor circuit connected in parallel with the first capacitor circuit, the second capacitor circuit including a second capacitor, a first resistor, and a second resistor, the second capacitor, the first resistor, and the second resistor being connected in series; and a resistor circuit connected to the input terminal and the output terminal and including a third resistor connected to the input terminal and a fourth resistor connected to the output terminal. The amplification device includes an amplification circuit connected to the output terminal, and the amplification circuit amplifies the filtered signal.

Description

Technical Field

[0001] The present invention generally relates to the field of optical communications. More specifically, the present invention relates to an amplification device for amplifying signals for optical communications within a transceiver. Background Art

[0002] In a transmitter for optical communications, a broadband driver amplifier is used to increase the level of a high-speed digital source in order to provide sufficient power to properly drive an electro-optic modulator. In this regard, an alternating current (AC) coupling connection is required between the high-speed digital source and the driver amplifier to decouple the direct current (DC) voltage from the high-speed digital source.

[0003] Driver amplifiers with integrated AC coupling have received much attention because they greatly reduce the module size, the number of components, and the cost. Recently, the updated IEEE 802.3bs standard requires a low cutoff frequency below 300 KHz, rather than 1 MHz in the old standard. Therefore, it is advantageous to obtain driver amplifiers with integrated input AC coupling and an extended low cutoff frequency because these amplifiers enable optical modules to comply with the new standard.

[0004] Figure 1 A typical scheme of a driver amplifier 100 for implementing AC coupling in the prior art is shown. This scheme includes an RC amplifier composed of three elements: a resistor R G 101 for providing the correct bias voltage to the driver input; a capacitor C G 103 for decoupling the DC voltage from the high-speed digital source; and a resistor R1 105 for providing the correct matching impedance to the high-speed digital source.

[0005] Figure 1 The low cutoff frequency ω of the driver amplifier 100 in LCF can be estimated by the following formula:

[0006]

[0007] where R G and C G respectively represent the resistance value of the resistor 101 and the capacitance value of the capacitor 103.

[0008] According to the above formula, the low cutoff frequency can be extended (i.e., reduced) by increasing the capacitance value or the resistance value. Extending the low cutoff frequency by increasing the capacitance value of the capacitor C G will also reduce the high cutoff frequency ω of the driver amplifier HCF, thus reducing the maximum data rate supported by the driver amplifier itself. This undesirable effect is caused by the parasitic capacitance of the actual integrated metal-insulator-metal (MIM) capacitor.

[0009] Figure 2 shows a scheme of a driver amplifier 200 similar to Figure 1 , where the capacitor 201 CG is implemented by an integrated MIM capacitor. The MIM capacitor consists of two metal plates, a top plate 203 and a bottom plate 205, with an insulating material (oxide) sandwiched between the two metal plates.

[0010] The capacitance between the bottom plate 205 and the top plate 203 realizes the capacitor CG 201. However, the integrated driver amplifier also has a ground metal plate 207, which generates an undesirable capacitance effect to ground with the bottom plate 205 of the MIM capacitor. This undesirable capacitance effect can be represented by the capacitor CB 209 and is proportional to the area of the MIM capacitor.

[0011] The parasitic capacitance CB 209 affects the high cut-off frequency ω of the driver amplifier as shown in the following equation HCF :

[0012]

[0013] where, R1 represents the resistance of the resistor R1, C B represents the capacitance of the capacitor CB, R s represents the output impedance of the high-speed digital source, and C GS represents the input capacitance of the amplifier module 211.

[0014] To extend the low cut-off frequency, the area of the MIM capacitor must be increased, thus increasing the value of the capacitor CG. However, increasing the area of the MIM capacitor will also increase the value of the capacitor CB, resulting in a decrease in the high cut-off frequency ω HCF decrease.

[0015] Another possible solution in the prior art is to increase the value of the resistor R G . However, this will cause reliability problems for the driver amplifier. In fact, the actual transistors of the amplifier module that makes up the driver amplifier will suffer from leakage current from the output to the input. This leakage current flows through the resistor, generating a DC voltage at the input of the amplifier module, thus increasing the output current of the amplifier module itself.

[0016] As a result, the channel temperature of the transistors that make up the amplifier module increases, leading to reliability and lifetime risks. In summary, increasing the resistor to extend the low cut-off frequency will reduce the reliability margin and service life of the driver amplifier.

[0017] In addition, previous work did not allow the low cut-off frequency of a drive amplifier to be extended without reducing the maximum data rate or service life of the drive amplifier itself.

[0018] In summary, there is still a need for an improved amplifier device to more effectively amplify signals with a DC signal component. SUMMARY OF THE INVENTION

[0019] An object of the present invention is to provide an amplifier device that solves the deficiencies of the prior art. For example, an object is to provide an amplifier device for amplifying a signal and filtering out the DC component of the signal.

[0020] The foregoing and other objects are achieved by the subject matter of the independent claims. Other embodiments are apparent from the dependent claims, the description, and the drawings.

[0021] Generally, the present invention relates to an integrated drive amplifier device for amplifying a signal and filtering out the DC component of the signal. Embodiments of the present invention allow the low cut-off frequency of a drive amplifier integrated with an AC coupling component to be extended without reducing the high cut-off frequency or reliability margin of the drive amplifier itself.

[0022] More specifically, according to a first aspect, the present invention relates to an amplification device for amplifying a signal, wherein the signal has a DC component. The amplification device includes: a coupling and filtering circuit having an input terminal for receiving an input signal and an output terminal for outputting a filtered output signal, wherein the coupling and filtering circuit is configured to at least attenuate the DC signal component of the input signal to obtain the filtered output signal. The coupling and filtering circuit includes: a first capacitor circuit connecting the input terminal to the output terminal, the first capacitor circuit including a first capacitor; a second capacitor circuit connected in parallel with the first capacitor circuit, the second capacitor circuit including a second capacitor, a first resistor, and a second resistor, the second capacitor, the first resistor, and the second resistor being connected in series. The coupling and filtering circuit further includes a resistor circuit connected to the input terminal and the output terminal, the resistor circuit including a third resistor connected to the input terminal and a fourth resistor connected to the output terminal. The amplification device further includes an amplification circuit connected to the output terminal for amplifying the filtered signal to obtain an amplified filtered signal.

[0023] Therefore, an improved amplification device is provided that allows a signal to be amplified and the DC component of the signal to be filtered out.

[0024] In another possible implementation of the first aspect, the second capacitor circuit is connected in parallel with the first capacitor of the first capacitor circuit.

[0025] In another possible implementation of the first aspect, the first capacitor circuit consists only of the first capacitor.

[0026] In another possible implementation of the first aspect, the second capacitor is connected between the first resistor and the second resistor, the first resistor is directly connected to the input terminal, and the second resistor is directly connected to the output terminal.

[0027] Therefore, the low cut-off frequency of the amplifying device is reduced without affecting the high cut-off frequency.

[0028] In another possible implementation of the first aspect, the second capacitor circuit consists only of the second capacitor, the first resistor, and the second resistor.

[0029] Therefore, the low cut-off frequency of the amplifying device is reduced without affecting the high cut-off frequency.

[0030] In another possible implementation of the first aspect, the third resistor of the resistor circuit is arranged to couple the input terminal to a reference potential, in particular the ground potential, and / or the fourth resistor of the resistor circuit is arranged to couple the output terminal to a reference potential, in particular the ground potential.

[0031] Therefore, the input terminal and / or the output terminal can be connected to the reference potential respectively.

[0032] In another possible implementation of the first aspect, the amplifying circuit includes or consists of a field effect transistor, and the field effect transistor has a gate terminal, wherein the output terminal is connected to the above-mentioned gate terminal.

[0033] Therefore, the filtered digital signal output from the output terminal can be amplified.

[0034] In another possible implementation of the first aspect, the amplifying device further includes another coupling filter circuit, the composition of the other coupling circuit is the same as that of the above-mentioned coupling filter circuit, and the above-mentioned coupling filter circuit and the other coupling filter circuit are arranged for differential mode operation.

[0035] Therefore, the coupling filter can be used in applications based on differential signals.

[0036] In another possible implementation of the first aspect, the amplifying device further includes another amplifying circuit, in particular another field effect transistor, and the other amplifying circuit is arranged downstream of the above-mentioned other coupling filter circuit.

[0037] Therefore, the filtered digital signal provided by the other coupling filter circuit can also be amplified.

[0038] In another possible implementation of the first aspect, the other coupling filter circuit includes another input terminal for receiving an inverted version of the above-mentioned input signal and another output terminal for outputting another filtered output signal.

[0039] The other coupling filter circuit includes: another first capacitor circuit connecting another input terminal to another output terminal, the another first capacitor circuit including another first capacitor; another second capacitor circuit connected in parallel to the another first capacitor circuit, the another second capacitor circuit including another second capacitor, another first resistor, and another second resistor, the another second capacitor, the another first resistor, and the another second resistor being connected in series; another resistor circuit connected to the another input terminal and the another output terminal, the another resistor circuit including another third resistor connected to the another input terminal and another fourth resistor connected to the another output terminal.

[0040] The third resistor of the resistor circuit is electrically connected to the another third resistor of the another resistor circuit, thereby connecting the coupling filter circuit to the another coupling filter circuit.

[0041] In another possible implementation of the first aspect, the third resistor and the another third resistor are electrically connected at a connection point, wherein the amplification device includes a shunt capacitor that connects the connection point to a reference potential, particularly a ground potential.

[0042] Therefore, the shunt capacitor of the amplification device can shunt high-frequency common mode.

[0043] In another possible implementation of the first aspect, the amplification device further includes a diode circuit including a first diode and a second diode, the first diode and the second diode being connected in anti-parallel to each other, and the anti-parallel diode circuit connecting the connection point to a reference potential, particularly a ground potential.

[0044] Therefore, the shunt capacitor can be protected from electrostatic discharge.

[0045] In another possible implementation of the first aspect, each input terminal is connected to a reference potential, particularly a ground potential, via a shunt resistor.

[0046] In another possible implementation of the first aspect, each coupling filter circuit has an electrical band-pass characteristic, particularly having a low cut-off frequency equal to 300 kHz within a tolerance range, the tolerance range being particularly + / - 5% or + / - 10%.

[0047] Therefore, each coupling filter circuit complies with the IEEE 802.3bs standard.

[0048] In another possible implementation of the first aspect, each coupling filter circuit includes an integrated capacitor according to metal-insulator-metal technology.

[0049] According to a second aspect, the present invention relates to an optical receiver, the optical receiver including the amplification device of the first aspect, wherein the optical receiver includes a converter for converting an optical signal into an electrical signal.

[0050] Accordingly, an improved optical receiver is provided that allows for more efficient conversion of optical signals into electrical signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Other embodiments of the present invention will be described with reference to the drawings, in which:

[0052] Figure 1 A schematic diagram of an existing integrated AC-coupled driver amplifier scheme is shown;

[0053] Figure 2 A schematic diagram of an existing integrated AC-coupled driver amplifier scheme based on metal-insulator-metal is shown;

[0054] Figure 3 A schematic diagram of an amplification device according to an embodiment is shown;

[0055] Figure 4 A schematic diagram of an integrated AC-coupled driver amplifier according to an embodiment is shown;

[0056] Figure 5 A schematic diagram of an amplification device according to an embodiment is shown;

[0057] Figure 6 A schematic diagram of an amplification device according to an embodiment is shown;

[0058] Figure 7 A schematic diagram of an integrated AC-coupled driver amplifier in differential mode according to an embodiment is shown;

[0059] Figure 8 A schematic diagram of an integrated AC-coupled driver amplifier including a shunt capacitor in differential mode according to an embodiment is shown;

[0060] Figure 9 A schematic diagram of an integrated AC-coupled driver amplifier including a diode circuit in differential mode according to an embodiment is shown.

[0061] In the respective drawings, the same reference numerals will be used for the same or at least functionally equivalent features. DETAILED DESCRIPTION

[0062] In the following description, reference is made to the drawings, which form a part of the present disclosure and in which specific aspects of the present invention are shown by way of illustration. It should be understood that other aspects may be utilized and structural or logical changes may be made without departing from the scope of the present invention. Accordingly, the following detailed description should not be taken in a limiting sense, as the scope of the present invention is defined by the appended claims.

[0063] For example, it should be understood that the disclosures related to the described methods are also applicable to corresponding devices or systems configured to perform the methods, and vice versa. For example, if specific method steps are described, the corresponding device may include units for performing the described method steps, even if the units are not explicitly described or illustrated in the figures.

[0064] In addition, embodiments having different functional blocks or processing units that are interconnected or exchange signals are described in the following detailed description and claims. It should be understood that the present invention also encompasses embodiments that include additional functional blocks or processing units arranged between the functional blocks or processing units of the following embodiments.

[0065] Finally, it should be understood that the features of the various exemplary aspects described herein can be combined with each other unless otherwise specifically stated.

[0066] As will be described in more detail below with reference to Figure 3 and Figure 4 Embodiments of the present invention relate to an amplification device 300 for amplifying a signal having a DC component to be filtered out.

[0067] From Figure 3 It can be seen that the amplification device 300 includes: a coupling filter circuit 301 having an input terminal 315 for receiving an input signal and an output terminal 317 for outputting a filtered output signal, wherein the coupling filter circuit 301 is configured to at least attenuate the DC signal component of the input signal to obtain a filtered output signal.

[0068] According to an embodiment, the coupling filter circuit 301 includes a first capacitor circuit and a second capacitor circuit. The first capacitor circuit connects the input terminal 315 to the output terminal 317, and the first capacitor circuit includes a first capacitor 303; the second capacitor circuit is connected in parallel with the first capacitor circuit, and the second capacitor circuit includes a second capacitor 305, a first resistor 307, and a second resistor 309, wherein the second capacitor 305, the first resistor 307, and the second resistor 309 are connected in series.

[0069] According to an embodiment, the coupling filter circuit 301 further includes: a resistor circuit connected to the input terminal 315 and the output terminal 317, and the resistor circuit includes a third resistor 311 connected to the input terminal 315 and a fourth resistor 313 connected to the output terminal 317.

[0070] The amplification device 300 further includes an amplification circuit 321 connected to the output terminal 317, wherein the amplification circuit 321 is configured to amplify the filtered signal to obtain an amplified filtered signal.

[0071] Figure 4Shows a more general schematic diagram of an integrated coupling filter circuit 301 according to an embodiment, where the coupling filter circuit 301 mainly includes the following components: two capacitors (C G1 303 and C G2 305); four resistors (R1 311, R2 309, R3 307 and R G 313); an input port 315 (IN) and an output port 317 (OUT).

[0072] As Figure 3 and Figure 4 shown, the second capacitor circuit is connected in parallel with the first capacitor 303 of the first capacitor circuit, and the first capacitor circuit consists only of the first capacitor 303. Similarly, the second capacitor circuit consists only of the second capacitor 305, the first resistor 307 and the second resistor 309. The second capacitor 305 is connected between the first resistor 307 and the second resistor 309, the first resistor 307 is directly connected to the input terminal 315, and the second resistor 309 is directly connected to the output terminal 317.

[0073] According to an embodiment, the third resistor 311 of the resistor circuit is arranged to couple the input terminal 315 to a reference potential, particularly the ground potential, and / or the fourth resistor 313 of the resistor circuit is arranged to couple the output terminal 317 to a reference potential, particularly the ground potential. Additionally, the amplifier circuit includes or is formed by a field effect transistor having a gate terminal, where the output terminal is connected to the gate terminal.

[0074] According to an embodiment of the present invention, by appropriately selecting the values of the second capacitor C G2 305, the first resistor R3 307 and the second resistor R2 309, the low cut-off frequency of the drive amplifier can be extended without reducing the maximum data rate or lifespan of the drive amplifier itself. To highlight the advantages, it is convenient to analyze the drive amplifier according to an embodiment in the low-frequency range and the high-frequency range, which will be described below with reference to Figure 5 and Figure 6 .

[0075] In the low-frequency range, the equivalent impedance of the second capacitor C G2 305 is much higher than that of the first resistor R3 307 and the second resistor R2 309. Therefore, Figure 3 the proposed amplification device shown can be simplified to Figure 5 the amplification device 500 shown, where the amplification device 500 includes a coupling filter circuit 501 and an amplifier circuit 503. Figure 5 The low cut-off frequency (ω LCF ) obtained by the amplification device 500 in

[0076]

[0077] Therefore, assuming that the first capacitor C G 1 303 is equal to Figure 1 the capacitor C in G , by increasing the value of the resistor R G , the low cut-off frequency (ω LCF ) of the proposed amplifier is reduced, i.e., extended, without affecting the reliability margin of the driving amplifier.

[0078] In the high-frequency range, according to the embodiment, the equivalent impedance of the first capacitor C G1 303 and the second capacitor C G2 305 is much higher than that of the first resistor R3 307 and the second resistor R2 309. Therefore, Figure 3 the embodiment shown can be simplified to Figure 6 the amplification device 600 shown, where the amplification device 600 includes a coupling filter circuit 601 and an amplification circuit 603. Figure 6 The high cut-off frequency (ω HCF ) obtained by the amplification device 600 in

[0079]

[0080] where C B1 represents the parasitic capacitance 605 of the first capacitor C G1 303 to the ground. According to the above formula, noting that the parasitic capacitance (C G2 ) of the second capacitor C B2 305 to the ground does not affect the high cut-off frequency of the amplification device 600.

[0081] To further demonstrate the benefits of the amplification device according to the embodiments of the present invention, numerical examples will be discussed below.

[0082] Assume that the driving amplifier is designed to achieve a low cut-off frequency of 1 MHz and a high cut-off frequency of 45 GHz. The resulting values of the capacitors and resistors in the prior art driving amplifier are as follows: R s , R1, R G are 50 Ohm, 50 Ohm, 50 KOhm respectively; C G , C B , C GS are 3.2 pF, 32 fF, 110 fF respectively, where it is assumed that the parasitic capacitance (C B ) of the MIM capacitor to the ground is 100 times lower than the MIM capacitor value (C G ). In addition, it is assumed that the input capacitance of the amplifier module is 110 fF. Finally, it is assumed that the output impedance (R s ) of the power supply is 50 Ohm.

[0083] By using the above formula in the background section, it can be deduced that the low cut-off frequency is 1 MHz and the high cut-off frequency is 45 GHz. Now it is required to extend the low cut-off frequency of the drive amplifier to 300 KHz to meet the new standard without affecting the reliability margin of the drive amplifier.

[0084] By using the prior art solution, the only way is to increase the value of the MIM capacitor (i.e., CG = 10.6 pF), where R s , R1, R G are 50 ohms, 50 ohms, and 50 k ohms respectively; C G , C B , C GS are 10.6 pF, 106 fF, and 110 fF respectively.

[0085] However, the parasitic capacitance to ground (C B ) will also increase, causing the high cut-off frequency to decrease to 29.5 GHz.

[0086] Conversely, for the embodiment of the present invention, the low cut-off frequency can be extended without affecting the high cut-off frequency. In fact, appropriate values of the second capacitor C G2 , the first resistor R3 307, and the second resistor R2 309 can be selected as follows: R s , R1, R G are 50 Ohm, 50 Ohm, and 50 KOhm respectively; C G , C B , C GS are 3.2 pF, 32 fF, and 110 fF respectively; R2, R3, C G2 , C B2 are 3 KOhm, 3 KOhm, 7.4 pF, and 74 fF respectively.

[0087] By using the above equations discussed in conjunction with Figure 5 and Figure 6 , it can be found that the low cut-off frequency of the amplification device is extended to 300 KHz while the high cut-off frequency remains the same, i.e., equal to 45 GHz.

[0088] According to another embodiment, Figure 7 shows a schematic diagram of an exemplary amplification device 700, which can be used for differential mode. As can be observed closely from Figure 7 , the amplification device 700 further includes a coupling filter circuit 301 and another coupling filter circuit 701, where the composition of the other coupling circuit 701 is the same as that of the coupling filter circuit 301, and the coupling filter circuit 301 and the other coupling filter circuit 701 are arranged for differential mode operation.

[0089] In an embodiment, the amplification device 700 further includes another amplification circuit, particularly another field effect transistor, disposed downstream of another coupling filter circuit 701.

[0090] As Figure 3 and Figure 4 shown, the coupling filter circuit 301 includes: a first capacitor circuit connecting an input terminal 315 to an output terminal 317, the first capacitor circuit including a first capacitor 303; a second capacitor circuit connected in parallel with the first capacitor circuit, the second capacitor circuit including a second capacitor 305, a first resistor 307, and a second resistor 309, wherein the second capacitor 305, the first resistor 307, and the second resistor 309 are connected in series. According to an embodiment, the coupling filter circuit 301 further includes: a resistor circuit connected to the input terminal 315 and the output terminal 317, the resistor circuit including a third resistor 311 connected to the input terminal 315 and a fourth resistor 313 connected to the output terminal 317.

[0091] In another embodiment, another coupling filter circuit 701 includes another input terminal 715 for receiving an inverted version of an input signal and another output terminal 717 for outputting another filtered output signal.

[0092] Another coupling filter circuit 701 includes: another first capacitor circuit connecting another input terminal 715 to another output terminal 717, the another first capacitor circuit including another first capacitor 703; another second capacitor circuit connected in parallel with the another first capacitor circuit, wherein the another second capacitor circuit includes another second capacitor 705, another first resistor 707, and another second resistor 709. The another second capacitor 705, the another first resistor 707, and the another second resistor 709 are connected in series.

[0093] In an embodiment, another coupling filter circuit 701 further includes: another resistor circuit connected to another input terminal 715 and another output terminal 717, the another resistor circuit including another third resistor 711 connected to another input terminal 715 and another fourth resistor 713 connected to another output terminal 717.

[0094] As Figure 7 shown, the third resistor 311 of the resistor circuit and the third resistor 711 of another resistor circuit are electrically connected, thereby connecting the coupling filter circuit 301 to another coupling filter circuit 701.

[0095] Figure 8 A schematic diagram of an exemplary amplification device 800 according to an embodiment is shown, wherein a capacitor (C1) is added to the amplification device 700 as Figure 7 shown to shunt high-frequency common mode. Similar to Figure 7The amplification device 700 therein, the amplification device 800 includes a coupling filter circuit 301 and another coupling filter circuit 701, wherein the constitution of the other coupling circuit 701 is the same as that of the coupling filter circuit 301.

[0096] In particular, the third resistor 311 and another third resistor 711 are electrically connected at the connection point, wherein the amplification device 800 includes a shunt capacitor 801 that connects the connection point to a reference potential, in particular the ground potential.

[0097] Figure 9 A schematic diagram of an exemplary amplification device 900 according to an embodiment is shown, wherein two diodes, namely a first diode 901 and a second diode 903, are added to the amplification device 800 as Figure 8 shown to protect the shunt capacitor 801 from electrostatic discharge.

[0098] Similar to Figure 7 the amplification device 700 therein or Figure 8 the amplification device 800 therein, the amplification device 900 also includes a coupling filter circuit 301 and another coupling filter circuit 701, wherein the constitution of the other coupling circuit 701 is the same as that of the coupling filter circuit 301.

[0099] In an embodiment, the amplification device 900 includes a diode circuit, the diode circuit includes a first diode 901 and a second diode 903, wherein the first diode 901 and the second diode 903 are anti-parallel to each other, and the anti-parallel diode circuit connects the connection point to a reference potential, in particular the ground potential.

[0100] In an embodiment, each input terminal is connected to a reference potential, in particular the ground potential, via a shunt resistor.

[0101] In an embodiment, each coupling filter circuit has an electrical band-pass characteristic, in particular having a low cut-off frequency equal to 300 kHz, and the cut-off frequency has a certain tolerance range, in particular + / - 5% or + / - 10%.

[0102] Although specific features or aspects of the present disclosure may be disclosed only in connection with some of the several embodiments or examples, such features or aspects may be combined with one or more other features or aspects of other embodiments or examples as needed or beneficial for any given or particular application. Further, to the extent that the terms "comprising," "having," "include," or other variants thereof are used in the detailed description or the claims, these terms are intended to be inclusive in a manner similar to the term "including." Further, the terms "exemplary," "for example," and "such as" are provided only as examples, and not as the best or optimal. The terms "coupled" and "connected" and derivatives thereof may have been used. It should be understood that these terms may have been used to indicate that two elements cooperate or interact with each other, whether or not they are in direct physical or electrical contact, or not in direct contact with each other.

[0103] Although specific aspects have been illustrated and described herein, those of ordinary skill in the art will appreciate that various alternative and / or equivalent implementations may be substituted for the specific aspects shown and described without departing from the scope of the present invention. This application is intended to cover any modifications or variations of the specific aspects discussed herein.

[0104] Although the elements in the following claims are recited in a particular order with corresponding reference numerals, these elements are not necessarily intended to be implemented in that particular order unless the claim recitation otherwise implies a specific order for implementing some or all of these elements.

[0105] In view of the foregoing teachings, many alternatives, modifications, and variations will be apparent to those of skill in the art. Of course, those of skill in the art will readily recognize that many applications of the present invention extend beyond those described herein. Although the present invention has been described with reference to one or more specific embodiments, those of skill in the art recognize that many changes may be made thereto without departing from the scope of the present invention. Accordingly, it should be understood that within the scope of the appended claims and their equivalents, the present invention may be practiced in a manner different from that specifically described herein.

Claims

1. An amplification device (300) for amplifying a signal, the amplification device (300) comprising: A coupling filter circuit (301) having an input terminal (315) for receiving an input signal, an output terminal (317) for outputting a filtered output signal, and an electrical band-pass characteristic having a low cut-off frequency equal to 300 kHz within a tolerance range, the tolerance range being + / - 5% or + / - 10%, wherein the coupling filter circuit (301) is configured to at least attenuate the DC signal component of the input signal to obtain the filtered output signal, wherein the coupling filter circuit (301) includes - A first capacitor circuit connecting the input terminal (315) to the output terminal (317), the first capacitor circuit including a first capacitor (303); - A second capacitor circuit connected in parallel with the first capacitor circuit, the second capacitor circuit including a second capacitor (305), a first resistor (307), and a second resistor (309), the second capacitor (305), the first resistor (307), and the second resistor (309) being connected in series; and - A resistor circuit connected to the input terminal (315) and the output terminal (317), the resistor circuit including a third resistor (311) connected to the input terminal (315) and a fourth resistor (313) connected to the output terminal (317); and An amplification circuit (321) connected to the output terminal (317), the amplification circuit (321) being configured to amplify the filtered signal to obtain an amplified filtered signal.

2. The amplification device (300) according to claim 1, wherein, The second capacitor circuit is connected in parallel to the first capacitor (303) of the first capacitor circuit.

3. The magnifying device (300) according to claim 1, wherein, The first capacitor circuit consists only of the first capacitor (303).

4. The magnifying device (300) according to claim 1, wherein, The second capacitor (305) is connected between the first resistor (307) and the second resistor (309), the first resistor (307) being directly connected to the input terminal (315), and the second resistor (309) being directly connected to the output terminal (317).

5. The magnifying device (300) according to claim 1, wherein, The second capacitor circuit consists only of the second capacitor (305), the first resistor (307), and the second resistor (309).

6. The magnifying device (300) according to claim 1, wherein, The third resistor (311) of the resistor circuit is arranged to couple the input terminal (315) to a reference potential, the reference potential being a ground potential, and / or wherein the fourth resistor (313) of the resistor circuit is arranged to couple the output terminal (317) to a reference potential, the reference potential being a ground potential.

7. The amplifying device (300) according to claim 1, wherein, The amplification circuit (321) includes or is constituted by a field effect transistor having a gate terminal, wherein the output terminal (317) is connected to the gate terminal.

8. The amplification device (300) according to claim 1, further comprising another coupling filter circuit (701), the constitution of the another coupling filter circuit (701) being the same as that of the coupling filter circuit (301), the coupling filter circuit (301) and the another coupling filter circuit (701) being arranged for differential mode operation.

9. The amplification device (300) according to claim 8, comprising another amplification circuit, the another amplification circuit being another field effect transistor, the another amplification circuit being arranged downstream of the another coupling and filtering circuit (701).

10. The magnifying device (300) according to claim 8, wherein, The another coupling and filtering circuit (701) comprises another input terminal (715) for receiving an inverted version of the input signal, another output terminal (717) for outputting another filtered output signal, and: - another first capacitor circuit connecting the another input terminal (715) to the another output terminal (717), the another first capacitor circuit comprising another first capacitor (703); - another second capacitor circuit connected in parallel to the another first capacitor circuit, the another second capacitor circuit comprising another second capacitor (705), another first resistor (707), and another second resistor (709), the another second capacitor (705), the another first resistor (707), and the another second resistor (709) being connected in series; and - another resistor circuit connected to the another input terminal (715) and the another output terminal (717), the another resistor circuit comprising another third resistor (711) connected to the another input terminal (715) and another fourth resistor (713) connected to the another output terminal (717), wherein the third resistor (311) of the resistor circuit is electrically connected to the another third resistor (711) of the another resistor circuit, thereby connecting the coupling and filtering circuit (301) to the another coupling and filtering circuit (701).

11. The magnifying device (300) according to claim 10, wherein, The third resistor (311) and the another third resistor (711) are electrically connected at a connection point, wherein the amplification device (300) comprises a shunt capacitor (801), the shunt capacitor (801) connecting the connection point to a reference potential, the reference potential being a ground potential.

12. The amplification device (300) according to claim 11, further comprising a diode circuit, the diode circuit comprising a first diode (901) and a second diode (903), the first diode (901) and the second diode (903) being anti-parallel connected to each other, the anti-parallel diode circuit connecting the connection point to a reference potential, the reference potential being a ground potential.

13. The magnifying device (300) according to claim 10, wherein, Each of the input terminals (315, 715) is connected to a reference potential, the reference potential being a ground potential, via a shunt resistor.

14. The magnifying device (300) according to any one of claims 8 to 13, wherein, Each of the coupling and filtering circuits (301, 701) comprises an integrated capacitor according to a metal-insulator-metal technology.

15. An optical receiver, comprising an amplifying device (300) according to any one of claims 1 to 14, wherein, The optical receiver comprises a converter for converting an optical signal into an electrical signal.

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