CN105162420B - GaAs base low-leakage current double cantilever beam switchs double grid frequency multiplier - Google Patents

本发明的GaAs基低漏电流双悬臂梁开关双栅HEMT倍频器，由GaAs衬底，增强型HEMT，以及外接的低通滤波器，压控振荡器，除法器、高频扼流圈构成。悬臂梁开关的下拉电压设计为HEMT的阈值电压，通过直流偏置控制HEMT的导通和信号的传输。两个悬臂梁均悬浮断开时，栅电压为0，无法形成沟道，HEMT截止，有利于减小栅极漏电流。两个悬臂梁均通过直流偏置下拉闭合时，偏置改变肖特基势垒宽度，二维电子气沟道浓度增大，HEMT导通，参考信号和反馈信号通过HEMT传输。漏极输出信号经低通滤波器和压控振荡器、除法器反馈循环后，得到参考信号的倍频信号。只有一个悬臂梁开关闭合时，可实现对单个信号的放大，实现多功能。

The GaAs-based low-leakage current double-cantilever switch double-gate HEMT frequency multiplier of the present invention is composed of a GaAs substrate, an enhanced HEMT, and an external low-pass filter, a voltage-controlled oscillator, a divider, and a high-frequency choke coil . The pull-down voltage of the cantilever beam switch is designed as the threshold voltage of the HEMT, and the conduction and signal transmission of the HEMT are controlled by a DC bias. When the two cantilever beams are suspended and disconnected, the gate voltage is 0, and a channel cannot be formed, and the HEMT is cut off, which is beneficial to reduce the gate leakage current. When the two cantilever beams are pulled down and closed by the DC bias, the bias changes the width of the Schottky barrier, the concentration of the two-dimensional electron gas channel increases, the HEMT is turned on, and the reference signal and the feedback signal are transmitted through the HEMT. After the drain output signal passes through the low-pass filter, the voltage-controlled oscillator and the divider feedback loop, the multiplied frequency signal of the reference signal is obtained. When only one cantilever beam switch is closed, it can realize the amplification of a single signal and realize multi-function.

砷化镓基低漏电流双悬臂梁开关双栅倍频器Gallium Arsenide Based Low Leakage Current Double Cantilever Beam Switch Double Gate Frequency Doubler

技术领域technical field

本发明提出了GaAs(砷化镓)基低漏电流双悬臂梁开关双栅HEMT(高电子迁移率晶体管)倍频器，属于微电子机械系统的技术领域。The invention provides a GaAs (gallium arsenide)-based low-leakage current double cantilever beam switch double-gate HEMT (high electron mobility transistor) frequency multiplier, which belongs to the technical field of micro-electromechanical systems.

背景技术Background technique

倍频器是将一参考信号经过功能电路的作用,产生所需的参考信号频率整数倍的频率信号。目前，倍频器广泛应用于通信、信号处理等领域。与传统电路中的HEMT结构相比，高电子迁移率晶体管HEMT有更高的电子迁移率，速度更快，效率更高也能够降低功耗等。当前，MEMS技术也推动电路向结构简单，体积变小的方向发展。A frequency multiplier is a function of passing a reference signal through a functional circuit to generate a frequency signal that is an integer multiple of the required reference signal frequency. At present, frequency multipliers are widely used in communication, signal processing and other fields. Compared with the HEMT structure in traditional circuits, the high electron mobility transistor HEMT has higher electron mobility, faster speed, higher efficiency and lower power consumption. At present, MEMS technology also promotes the development of circuits in the direction of simple structure and smaller volume.

本发明正式要结合HEMT与MEMS技术，提出一种GaAs基低漏电流双悬臂梁开关双栅HEMT倍频器。The present invention formally combines HEMT and MEMS technologies, and proposes a GaAs-based low-leakage current double-cantilever switch double-gate HEMT frequency multiplier.

发明内容Contents of the invention

技术问题:本发明的目的是提供一种GaAs基低漏电流双悬臂梁开关双栅HEMT倍频器。两个悬臂梁与下方的两个栅极一一对应。悬臂梁在电路中起开关的作用，控制HEMT的导通以及信号的传输。Technical problem: the purpose of the present invention is to provide a GaAs-based low leakage current double cantilever beam switch double gate HEMT frequency doubler. The two cantilever beams correspond to the two gates below. The cantilever beam acts as a switch in the circuit, controlling the conduction of the HEMT and the transmission of signals.

技术方案：本发明的砷化镓基低漏电流双悬臂梁开关双栅倍频器的HEMT为生长在GaAs衬底上的增强型HEMT，包括本征GaAs层，本征AlGaAs层N+AlGaAs层，源极，漏极，栅极，锚区，悬臂梁开关，下拉极板，绝缘层，通孔，引线；在GaAs衬底上有本征GaAs层，本征GaAs层上有本征AlGaAs层，本征AlGaAs层上有N+AlGaAs层，源极，漏极位于两个悬臂梁开关的两侧，源极接地，两个栅极并列设置，与两个悬臂梁开关一一对应，悬臂梁开关的一端固定在锚区上，另一端悬浮在栅极之上，下拉极板设置在悬臂梁开关末端下方，下拉极板接地，绝缘层覆盖在下拉极板上，直流偏置通过高频扼流圈和锚区作用在悬臂梁开关上，悬臂梁开关的下拉电压设计为HEMT的阈值电压；引线分别通过通孔接本征GaAs层；Technical solution: The HEMT of the gallium arsenide-based low-leakage current double-cantilever switch double-gate frequency multiplier of the present invention is an enhanced HEMT grown on a GaAs substrate, including an intrinsic GaAs layer, an intrinsic AlGaAs layer N+AlGaAs layer , source, drain, gate, anchor region, cantilever beam switch, pull-down plate, insulating layer, via hole, lead; there is an intrinsic GaAs layer on the GaAs substrate, and an intrinsic AlGaAs layer on the intrinsic GaAs layer , there is an N+AlGaAs layer on the intrinsic AlGaAs layer, the source and drain are located on both sides of the two cantilever switches, the source is grounded, and the two gates are arranged side by side, corresponding to the two cantilever switches one by one. One end of the switch is fixed on the anchor area, the other end is suspended above the grid, the pull-down plate is set under the end of the cantilever beam switch, the pull-down plate is grounded, the insulating layer is covered on the pull-down plate, and the DC bias passes through the high-frequency choke The flow circle and the anchor region act on the cantilever switch, and the pull-down voltage of the cantilever switch is designed to be the threshold voltage of HEMT; the leads are respectively connected to the intrinsic GaAs layer through through holes;

HEMT漏极输出信号有两种工作方式，一种是选择第一端口输入至低通滤波器，低通滤波器输出接入压控振荡器，压控振荡器输出通过第二端口接入除法器，除法器输出信号作为反馈通过锚区加载到一个悬臂梁开关上，构成反馈回路，参考信号通过锚区加载到另一个悬臂梁开关上，HEMT的漏极输出信号的另一种工作方式是选择第二端口直接输出放大信号。There are two working modes for the HEMT drain output signal, one is to select the first port to input to the low-pass filter, the output of the low-pass filter is connected to the voltage-controlled oscillator, and the output of the voltage-controlled oscillator is connected to the divider through the second port , the divider output signal is loaded to a cantilever beam switch through the anchor area as feedback to form a feedback loop, and the reference signal is loaded to another cantilever beam switch through the anchor area. Another working mode of the drain output signal of the HEMT is to select The second port directly outputs the amplified signal.

所述悬臂梁开关的闭合或断开通过直流偏置控制，当两个悬臂梁开关均在达到或大于下拉电压的直流偏置下实现下拉，与栅极接触，开关呈闭合状态时，在栅电压作用下，形成二维电子气沟道，HEMT导通，参考信号和反馈信号通过HEMT实现相乘，漏极输出包含两信号的相位差信息，经第一端口输入低通滤波器，低通滤波器滤除高频部分，输出包含相位差信息的直流电压，直流电压输入压控振荡器，作为控制电压调节压控振荡器的输出频率，调节频率后的信号经第三端口传输至除法器，除法器输出信号作为新的反馈信号加载到悬臂梁开关上，环路循环反馈的结果是反馈信号与参考信号的频率相等，压控振荡器的第四端口输出频率f_o为参考信号频率的N倍：N×f_ref,实现参考信号的倍频；N是自然数；The closing or opening of the cantilever beam switch is controlled by DC bias. When the two cantilever beam switches are pulled down under the DC bias reaching or greater than the pull-down voltage, they are in contact with the gate and when the switch is in a closed state, the gate Under the action of voltage, a two-dimensional electron gas channel is formed, the HEMT is turned on, the reference signal and the feedback signal are multiplied by the HEMT, and the drain output contains the phase difference information of the two signals, which is input to the low-pass filter through the first port, and the low-pass The filter filters out the high-frequency part, outputs a DC voltage containing phase difference information, and the DC voltage is input to the voltage-controlled oscillator, which is used as a control voltage to adjust the output frequency of the voltage-controlled oscillator, and the adjusted frequency signal is transmitted to the divider through the third port , the output signal of the divider is loaded on the cantilever beam switch as a new feedback signal, the result of the loop loop feedback is that the frequency of the feedback signal is equal to the reference signal, and the output frequency f _o of the fourth port of the voltage-controlled oscillator is the frequency of the reference signal N times: N×f _ref , realizing the frequency multiplication of the reference signal; N is a natural number;

当直流偏置小于下拉电压，两个悬臂梁开关均不与栅极接触，开关断开时，栅电压为0，HEMT截止，能够有效的减小栅极漏电流，降低功耗；When the DC bias is less than the pull-down voltage, neither of the two cantilever beam switches is in contact with the gate. When the switch is turned off, the gate voltage is 0, and the HEMT is cut off, which can effectively reduce the gate leakage current and power consumption;

当只有一个悬臂梁开关闭合，另一个悬臂梁开关处于断开状态时，闭合的悬臂梁开关下方形成二维电子气沟道，断开的悬臂梁开关下方形成高阻区，沟道与高阻区串联的结构有利于提高HEMT的反向击穿电压，只有闭合的悬臂梁开关上的选通信号能通过HEMT放大，放大信号选择第二端口输出，当只有加载参考信号的悬臂梁开关闭合时，参考信号通过HEMT放大，第二端口输出参考频率f_ref的放大信号，当只有加载反馈信号的悬臂梁开关下拉时，反馈信号通过HEMT放大，反馈信号频率为压控振荡器输出频率f_o经除法器后除以N的结果：f_o/N，第二端口输出频率为f_o/N的放大信号，断开状态的悬臂梁开关有利于减小栅极漏电流，降低功耗。When only one cantilever beam switch is closed and the other cantilever beam switch is in an open state, a two-dimensional electron gas channel is formed under the closed cantilever beam switch, and a high-resistance region is formed under the disconnected cantilever beam switch. The structure in series is beneficial to improve the reverse breakdown voltage of HEMT. Only the strobe signal on the closed cantilever beam switch can be amplified by HEMT, and the amplified signal selects the second port for output. When only the cantilever beam switch loaded with the reference signal is closed , the reference signal is amplified by the HEMT, and the second port outputs the amplified signal of the reference frequency f _ref , when only the cantilever beam switch that loads the feedback signal is pulled down, the feedback signal is amplified by the HEMT, and the frequency of the feedback signal is the output frequency f _o of the voltage controlled oscillator by The result of dividing by N after the divider: f _o /N, the second port outputs an amplified signal with a frequency of f _o /N, and the off-state cantilever switch is beneficial to reduce gate leakage current and power consumption.

有益效果：本发明的GaAs基低漏电流双悬臂梁开关双栅HEMT倍频器具有以下显著的优点：Beneficial effects: the GaAs-based low-leakage current double-cantilever switch double-gate HEMT frequency multiplier of the present invention has the following significant advantages:

1、悬臂梁在电路中起到开关的作用，方便控制HEMT的导通与信号的传输；1. The cantilever beam acts as a switch in the circuit, which is convenient for controlling the conduction of the HEMT and the transmission of signals;

2、通过对悬臂梁开关的控制，不仅可以实现参考信号的倍频，还可以实现对单个信号的放大，使电路多功能化，扩展应用范围；2. Through the control of the cantilever beam switch, not only the frequency multiplication of the reference signal can be realized, but also the amplification of a single signal can be realized, which makes the circuit multi-functional and expands the application range;

3、HEMT与MEMS技术相结合，使得电路效率提升，功耗降低，结构简单化，体积小型化。3. The combination of HEMT and MEMS technology improves circuit efficiency, reduces power consumption, simplifies structure, and miniaturizes volume.

附图说明Description of drawings

图1为本发明的GaAs基低漏电流双悬臂梁开关双栅HEMT倍频器的俯视图.1 is a top view of the GaAs-based low-leakage current double-cantilever switch double-gate HEMT frequency doubler of the present invention.

图2为图1GaAs基低漏电流双悬臂梁开关双栅HEMT倍频器的A-A’向剖面图。Fig. 2 is an A-A' cross-sectional view of the GaAs-based low-leakage current double-cantilever switch double-gate HEMT frequency doubler in Fig. 1 .

图3为图1GaAs基低漏电流双悬臂梁开关双栅HEMT倍频器的B-B’向剖面图。Fig. 3 is a B-B' cross-sectional view of the GaAs-based low-leakage current double-cantilever switch double-gate HEMT frequency doubler in Fig. 1 .

图4为图1GaAs基低漏电流双悬臂梁开关双栅HEMT两个悬臂梁开关均下拉时的沟道示意图。FIG. 4 is a schematic diagram of the channel of the GaAs-based low-leakage current double-cantilever switch double-gate HEMT in FIG. 1 when both cantilever switches are pulled down.

图5为图1GaAs基低漏电流双悬臂梁开关双栅HEMT只有一个悬臂梁开关下拉时的沟道示意图。FIG. 5 is a schematic diagram of the channel of the GaAs-based low-leakage current double-cantilever switch double-gate HEMT in FIG. 1 when only one cantilever switch is pulled down.

图中有：GaAs衬底1，本征GaAs层2，本征AlGaAs层3，N+AlGaAs层4，源极5，漏极6，栅极7，锚区8，悬臂梁开关9，下拉极板10，绝缘层11，通孔12，引线13，第一端口14，第二端口15，第三端口16，第四端口17。In the figure there are: GaAs substrate 1, intrinsic GaAs layer 2, intrinsic AlGaAs layer 3, N+AlGaAs layer 4, source 5, drain 6, gate 7, anchor region 8, cantilever switch 9, pull-down pole Board 10 , insulating layer 11 , through hole 12 , lead 13 , first port 14 , second port 15 , third port 16 , fourth port 17 .

具体实施方式detailed description

本发明的GaAs基低漏电流双悬臂梁开关双栅HEMT倍频器。包括GaAs衬底、增强型HEMT，以及外接的低通滤波器、压控振荡器、除法器、高频扼流圈；其中HEMT生长在GaAs衬底上，包括本征GaAs层，本征AlGaAs层，N+AlGaAs层；源极，漏极和栅极。栅极与N+AlGAs层形成肖特基接触，本征GaAs层与本征AlGaAs层形成异质结。锚区位于栅极一侧，悬臂梁开关通过锚区横跨于栅极之上。悬臂梁末端下方设置有下拉极板，下拉极板接地，绝缘层覆盖在下拉极板之上。The invention relates to a GaAs-based low-leakage current double-cantilever switch double-gate HEMT frequency multiplier. Including GaAs substrate, enhanced HEMT, and external low-pass filter, voltage-controlled oscillator, divider, high-frequency choke coil; where HEMT is grown on GaAs substrate, including intrinsic GaAs layer, intrinsic AlGaAs layer , N+AlGaAs layer; source, drain and gate. The gate forms a Schottky contact with the N+AlGAs layer, and the intrinsic GaAs layer forms a heterojunction with the intrinsic AlGaAs layer. The anchor region is located on one side of the gate, and the cantilever switch straddles the gate through the anchor region. A pull-down polar plate is arranged below the end of the cantilever beam, the pull-down polar plate is grounded, and an insulating layer covers the pull-down polar plate.

参考信号和反馈信号分别通过锚区加载到两个悬臂梁开关上。直流偏置通过高频扼流圈和锚区作用在悬臂梁开关上。高频扼流圈保证交流信号与直流偏置隔开。The reference signal and the feedback signal are respectively loaded on the two cantilever beam switches through the anchor area. The DC bias is applied to the cantilever switch through the high frequency choke and anchor region. A high-frequency choke keeps the AC signal isolated from the DC bias.

悬臂梁开关的下拉电压设计为HEMT的阈值电压。当直流偏置小于下拉电压，悬臂梁开关不与栅极接触，开关断开时，栅极电压为0，HEMT无法导通，有利于减小栅极漏电流，降低功耗。The pull-down voltage of the cantilever switch is designed to be the threshold voltage of the HEMT. When the DC bias is less than the pull-down voltage, the cantilever beam switch is not in contact with the gate, and when the switch is turned off, the gate voltage is 0, and the HEMT cannot be turned on, which is beneficial to reduce gate leakage current and power consumption.

当直流偏置达到或大于下拉电压，两个悬臂梁开关均与栅极接触时，开关呈闭合状态，肖特基势垒宽度在栅电压作用下变窄，异质结表面形成二维电子气沟道，HEMT导通，参考信号和反馈信号通过HEMT相乘。漏极输出信号包含了两信号之间的相位差信息，经过低通滤波器后，高频分量被滤除，并向压控振荡器输送一个直流电压，压控振荡器输出信号频率被控制电压调节。压控振荡器输出信号经过除法器之后，在频率上对应发生1/N的改变，并作为反馈信号，重新输入悬臂梁开关，经过环路的作用，反馈信号和参考信号频率相等。最终锁相环输出的信号频率为参考频率的N倍，实现倍频。When the DC bias reaches or exceeds the pull-down voltage and both cantilever switches are in contact with the gate, the switch is closed, the Schottky barrier width is narrowed under the action of the gate voltage, and a two-dimensional electron gas is formed on the surface of the heterojunction channel, the HEMT is turned on, and the reference and feedback signals are multiplied by the HEMT. The drain output signal contains the phase difference information between the two signals. After passing through the low-pass filter, the high-frequency component is filtered out, and a DC voltage is sent to the voltage-controlled oscillator. The frequency of the output signal of the voltage-controlled oscillator is controlled by the voltage adjust. After the output signal of the voltage-controlled oscillator passes through the divider, the corresponding 1/N change in frequency occurs, and as a feedback signal, it is re-input into the cantilever switch. After the function of the loop, the frequency of the feedback signal and the reference signal are equal. Finally, the signal frequency output by the phase-locked loop is N times the reference frequency, realizing frequency multiplication.

当只有一个悬臂梁开关下拉闭合与对应的栅极接触时，闭合的开关下方形成二维电子气沟道，另一个断开的开关下方为高阻区，沟道与高阻区串联能够有效的提高HEMT的反向击穿电压。只有选择下拉闭合的悬臂梁开关上的选通信号可以通过HEMT放大输出。从而通过对一个悬臂梁开关的单独控制，实现对单个信号的放大，电路具有多功能，扩大了电路的应用范围。When only one cantilever beam switch is pulled down and closed to contact with the corresponding gate, a two-dimensional electron gas channel is formed under the closed switch, and a high-resistance region is formed under the other open switch, and the channel and the high-resistance region can be effectively connected in series. Improve the reverse breakdown voltage of HEMT. Only the strobe signal on the cantilever switch with the select pull-down closed can be amplified and output by the HEMT. Therefore, through the independent control of a cantilever beam switch, the amplification of a single signal is realized, the circuit has multiple functions, and the application range of the circuit is expanded.

下面结合附图对本发明的GaAs基低漏电流双悬臂梁开关双栅HEMT倍频器做进一步解释。The GaAs-based low-leakage current double-cantilever switch double-gate HEMT frequency multiplier of the present invention will be further explained below in conjunction with the accompanying drawings.

如图1所示，本发明的GaAs基低漏电流双悬臂梁开关双栅HEMT倍频器包括GaAs衬底1，设置在GaAs衬底上的增强型HEMT，外接的低通滤波器，压控振荡器，除法器、高频扼流圈。As shown in Figure 1, the GaAs-based low-leakage current double-cantilever switch double-gate HEMT frequency multiplier of the present invention includes a GaAs substrate 1, an enhanced HEMT arranged on the GaAs substrate, an external low-pass filter, and a voltage-controlled Oscillators, dividers, high frequency chokes.

HEMT包括本征GaAs层2，本征AlGaAs层3，N+AlGaAs层4，源极5，漏极6，栅极7，锚区8，悬臂梁开关9，下拉极板10，绝缘层11，通孔12，引线13。其中，源极5接地，锚区8设置在栅极7一侧，下拉极板10设置在悬臂梁开关9的末端下方，与地连接，悬臂梁开关9通过锚区8横跨在栅极上方。在HEMT结构中，栅极7与N+AlGaAs层4形成肖特基接触，本征AlGaAs层3与本征GaAs层2形成异质结。对于增强型HEMT，栅电压为0时，肖特基接触势垒耗尽了异质结界面的二维电子气，没有导通沟道。HEMT includes intrinsic GaAs layer 2, intrinsic AlGaAs layer 3, N+AlGaAs layer 4, source 5, drain 6, gate 7, anchor region 8, cantilever switch 9, pull-down plate 10, insulating layer 11, Through hole 12, lead wire 13. Wherein, the source 5 is grounded, the anchor region 8 is arranged on one side of the gate 7, the pull-down plate 10 is arranged under the end of the cantilever switch 9 and connected to the ground, and the cantilever switch 9 straddles the gate through the anchor region 8 . In the HEMT structure, the gate 7 forms a Schottky contact with the N+AlGaAs layer 4 , and the intrinsic AlGaAs layer 3 forms a heterojunction with the intrinsic GaAs layer 2 . For the enhanced HEMT, when the gate voltage is 0, the Schottky contact barrier depletes the two-dimensional electron gas at the heterojunction interface, and there is no conduction channel.

HEMT漏极6输出信号有两种工作方式，一种是通过第一端口14接入低通滤波器，低通滤波器输出接入压控振荡器，压控振荡器输出通过第三端口16接入除法器，除法器的输出信号作为反馈信号通过锚区8接入一个悬臂梁开关9上，参考信号通过锚区8接入另一个悬臂梁开关9上。HEMT漏极6输出信号的另一种工作方式是选择第二端口15直接输出。The output signal of the HEMT drain 6 has two working modes, one is to connect the low-pass filter through the first port 14, the output of the low-pass filter is connected to the voltage-controlled oscillator, and the output of the voltage-controlled oscillator is connected to the third port 16 The output signal of the divider is connected to a cantilever switch 9 through the anchor area 8 as a feedback signal, and the reference signal is connected to another cantilever switch 9 through the anchor area 8. Another working mode for the output signal of the HEMT drain 6 is to select the second port 15 to output directly.

直流偏置通过高频扼流圈和锚区8作用在悬臂梁开关上。高频扼流圈保证直流偏置与交流信号隔开，悬臂梁开关9的下拉电压设计为HEMT的阈值电压。当直流偏置小于下拉电压，悬臂梁开关9不与栅极7接触，开关呈断开状态时，栅电压为0，异质结界面没有二维电子气沟道，HEMT截止，有利于减小栅极漏电流，降低功耗。The DC bias is applied to the cantilever beam switch through the high frequency choke coil and the anchor region 8 . The high-frequency choke coil ensures that the DC bias is separated from the AC signal, and the pull-down voltage of the cantilever switch 9 is designed to be the threshold voltage of the HEMT. When the DC bias is less than the pull-down voltage, the cantilever switch 9 is not in contact with the gate 7, and the switch is in the off state, the gate voltage is 0, there is no two-dimensional electron gas channel at the heterojunction interface, and the HEMT is cut off, which is beneficial to reduce gate leakage current, reducing power dissipation.

当直流偏置达到或大于下拉电压，两个悬臂梁开关9均下拉与栅极7接触，开关闭合时，在栅电压的作用下，二维电子气在异质结界面聚集，形成沟道，如图4所示，HEMT导通。参考信号和反馈信号通过HEMT相乘。漏极6输出信号包含了两信号之间的相位差信息，选择第一端口14输入低通滤波器，低通滤波器将此信号中的高频分量滤除，并向压控振荡器输送一个直流电压，直流电压可以表示为：When the DC bias reaches or exceeds the pull-down voltage, the two cantilever beam switches 9 are pulled down and contact the gate 7, and when the switch is closed, under the action of the gate voltage, the two-dimensional electron gas gathers at the heterojunction interface to form a channel, As shown in Figure 4, the HEMT is turned on. The reference signal and feedback signal are multiplied by HEMT. The output signal of the drain 6 contains the phase difference information between the two signals, select the first port 14 to input the low-pass filter, the low-pass filter will filter out the high-frequency components in this signal, and send a DC voltage, DC voltage can be expressed as:

其中K为HEMT增益系数，f_ref为参考信号频率，f_back为反馈信号频率，φ为固有相位差。压控振荡器在直流电压的控制下，调节输出信号频率的大小。压控振荡器输出频率可以通过以下微分表示式表达：Among them, K is the HEMT gain coefficient, f _ref is the reference signal frequency, f _back is the feedback signal frequency, and φ is the inherent phase difference. The voltage-controlled oscillator adjusts the frequency of the output signal under the control of the DC voltage. The VCO output frequency can be expressed by the following differential expression:

其中，f_o为压控振荡器输出频率，K_v为压控振荡器灵敏度。经过除法器后，压控振荡器的输出频率变为原来的1/N，并作为反馈信号，重新输入HEMT。也就是：Among them, f _o is the output frequency of the voltage-controlled oscillator, and K _v is the sensitivity of the voltage-controlled oscillator. After the divider, the output frequency of the voltage-controlled oscillator becomes 1/N of the original, and as a feedback signal, it is re-input into the HEMT. That is:

经过反馈循环作用，反馈信号的频率最终和参考信号一致。即：After a feedback loop, the frequency of the feedback signal is finally consistent with the reference signal. which is:

所以，最终压控振荡器第四端口17输出的信号频率为参考频率的N倍,实现参考信号的倍频。Therefore, finally, the frequency of the signal output by the fourth port 17 of the voltage-controlled oscillator is N times of the reference frequency, realizing the frequency multiplication of the reference signal.

只有一个悬臂梁开关9被下拉闭合，另一个悬臂梁开关9处于悬浮断开状态时，闭合的悬臂梁开关9下方形成二维电子气沟道，断开的悬臂梁开关9下方为高阻区，如图5所示，沟道与高阻区串联，有利于提高反向击穿电压。只有闭合的悬臂梁开关9上的选通信号可以通过HEMT放大，放大信号选择第二端口15输出。当只有加载参考信号的悬臂梁开关9闭合时，参考信号通过HEMT放大，第二端口15输出频率为f_ref的放大信号。当只有加载反馈信号的悬臂梁开关9闭合时，反馈信号频率为压控振荡器频率经过除法器后的结果，即f_o/N，所以，第二端口15输出频率为f_o/N的放大信号。从而通过对一个悬臂梁开关9的单独控制，实现对单个信号的放大，扩大了电路的应用范围。此外，断开的悬臂梁开关9有利于减小栅极漏电流，降低功耗。When only one cantilever switch 9 is pulled down and closed, and the other cantilever switch 9 is suspended and disconnected, a two-dimensional electron gas channel is formed under the closed cantilever switch 9, and a high-resistance area is formed under the disconnected cantilever switch 9 , as shown in Figure 5, the channel is connected in series with the high-resistance region, which is beneficial to improve the reverse breakdown voltage. Only the strobe signal on the closed cantilever beam switch 9 can be amplified by the HEMT, and the amplified signal selects the second port 15 for output. When only the cantilever switch 9 loaded with the reference signal is closed, the reference signal is amplified by the HEMT, and the second port 15 outputs an amplified signal with a frequency f _ref . When only the cantilever beam switch 9 that loads the feedback signal is closed, the frequency of the feedback signal is the result of the voltage-controlled oscillator frequency passing through the divider, that is, f _o /N, so the output frequency of the second port 15 is the amplification of f _o /N Signal. Therefore, through the individual control of a cantilever beam switch 9, the amplification of a single signal is realized, and the application range of the circuit is expanded. In addition, the disconnected cantilever beam switch 9 is beneficial to reduce gate leakage current and reduce power consumption.

本发明的GaAs基低漏电流双悬臂梁开关双栅HEMT倍频器的制备方法如下：The preparation method of the GaAs-based low-leakage current double-cantilever switch double-gate HEMT frequency multiplier of the present invention is as follows:

1)在半绝缘P型GaAs衬底；1) On a semi-insulating P-type GaAs substrate;

2)外延生长本征GaAs层约500nm；2) epitaxial growth of intrinsic GaAs layer about 500nm;

3)外延生长本征AlGaAs隔离层约50nm；3) epitaxial growth of intrinsic AlGaAs isolation layer about 50nm;

4)生长N+型AlGaAs层约20nm，掺杂浓度为1×10¹⁸cm^-3，控制厚度与掺杂浓度，使得HEMT管为增强型；4) Grow an N+-type AlGaAs layer of about 20nm, with a doping concentration of 1×10 ¹⁸ cm ^-3 , and control the thickness and doping concentration to make the HEMT tube an enhancement type;

5)生长N+型GaAs层厚约300nm，掺杂浓度为3.5×10¹⁸cm^-3；5) growing an N+ type GaAs layer with a thickness of about 300nm and a doping concentration of 3.5×10 ¹⁸ cm ^-3 ;

6)台面腐蚀隔离有源区；6) Mesa etching to isolate the active area;

7)生长氮化硅；7) growing silicon nitride;

8)光刻氮化硅层，刻出源漏极域，进行N+离子注入，形成源极和漏极，去除氮化硅；8) Photoetching the silicon nitride layer, carving out the source and drain regions, performing N+ ion implantation, forming the source and drain electrodes, and removing the silicon nitride;

9)涂覆光刻胶，光刻去除电极接触位置的光刻胶；9) Coating photoresist, and photolithography removes the photoresist at the electrode contact position;

10)真空蒸发金锗镍/金；10) Vacuum evaporation of gold germanium nickel/gold;

11)剥离，合金化形成源、漏欧姆接触电极；11) Stripping and alloying to form source and drain ohmic contact electrodes;

12)涂覆光刻胶，光刻去除栅极位置的光刻胶；12) Apply photoresist, and remove the photoresist at the gate position by photolithography;

13)生长厚度为0.5μm Ti/Pt/Au；13) The growth thickness is 0.5μm Ti/Pt/Au;

14)去除光刻胶以及光刻胶上的金属，形成肖特基接触的栅极；14) removing the photoresist and the metal on the photoresist to form a Schottky contact gate;

15)涂覆光刻胶，光刻出引线，下拉极板和悬臂梁锚区的窗口；15) Coating photoresist, photoetching out leads, and pulling down the windows of the pole plate and the anchor area of the cantilever beam;

16)生长一层厚度为0.3μm的Au；16) growing a layer of Au with a thickness of 0.3 μm;

17)去除光刻胶，形成引线、下拉极板、悬臂梁的锚区；17) Removing the photoresist to form lead wires, pull-down polar plates, and anchor regions for cantilever beams;

18)沉积绝缘层，应用外延工艺生长0.1μm的Si_xN_1-x的绝缘层；18) Depositing an insulating layer, and growing a 0.1 μm Si _x N _1-x insulating layer by using an epitaxial process;

19)光刻去除多余的绝缘层，仅保留下拉极板上方的绝缘层；19) Photolithography removes the excess insulating layer, leaving only the insulating layer above the pull-down plate;

20)通过旋涂方式形成PMGI牺牲层，然后光刻牺牲层，仅保留悬臂梁下方的牺牲层；20) Form a PMGI sacrificial layer by spin coating, and then photolithography the sacrificial layer, leaving only the sacrificial layer under the cantilever beam;

21)生长一层用于电镀的底金：蒸发Ti/Au/Ti，作为种子层厚度50/150/30nm；21) Grow a layer of base gold for electroplating: evaporate Ti/Au/Ti as a seed layer with a thickness of 50/150/30nm;

22)涂覆光刻胶，光刻出悬臂梁，锚区和连接线的窗口；22) Coating photoresist, and photoetching the windows of the cantilever beam, the anchor region and the connection line;

23)电镀一层金，其厚度为2μm；23) electroplating a layer of gold with a thickness of 2 μm;

24)去除光刻胶，同时去除光刻胶上的金层；24) remove the photoresist, and simultaneously remove the gold layer on the photoresist;

25)反刻钛/金/钛，腐蚀种子层，形成悬臂梁及以及连接线；25) Anti-engraving titanium/gold/titanium, corroding the seed layer, forming cantilever beams and connecting lines;

26)去除聚酰亚胺牺牲层，释放MEMS悬臂梁；26) remove the polyimide sacrificial layer, and release the MEMS cantilever beam;

27)将制备的HEMT与外部电路连接，构成倍频器。27) Connect the prepared HEMT with an external circuit to form a frequency multiplier.

区分是否为该结构的标准如下：The criteria for distinguishing whether it is the structure are as follows:

本发明的GaAs基低漏电流双悬臂梁开关双栅HEMT倍频器，参考信号和反馈信号分别加载在两个悬臂梁开关上，直流偏置通过锚区作用在悬臂梁开关上，悬臂梁的下拉电压设计为HEMT的阈值电压。当两个悬臂梁开关均处于悬浮断开状态时，栅电压为0，HEMT截止。当两个悬臂梁开关均通过直流偏置下拉闭合状态，与栅极接触时，二维电子气沟道形成，HEMT导通。参考信号和反馈信号通过HEMT相乘输，漏极输出包含两信号的相位信息，经过低通滤波器，压控振荡器、除法器反馈循环后得到参考信号频率N倍的倍频信号。另外，单个悬臂梁开关闭合，另一个断开的悬臂梁开关下方形成高阻区，有利于提高HEMT的反向击穿电压，并且可以实现对单个选通信号的放大，电路具有多功能性。In the GaAs-based low-leakage current double-cantilever switch double-gate HEMT frequency multiplier of the present invention, the reference signal and the feedback signal are respectively loaded on the two cantilever switches, and the DC bias acts on the cantilever switch through the anchor region. The pull-down voltage is designed to be the threshold voltage of the HEMT. When the two cantilever beam switches are in the floating off state, the gate voltage is 0, and the HEMT is cut off. When the two cantilever beam switches are pulled down to the closed state by the DC bias and contact the gate, a two-dimensional electron gas channel is formed, and the HEMT is turned on. The reference signal and the feedback signal are multiplied and output by the HEMT, and the drain output contains the phase information of the two signals. After a low-pass filter, a voltage-controlled oscillator, and a divider feedback loop, a frequency multiplied signal of N times the frequency of the reference signal is obtained. In addition, a single cantilever beam switch is closed, and a high-resistance area is formed under another open cantilever beam switch, which is conducive to improving the reverse breakdown voltage of HEMT, and can realize the amplification of a single gating signal, and the circuit has versatility.