公开(公告)号：US3995236A

公开(公告)日：1976-11-30

申请号：US510615

申请日：1974-09-30

申请人： Clifford E. Mueller ,  William E. Mears

发明人： Clifford E. Mueller ,  William E. Mears

IPC分类号： G01S1/50 ,  H03C1/58 ,  H03C1/14 ,  H03D1/24

CPC分类号： G01S1/50 ,  H03C1/58

摘要： A modulator employs a pair of variable RF attenuators to produce a double sideband, suppressed carrier output. The attenuator devices are PIN diodes which are rendered alternately conductive in synchronism with the recurring half cycles of the audio frequency input signal which is to be impressed upon the radio frequency signal as modulation. As each diode conducts the RF signal, its attenuation is varied by a control signal in a manner to provide the conducted RF signal with a modulation envelope that follows the amplitude of the audio input. The modulated signals from both diodes are combined at the modulator output, after a phase reversal of the modulated signal from one of the diodes, in order to thereby provide a double sideband, suppressed carrier output signal. The control signal for each conducting diode is produced by a function generator operating within a closed loop feedback system. The generator receives the audio input and a recreated modulating signal derived without carrier insertion from an envelope detector on the modulator output, and compares the recreated modulation with the original audio input to provide the control signal with the proper wave shape. An electronic goniometer for a VOR navigation system employs two of the double sideband modulators responsive to 30 Hz input signals that are 90.degree. out of phase; thus a 90.degree. modulation envelope phase difference exists at the goniometer outputs as required for the variable phase antenna feeds of a VOR transmitting system.

摘要翻译： 调制器采用一对可变RF衰减器来产生双边带，抑制载波输出。 衰减器件是PIN二极管，它们与要作为调制对射频信号施加的音频输入信号的循环半周期同步地交替导通。 当每个二极管导通RF信号时，其衰减以控制信号改变，以便向传导的RF信号提供跟随音频输入的幅度的调制包络。 在来自二极管之一的调制信号的相位反相之后，来自两个二极管的调制信号在调制器输出端被组合，从而提供双边带抑制的载波输出信号。 每个导通二极管的控制信号由在闭环反馈系统内运行的功能发生器产生。 发生器接收音频输入，并且在调制器输出上从包络检测器接收到未载波插入的重新产生的调制信号，并将重新创建的调制与原始音频输入进行比较，以提供具有适当波形的控制信号。 用于VOR导航系统的电子测角仪采用两个双边带调制器，响应于90°异相的30 Hz输入信号; 因此在VOR发射系统的可变相位天线馈送所需的测角器输出处存在90度调制包络相位差。

公开(公告)号：US4024459A

公开(公告)日：1977-05-17

申请号：US649464

申请日：1976-01-15

申请人： William E. Mears

发明人： William E. Mears

IPC分类号： G01R19/04 ,  G01R19/175 ,  H03K5/1536 ,  H03K5/20 ,  H03K9/06

CPC分类号： H03K5/1536 ,  G01R19/04 ,  G01R19/175

摘要： The peak amplitudes of alternating components of a composite alternating signal are determined without separating the components from one another, where such components are of different frequencies but have substantially in-phase zero crossings at recurring intervals. In an instrument landing system for aircraft, 90 Hz and 150 Hz signals form the components of a composite modulating signal and the zero crossing points of both components are accurately controlled. The composite 90 and 150 Hz signal is examined by a circuit which produces a reference pulse at the zero crossing time of both component frequencies in the positive direction. The reference pulses maintain digital timing circuitry in synchronism with the 90 Hz and 150 Hz components, and the composite wave form is sampled at each frequency to synchronously detect the peak amplitude of each component in separate detector circuits.

摘要翻译： 确定复合交变信号的交替分量的峰值振幅，而不将这些分量彼此分离，其中这些分量具有不同的频率，但是在重复间隔处具有基本上同相的零交叉。 在用于飞机的仪表着陆系统中，90Hz和150Hz信号形成复合调制信号的组件，并且两个部件的过零点被精确地控制。 通过在正方向上的两个分量频率的过零时间产生参考脉冲的电路检查复合90和150Hz信号。 参考脉冲保持数字定时电路与90 Hz和150 Hz分量同步，并且复合波形在每个频率进行采样，以同步检测单独检测器电路中每个分量的峰值幅度。

公开(公告)号：US3938155A

公开(公告)日：1976-02-10

申请号：US488582

申请日：1974-07-15

申请人： William E. Mears ,  Clifford E. Mueller ,  David M. Staehling

发明人： William E. Mears ,  Clifford E. Mueller ,  David M. Staehling

IPC分类号： G01S1/02 ,  G01S19/11 ,  G01S1/08

CPC分类号： G01S1/02

摘要： In an instrument landing system for aircraft, the transmitter is required to produce an amplitude modulated signal comprising a carrier wave having sidebands containing the sum of a 90 Hz and a 150 Hz signal as modulation, and to also produce a double sideband, suppressed carrier signal in which the modulation is the difference between the 90 Hz and 150 Hz signals. In the present invention, the 90 Hz and 150 Hz signals are summed to provide a composite modulating signal that is employed to directly modulate the radio frequency carrier. To provide the double sideband signal the carrier is fed to a 180.degree. phase shift network, and the carrier and the network output are alternately delivered to a modulated amplifier stage by an RF switch which is operated with each change in the sign of a difference signal derived from the 90 Hz and 150 Hz signals. Accordingly, the output from the RF switch is a phasechanging carrier that undergoes a phase reversal with each change in the polarity of the difference signal. This phase-changing carrier is modulated with a modulating signal that is the absolute value of the difference signal, and the resultant is the desired double sideband, suppressed carrier output. A high gain operational amplifier in conjunction with an envelope detector in a negative feedback loop is employed with both the AM and the DSB modulators to insure high stability.

摘要翻译： 在用于飞行器的仪表着陆系统中，发射机需要产生一个幅度调制信号，该幅度调制信号包括载波，该载波具有包含90Hz和150Hz信号之和的边带作为调制，并且还产生双边带，抑制的载波信号 其中调制是90Hz和150Hz信号之间的差异。 在本发明中，将90Hz和150Hz信号相加以提供用于直接调制射频载波的复合调制信号。 为了提供双边带信号，载波被馈送到180°相移网络，并且载波和网络输出通过RF开关交替地传送到调制放大器级，RF开关随着差分信号的符号的每个改变而被操作 衍生自90 Hz和150 Hz信号。 因此，来自RF开关的输出是随着差信号的极性的每个变化而经历相位反转的相变载波。 该相变载波用作为差分信号的绝对值的调制信号进行调制，结果是期望的双边带，抑制载波输出。 与负反馈环路中的包络检测器结合使用的高增益运算放大器与AM和DSB调制器一起使用以确保高稳定性。