公开(公告)号：US4747161A

公开(公告)日：1988-05-24

申请号：US832807

申请日：1986-02-25

申请人： Gilmer L. Hulsey ,  Bryan A. Weaver

发明人： Gilmer L. Hulsey ,  Bryan A. Weaver

IPC分类号： H03C1/02 ,  H03F1/30 ,  H04B1/04 ,  H04B1/16

CPC分类号： H03C1/02 ,  H03F1/30 ,  H04B1/0475 ,  H04B1/1607 ,  H04B1/04

摘要： An AM-RF transmitter includes a transmitter stage having a DC power supply terminal energized by an AC to DC converter including reactances having a resonant frequency approaching frequencies of an information, modulating signal. The voltage applied by the supply to the DC power supply terminal is reduced to such an extent as to induce distortion in the transmitted AM-RF carrier in response to the transmitter stage being modulated by positive amplitude variations having frequencies that approach the resonant frequency. The amplitude of the transmitter stage modulation is increased when the distortion would otherwise occur to substantially prevent the distortion. The information signal is modified in amplitude by only AC coupling a replica of the DC power supply voltage variations to one input of a four quadrant multiplier, having a second input responsive to the information signal.

摘要翻译： AM-RF发射机包括具有由AC到DC转换器激励的直流电源端子的发射机级，其包括具有接近信息频率的调制信号的谐振频率的电抗。 电源施加到直流电源端子的电压减小到这样一个程度，以便响应于发射机级被具有接近谐振频率的频率的正幅度变化来调制而在发射的AM-RF载波中引起失真。 发生器级调制的幅度会增加，否则将发生失真以基本上防止失真。 通过仅将DC电源电压变化的副本交流耦合到四象限乘法器的一个输入端，响应于信息信号具有第二输入，信号信号被修改。

公开(公告)号：US4776036A

公开(公告)日：1988-10-04

申请号：US119868

申请日：1987-11-13

申请人： Gilmer L. Hulsey ,  Bryan A. Weaver

发明人： Gilmer L. Hulsey ,  Bryan A. Weaver

IPC分类号： H03C1/16 ,  H04B1/04

CPC分类号： H03C1/16

摘要： An RF-AM transmitter includes a pulse amplifier responsive to a pulse width modulated (PWM) signal derived in response to an information signal. A low pass filter converts pulses derived by the power amplifier into a variable amplitude signal that is DC coupled to a power supply for an RF amplifier. An amplifier system including the pulse and RF amplifiers has stray capacitance coupled to a modulator which derives the PWM signal; the stray capacitance lengthens narrow modulator output pulses so they are excessively long. The amplitude of only the narrow pulses is reduced by a resistor-capacitor timing circuit in series with a switch to substantially preserve the narrow pulse area. The switch provides a low impedance path from the timing circuit to a reference potential terminal when current initially flows in the circuit during pulse transitions and throughout the length of each of the short duration pulses. Thereby, the power amplifier is forward biased but not driven into saturation during the short duration pulses. The switch provides a higher impedance path from the timing circuit to the reference potential terminal after the transition has elapsed, enabling the power amplifier to be saturated during pulses longer than the short duration pulses. The RF power amplifier tube has a tendency to load the power amplifier tube out of saturation during wide pulses. The ampitude of the wide pulses is maintained substantially constant by a resistor shunted by an inductor between the modulator and the power amplifier.

摘要翻译： RF-AM发射机包括响应于信号信号导出的脉宽调制（PWM）信号的脉冲放大器。 低通滤波器将由功率放大器导出的脉冲转换为与RF放大器的电源直流耦合的可变幅度信号。 包括脉冲和RF放大器的放大器系统具有耦合到导出PWM信号的调制器的杂散电容; 杂散电容会延长窄调制器输出脉冲，使其过长。 只有窄脉冲的幅度通过与开关串联的电阻器 - 电容器定时电路来减小，以基本上保持窄脉冲区域。 当电流最初在脉冲转换期间在电路中流动并且在每个短持续时间脉冲的整个长度期间，该开关提供从定时电路到参考电位端子的低阻抗路径。 因此，功率放大器是正向偏置的，但在短时间脉冲期间不被驱动成饱和。 在转换过去之后，开关提供从定时电路到参考电位端子的较高阻抗路径，使得功率放大器在比短持续时间脉冲更长的脉冲期间饱和。 RF功率放大器管在宽脉冲期间具有将功率放大器管装入饱和度的趋势。 通过由调制器和功率放大器之间的电感器分流的电阻器，宽脉冲的幅度保持基本恒定。