调幅发射机的仿真设计

1、目录系统分析模块电路设计整体电路系统分析缓冲隔离级功放级音频放大级主振级（产生6M载波）调幅调制级调幅发射机的主要任务是完成有用的低频信号对高频载波的调制，将其变为在某一中心频率上具有一定带宽、适合通过天线发射的电磁波音频信号模块电路设计Q22N2222AR12kR25.7kR43.8kC1100pFC21nFL115HCe110nFCb110nFC330pFKey=A86 %C430pFKey=A50 %R66kKey=A20 %XFC1123R31kC50.01FVCC12VL256HC60.01FQ32N930Rb27.9kCc115pFRe31kKey=A45 %Rb410kRe410

2、C70.022FR51kKey=A95 %XSC1ABExt Trig+_+_主振级和缓冲级主振级：克拉泼电路（电容三段式产生的波形较好，且适合产生高频的振荡）缓冲级：采用三极管构成的射极跟随器模块电路设计音频放大级仿真电路U1TDA2030U+U-12354C1100FC20.1UFR122KVSS-12VVCC12VD11N4001C31UFR2680C422FD21N4001R322KC5100UFC60.1UFR41C70.1UFXFG1XSC1ABExt Trig+_+_TDA2030A是一种音频功放电路，该集成电路广泛应用于汽车立体声收录音机、中功率音响设备，具有体积小、输出功率大

3、、失真小等特点。并具有内部保护电路。采用双电源供电的方式仿真结果:电压增益为66模块电路设计调幅调制级Q12N2222Q32N2222Q42N2222Q52N2222Q22N2222Q62N2222Q72N2222Q82N2222R1500R2500R3500R41kR551C10.1FC210FR61kR71000Key=A85 %R81kR951R1051VCC12VGNDXFG1R111kC30.1FGNDC410FR126.8kVEE-8VR131kR143.9kR153.9kC522nFXSC1ABExt Trig+_+_GNDXFG2D11N1202C振幅调制即用低频信号去控制高频

4、信号，使输出的信号幅值随低频信号变化，实现将低频信号搬移到高频段，达到远距离传输的目的。本振幅调制级采用模拟相乘器MC1496实现模块电路设计调幅调制级Q12N2222Q32N2222Q42N2222Q52N2222Q22N2222Q62N2222Q72N2222Q82N2222IO1R1500R2500R3500D11N1200CIO2IO3IO14IO12IO4IO5IO8IO10IO6MC1496模拟乘法器模块电路设计调幅调制级仿真结果模块电路设计功放级Q112N2102R2610kC200.01FVCC12VL356HT1C210.01FC220.01FL456HC230.01FQ12

5、2N5551R2710kR28500Key=A100 %R291kQ132N5551R3010kR313kC250.022FR3251R33510C260.01FR3410R35150C270.01FC28500pFT2XSC3ABExt Trig+_+_C24350pFKey=A85 %R363kIO1缓冲级：射极跟随器，用于缓冲和滤波。激励级：放大电压功放级：功率放大整体电路Q12N2222Q22N2222Q32N2222Q42N2222Q52N2222Q62N2222Q72N2222Q82N2222R1500R2500R3500R41kR551C10.1FC210FR61kR71000K

6、ey=A85 %R81kR951R1051R111kC30.1FC410FR126.8kVEE-8VR131kR143.9kR153.9kC522nFD11N1202CU1TDA2030U+U-12354C6100FC70.1UFR1622KVSS-12VD21N4001C81UFR17680C922FD31N4001R1822KC10100UFC110.1UFR191C120.1UFXFG1Q92N930Rb17.9kCc115pFRe11kKey=A5 %Rb210kRe210C130.022FQ102N2222AR202kR215.7kR223.8kC14100pFC151nFL115H

7、Ce110nFCb110nFC1630pFKey=A66 %C1730pFKey=A50 %R236kKey=A20 %XFC1123R241kR251kKey=A25 %C180.01FL256HC190.01FQ112N2102R2610kC200.01FVCC12VL356HT1C210.01FC220.01FL456HC230.01FQ122N5551R2710kR28500Key=A100 %R291kQ132N5551R3010kR313kC250.022FR3251R33510C260.01FR3410R35150C270.01FC28500pFT2XSC3ABExt Trig+_+_T3C24350pFKey=A85 %R363kXSC1ABExt Trig+_+_整体电路仿真结果：不太符合项目要求，波形有失真，发射频率也变小了整体电路调试分析1 本振与缓冲联调时：在输出端应接负载电阻RL，RL应与下一级电路的等效输入阻抗相等输入阻抗的测试方法:在下一级电路的输入端加上测试探针，然后利用交流表达式分析探针处的相位和幅值。如图电路的阻抗幅值为51.5980，相位为62.01942 本振级、隔离放大级、音频放大级以及调制级联调时，经常会出现过调幅。可能是经发射极跟随器输出的本振电压偏小或是话音放大级输出的调制电压V过大。调节使Vo=100mV150mV，并测量调制