Traveling wave amplifier and information transceiver equipment

Abstract

A traveling wave amplifier has an input port and an output port, comprising: an input transmission line having a first electrostatic protection circuit; an output transmission line having a second electrostatic protection circuit; and at least two amplifiers connected between the input and output transmission lines. The equivalent capacitance and inductance of each electrostatic protection circuit match the capacitance and inductance of each amplifier's equivalent transmission line. Thus, after the electrostatic protection circuit is added, its components, as part of the traveling wave amplifier, are also incorporated into the input and output transmission lines without affecting their original electrical characteristics. By selecting appropriate component parameters, the electrostatic protection circuit does not affect the overall bandwidth of the traveling wave amplifier and increases the electrostatic discharge voltage range that the traveling wave amplifier can withstand by several times.

Description

Technical Field

[0001] The present application belongs to the technical field of amplifiers, and in particular relates to a traveling wave amplifier and an information transceiver device. Background Art

[0002] Among traditional broadband amplifier technologies, traveling-wave amplifiers (TWAs), also known as distributed amplifiers, are the most widely used broadband amplification technology. TWAs can achieve high, flat gain across a wide frequency band and are widely used in high-speed communications, microwave and millimeter-wave wireless communications, broadband wireless transceivers, high-resolution radar, and imaging systems. For example, in the high-speed optical communications industry, very high-bandwidth broadband amplifiers are essential for 100 / 200 / 400 Gbit / s optical communication systems. Therefore, traveling-wave amplifiers (TWAs) using high-electron mobility transistors (HEMTs) are often used as modulator drivers due to their very wide bandwidth and high breakdown voltage.

[0003] A traveling-wave amplifier (TWA) is a broadband amplifier circuit in which the input and output equivalent capacitances of transistors are equated to transmission lines, forming an LC (inductor-capacitor) ladder network. The input / output equivalent capacitances of the active devices and the on-chip spiral inductor form the amplifier's gate and drain lines, respectively. These lines are lumped-parameter low-pass transmission lines with different characteristic impedances. The input signal is transmitted on the gate line and applied to the gate of the active device at different phases. Transconductance generates an amplified signal on the drain line. When the signal is transmitted in phase on the gate and drain lines of each amplifier stage, the amplified signal on the drain line is superimposed in phase, achieving broadband amplification.

[0004] Due to the characteristics of the traveling wave amplifier described above, if a traditional ESD (Electro-Static discharge) protection circuit is added to the input and output ends of the traveling wave amplifier, the bandwidth of the traveling wave amplifier will be severely reduced. Therefore, the input and output ends of the traditional traveling wave amplifier cannot be protected by the traditional ESD protection circuit, resulting in poor electrostatic withstand voltage protection capability and low reliability of the traditional traveling wave amplifier. Summary of the Invention

[0005] In view of this, embodiments of the present application provide a traveling wave amplifier and an information transceiver device, aiming to solve the problems of poor electrostatic withstand voltage protection capability and low reliability of traditional traveling wave amplifiers.

[0006] A first aspect of an embodiment of the present application provides a traveling wave amplifier having an input port and an output port, wherein the traveling wave amplifier circuit includes:

[0007] an input transmission line connected to the input port and comprising a first electrostatic protection circuit and a plurality of first inductive elements connected in series, wherein the first electrostatic protection circuit is close to the input port;

[0008] an output transmission line connected to the output port and comprising a second electrostatic protection circuit and a plurality of second inductive elements connected in series, wherein the second electrostatic protection circuit is close to the output port; and

[0009] at least two amplifiers connected between the input transmission line and the output transmission line;

[0010] Among them, the capacitance and inductance of the first electrostatic protection circuit equivalent to the input transmission line are matched with the input capacitance and inductance of each amplifier equivalent to the input transmission line, and the capacitance and inductance of the second electrostatic protection circuit equivalent to the output transmission line are matched with the output capacitance and inductance of each amplifier equivalent to the output transmission line.

[0011] In one embodiment, the equivalent capacitance value and the equivalent inductance value of the first electrostatic protection circuit to the input transmission line are respectively consistent with the equivalent capacitance value and the equivalent inductance value of each amplifier to the input transmission line.

[0012] In one embodiment, the equivalent capacitance value and the equivalent inductance value of the second electrostatic protection circuit to the output transmission line are respectively consistent with the equivalent capacitance value and the equivalent inductance value of each amplifier to the output transmission line.

[0013] In one embodiment, each of the amplifiers includes a transistor device having a gate connected to the input transmission line and a drain connected to the output transmission line.

[0014] In one embodiment, each of the transistor devices comprises one or more transistors cascade-connected between a common terminal, an input transmission line, and an output transmission line.

[0015] In one embodiment, an input connection point is formed between adjacent first inductive elements on the input transmission line, an output connection point is formed between adjacent second inductive elements on the output transmission line, the first electrostatic protection circuit is connected to the first input connection point close to the input port side, the second electrostatic protection circuit is connected to the first output connection point close to the output port side, and each of the amplifiers is connected in sequence between the input connection point other than the first input connection point and the output connection point other than the first output connection point.

[0016] In one embodiment, the first electrostatic protection circuit includes a first diode and a second diode; the cathode of the first diode is connected to the power supply, and the anode is connected to the first input connection point; the cathode of the second diode is connected to the first input connection point, and the anode is connected to the negative power supply or ground.

[0017] In one embodiment, the second electrostatic protection circuit includes a third diode and a fourth diode; the cathode of the third diode is connected to the power supply, and the anode is connected to the first output connection point; the cathode of the fourth diode is connected to the first output connection point, and the anode is connected to the negative power supply or ground.

[0018] In one embodiment, the system further includes a plurality of matching capacitors connected between the output transmission line and a common terminal.

[0019] In one embodiment, the capacitance of the matching capacitor is selected according to the difference between the equivalent capacitance of the input transmission line and the equivalent capacitance of the output transmission line.

[0020] In one embodiment, the capacitance of the matching capacitor is equal to the difference between the capacitance of the equivalent capacitance of the input transmission line and the capacitance of the equivalent capacitance of the output transmission line.

[0021] A second aspect of an embodiment of the present application provides an information transceiver device, including the traveling wave amplifier described above.

[0022] The electrostatic protection circuit of the above-mentioned traveling wave amplifier is placed in the transmission lines at the input and output ends. In order to ensure the bandwidth of the traveling wave amplifier, after the electrostatic protection circuit is added, the components of the electrostatic protection circuit are added to the input transmission line and the output transmission line as part of the traveling wave amplifier. The electrostatic protection circuit can select parameters based on the equivalent capacitance and equivalent inductance of the amplifier in the input / output transmission line, so that it still needs to meet the bandwidth and characteristic impedance corresponding to the cutoff frequency of the traveling wave amplifier, and does not affect the original electrical characteristics of the input transmission line and the output transmission line. In this way, the electrostatic protection circuit will not affect the total bandwidth of the traveling wave amplifier. In addition, after adding the electrostatic protection circuit, the electrostatic discharge voltage range that the traveling wave amplifier can withstand can be increased several times. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0024] Figure 1A schematic diagram of the traveling wave amplifier structure provided in an embodiment of the present application (to briefly illustrate the principle of the traveling wave amplifier, the bias circuit of the transistor is not shown);

[0025] Figure 2(A) shows Figure 1 An exemplary circuit schematic diagram of a first electrostatic protection circuit in a traveling wave amplifier is shown;

[0026] FIG2(B) is a schematic diagram of equivalent capacitance and equivalent inductance of the first electrostatic protection circuit shown in FIG2(A);

[0027] Figure 3(A) shows Figure 1 An exemplary circuit schematic diagram of a second electrostatic protection circuit in a traveling wave amplifier is shown;

[0028] FIG3(B) is a schematic diagram of equivalent capacitance and equivalent inductance of the second electrostatic protection circuit shown in FIG3(A);

[0029] Figure 4 for Figure 1 An example circuit schematic of the equivalent capacitance of the input transmission line in a traveling wave amplifier is shown. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0031] In a traveling wave amplifier, each amplifier has parasitic capacitance. The parasitic capacitance at the input and output of each amplifier, as well as the parasitic capacitance of the transmission line, can be equated to the transmission line. The inductance in each amplifier and the parasitic inductance of the transmission line are also equated to the transmission line. It can be seen that the electrical characteristics of the input transmission line are defined by the equivalent capacitance and equivalent inductance, and the electrical characteristics of the output transmission line are also defined by the equivalent capacitance and equivalent inductance. It should also be noted that the inductive elements on the transmission line of a traveling wave amplifier generally include parasitic inductance and the equivalent inductance of the amplifier equivalent to the link, and of course can also include discrete inductance devices connected in series with the link.

[0032] See also Figure 1 The traveling wave amplifier provided in the embodiments of the present application can be used in information transceiver equipment, such as high-speed communications, broadband wireless transceivers, high-resolution radar, and imaging systems. The traveling wave amplifier 10 provided in the embodiments of the present application has an input port 12 and an output port 14. The traveling wave amplifier 10 includes an input transmission line 16, an output transmission line 18, and at least two amplifiers 19.

[0033] The input transmission line 16 is connected to the input port 12 and includes a first electrostatic protection circuit 162 and a plurality of first inductive elements 164 connected in series. The first electrostatic protection circuit 162 is close to the input port 12 .

[0034] In one embodiment, the first inductive element 164 between any amplifier 19 has an inductance of L1, and the first and last first inductive elements 164 have an inductance of L1 / 2. In addition, the input port 12 is provided at one end of the input transmission line 16, and the other end of the input transmission line 16 is connected to a common terminal via a resistor Rg.

[0035] Output transmission line 18 is connected to output port 14 and includes a second electrostatic protection circuit 182 and multiple second inductive elements 184 connected in series. Second electrostatic protection circuit 182 is located near output port 14. First inductive element 164 and second inductive element 184 can be lumped inductors or transmission line equivalent inductors, and their selection depends on the operating frequency band and environment.

[0036] In one embodiment, the second inductive element 184 between any amplifiers 19 has an inductance of L2, and the first and last second inductive elements 184 have an inductance of L2 / 2. The output port 14 is provided at the output end of the output transmission line 18, and the input end of the output transmission line 18 is connected to the common terminal through the resistor Rd.

[0037] In this example, the resistance values of resistors Rd and Rg are consistent, matching the impedances of input transmission line 16 and output transmission line 18 respectively to prevent reflection along the transmission lines, and the common end is usually ground, and the inductor L1 and inductor L2 are consistent.

[0038] Amplifier 19 is connected between input transmission line 16 and output transmission line 18. In this example, amplifiers 19 are connected in parallel in the same direction. The input signal is transmitted on input transmission line 16 and applied to the input of amplifier 19 at different phases. The amplified signal is then generated on output transmission line 18 through transconductance. When the signal is transmitted in phase at the input and output of each amplifier 19 stage, the amplified signals on output transmission line 18 are superimposed in phase, thus achieving broadband amplification. In other embodiments, amplifiers 19 can also be connected in anti-parallel.

[0039] In one embodiment, the amplifier 19 includes a transistor device, the gate of the transistor device is connected to the input transmission line 16, and the drain of the transistor device is connected to the output transmission line 18. In this way, the input transmission line 16 is the gate line, and the output transmission line 18 is the drain line. Each transistor device 19 includes one or more transistors 192 cascaded between the common terminal and the output transmission line 18. In this example, each transistor device is shown as two vertically cascaded field effect transistors 192. The gate of one field effect transistor 192 is connected to the input transmission line 16, and the drain of the other field effect transistor 192 is connected to the output transmission line 18. In other embodiments, each transistor device can be set to one field effect transistor or three or more cascaded field effect transistors according to the signal amplification requirements.

[0040] See also Figure 1 2(A), 2(B), 3(A), and 3(B), the parasitic capacitance Cesd1 of the first electrostatic protection circuit 162 equivalent to the input transmission line 16 is selected to match the capacitance of each amplifier 19 equivalent to the input transmission line 16, and the parasitic capacitance Cesd2 of the second electrostatic protection circuit 182 equivalent to the output transmission line 18 is selected to match the capacitance of each amplifier 19 equivalent to the output transmission line 18. At the same time, the inductance of the first electrostatic protection circuit 162 equivalent to the input transmission line 16 (i.e., its parasitic inductance) is selected to match the inductance of each amplifier 19 equivalent to the input transmission line 16, and the inductance of the second electrostatic protection circuit 182 equivalent to the output transmission line 18 (i.e., its parasitic inductance) is selected to match the inductance of each amplifier 19 equivalent to the output transmission line 18.

[0041] Each amplifier 19 has an input (gate-source) capacitance Cin and an output (source-drain) capacitance Cout, and in the traveling wave amplifier 10, the input capacitance Cin and the output capacitance Cout of the amplifier 19 can be equivalent to the input / output transmission lines 16 and 18, that is, the LC ladder network. Figure 4 The equivalent capacitance C of the input transmission line 16 includes the input capacitance Cin of each amplifier 19 equivalent to the input transmission line 16 and the parasitic capacitance C of each first inductive element chain. L1; Similarly, the equivalent capacitance of the output transmission line 18 includes the output capacitance Cout of each amplifier 19 equivalent to the output transmission line 18 and the parasitic capacitance of each second inductive element chain. In this example, the component parameters of the first inductive element chain input transmission line and the second inductive element chain are the same, so their parasitic capacitances are also considered to be the same. In order to ensure that the electrostatic protection circuits 162 and 182 do not affect the total bandwidth of the traveling wave amplifier 10, the equivalent parasitic capacitances Cesd1 and Cesd2 and the equivalent parasitic inductance values of the two electrostatic protection circuits 162 and 182 will be matched according to the input capacitance Cin, output capacitance Cout and equivalent parasitic inductance values of the amplifier 19 in the transmission line, respectively. The characteristic impedance of the improved traveling wave amplifier 10 and cutoff frequency This is consistent with a standard traveling wave amplifier without electrostatic protection circuits 162 and 182. At the same time, the electrostatic discharge voltage range of the traveling wave amplifier 10 is increased several times. In this example, the capacitance and equivalent (parasitic) inductance of the equivalent (parasitic) capacitance Cesd1 of the first electrostatic protection circuit 162 equivalent to the input transmission line 16 are consistent with the capacitance and equivalent (parasitic) inductance of the input capacitance Cin of each amplifier 19 equivalent to the input transmission line 16. The capacitance and equivalent (parasitic) inductance of the equivalent (parasitic) capacitance Cesd2 of the second electrostatic protection circuit 182 equivalent to the output transmission line 18 are consistent with the capacitance and equivalent (parasitic) inductance of the output capacitance Cout of each amplifier 19 equivalent to the output transmission line 18.

[0042] See also Figure 1 2(A) and 3(A), adjacent first inductive elements 164 on the input transmission line 16 form an input connection point, and adjacent second inductive elements 184 on the output transmission line 18 form an output connection point. The first electrostatic protection circuit 162 is connected to the first input connection point near the input port 12, that is, the first electrostatic protection circuit 162 is connected to the input port 12 via a (first) first inductive element 164. The second electrostatic protection circuit 182 is connected to the first output connection point near the output port 14, that is, the second electrostatic protection circuit 182 is connected to the output port 14 via a (last) second inductive element 184. Each amplifier 19 is sequentially connected between an input connection point other than the first input connection point and an output connection point other than the first output connection point. In this way, the equivalent capacitance at each input connection point is consistent, and the equivalent capacitance at each output connection point is also consistent, so that the parameters of each connection point of the input transmission line 16 and the output transmission line 18 are matched consistently, so as not to affect the overall bandwidth.

[0043] In one embodiment, see Figure 2(A) and 2(B)The first electrostatic protection circuit 162 includes a first diode D1 and a second diode D2. The cathode of the first diode D1 is connected to the power supply VDD, and the anode is connected to the first input connection point. The cathode of the second diode D2 is connected to the first input connection point, and the anode is connected to the negative power supply VSS or ground. The dimensions of the first diode D1 and the second diode D2 must be carefully selected so that the total equivalent (parasitic) capacitance Cesd1 of the first diode D1 and the second diode D2 is consistent with the capacitance Cin of the input transmission line equivalent to each amplifier stage in the traveling wave amplifier 10. The inductance of the input transmission line 16 at both ends of the connection point between the first diode D1 and the second diode D2 is L1 / 2, respectively. Thus, the total equivalent inductance of the right transmission line connected in series with the original input transmission line is L1. Similarly, referring to Figures 3(A) and 3(B), the second electrostatic protection circuit 182 includes a third diode D3 and a fourth diode D4. The cathode of the third diode D3 is connected to the power supply VDD, and the anode is connected to the first output connection point. The cathode of the fourth diode D4 is connected to the first output connection point, and the anode is connected to the negative power supply VSS or ground. The dimensions of the third diode D3 and the fourth diode D4 must be carefully selected so that the total equivalent (parasitic) capacitance Cesd2 of the third diode D3 and the fourth diode D4 is consistent with the capacitance Cout of the output transmission line equivalent to each amplifier stage 19 in the traveling wave amplifier 10. The inductance equivalent to the output transmission line 18 at both ends of the connection point between the third diode D3 and the fourth diode D4 is L2 / 2. Thus, the total equivalent inductance of the left transmission line connected in series with the original output transmission line is L2. Depending on the polarity of the electrostatic protection circuits 162 and 182 applied to the circuit input, the high-voltage discharge enters the positive or negative power supply loop through the diode connected to the positive or negative electrode. In this way, the ESD protection circuits 162 and 182 will not affect the total bandwidth of the traveling wave amplifier 10 and will not be significantly reduced due to the addition of the ESD protection circuits 162 and 182. The characteristic impedance and cutoff frequency of the improved traveling wave amplifier remain consistent with those of a standard traveling wave amplifier without an ESD protection circuit.

[0044] When the traveling wave amplifier 10 is connected to the signal to be amplified, two signal waves propagate through the transmission line. These signals are represented as the "drain line wave" corresponding to the output transmission line 18 and the "gate line wave" corresponding to the input transmission line 16. For correct signal amplification, these two waves must have the same speed, a requirement that can only be met when the input capacitance Cin = output capacitance Cout and L1 = L2. In a typical traveling wave amplifier, the input capacitance Cin is different from the output capacitance Cout. Typically, the input capacitance Cin is higher than the output capacitance Cout. Therefore, the impedance matching condition set in a typical traveling wave amplifier results in a mismatch in the propagation speeds in the two transmission lines. Specifically, the speed of the drain wave is greater than the speed of the gate wave.

[0045] Thus, in another embodiment of the present application, please refer to Figure 1 , the traveling wave amplifier 10 also includes a plurality of matching capacitors Cd connected between the output transmission line 18 and the common end. The matching capacitor Cd is used to match the output capacitor Cout of the amplifier 19, so that the input capacitance Cin = matching capacitor Cd + output capacitor Cout, so that the propagation speeds of the "leakage line wave" and the "gate line wave" in the two transmission lines are matched. It can be seen that the capacitance of the matching capacitor Cd is selected according to the capacitance difference between the equivalent capacitance of the input transmission line 16 and the equivalent capacitance of the output transmission line 18, specifically, according to the capacitance difference between the input capacitance Cin and the output capacitance Cout. Specifically, the capacitance of the matching capacitor Cd is equal to the capacitance difference between the equivalent capacitance of the input transmission line 16 and the equivalent capacitance of the output transmission line 18, that is, the matching capacitor Cd = input capacitance Cin - output capacitance Cout.

[0046] In order to demonstrate the technical effect of the traveling wave amplifier 10 provided in the embodiment of the present application, a traveling wave amplifier 10 circuit chip without an electrostatic protection circuit was tested and compared with a traveling wave amplifier 10 circuit chip with an electrostatic protection circuit provided in the embodiment of the application. The protection capabilities of the two chips for electrostatic protection were tested for the human body discharge model (HBM). The test method adopted the method described in the standard ANSI / ESDA / JEDEC JS-001-2014 (Electrodischarge Sensitivity Test-Human Body Model). The test results of the traveling wave amplifier 10 circuit chip without electrostatic protection were as follows: the chip withstood an electrostatic discharge voltage range of 125V to less than 250V, while the traveling wave amplifier 10 circuit chip with an electrostatic protection circuit added by the method in the present application withstood an electrostatic discharge voltage range of 500V to less than 1000V. The test results show that the traveling wave amplifier 10 circuit chip with an electrostatic protection circuit added by the method in the present application has significantly enhanced its protection capability against electrostatic discharge.

[0047] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A traveling wave amplifier having an input port and an output port, characterized in that: The traveling wave amplifier comprises: an input transmission line connected to the input port and comprising a first electrostatic protection circuit and a plurality of first inductive elements connected in series, wherein the first electrostatic protection circuit is close to the input port; an output transmission line connected to the output port and comprising a second electrostatic protection circuit and a plurality of second inductive elements connected in series, wherein the second electrostatic protection circuit is close to the output port; and at least two amplifiers connected between the input transmission line and the output transmission line; The first electrostatic protection circuit is connected to the input port via a first inductive element, and the capacitance and inductance equivalent to the input transmission line are matched with the capacitance and inductance equivalent to the input transmission line of each amplifier, and the second electrostatic protection circuit is connected to the output port via a second inductive element, and the capacitance and inductance equivalent to the output transmission line are matched with the capacitance and inductance equivalent to the output transmission line of each amplifier, respectively. The equivalent capacitance value and the equivalent inductance value of the first electrostatic protection circuit to the input transmission line are respectively consistent with the equivalent capacitance value and the equivalent inductance value of each amplifier to the input transmission line; The equivalent capacitance value and the equivalent inductance value of the second electrostatic protection circuit to the output transmission line are respectively consistent with the equivalent capacitance value and the equivalent inductance value of each amplifier to the output transmission line.

2. The traveling wave amplifier according to claim 1, wherein Each of the amplifiers includes a transistor device having a gate connected to the input transmission line and a drain connected to the output transmission line.

3. The traveling wave amplifier according to claim 2, wherein: Each of the transistor devices includes one or more transistors cascade-connected between a common terminal, an input transmission line, and an output transmission line.

4. The traveling wave amplifier according to claim 1, wherein An input connection point is formed between adjacent first inductive elements on the input transmission line, an output connection point is formed between adjacent second inductive elements on the output transmission line, the first electrostatic protection circuit is connected to the first input connection point close to the input port side, the second electrostatic protection circuit is connected to the first output connection point close to the output port side, and each of the amplifiers is connected in sequence between the input connection point other than the first input connection point and the output connection point other than the first output connection point.

5. The traveling wave amplifier according to claim 4, wherein: The first electrostatic protection circuit includes a first diode and a second diode; the cathode of the first diode is connected to the positive power supply, and the anode is connected to the first input connection point; the cathode of the second diode is connected to the first input connection point, and the anode is connected to the negative power supply or ground; The second electrostatic protection circuit includes a third diode and a fourth diode; the cathode of the third diode is connected to the power supply, and the anode is connected to the first output connection point; the cathode of the fourth diode is connected to the first output connection point, and the anode is connected to the negative power supply or ground.

6. The traveling wave amplifier according to claim 1, wherein The system also includes a plurality of matching capacitors connected between the output transmission line and a common terminal.

7. The traveling wave amplifier according to claim 6, wherein: The capacitance of the matching capacitor is selected according to the capacitance difference between the equivalent capacitance of the input transmission line and the equivalent capacitance of the output transmission line.

8. The traveling wave amplifier according to claim 7, wherein: The capacitance of the matching capacitor is equal to the difference between the capacitance of the equivalent capacitance of the input transmission line and the capacitance of the equivalent capacitance of the output transmission line.

9. An information transceiver device, characterized in that: A traveling wave amplifier comprising the traveling wave amplifier according to any one of claims 1 to 8.

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