公开(公告)号：US4455673A

公开(公告)日：1984-06-19

申请号：US401222

申请日：1982-07-23

申请人： Douglas R. P. Topping ,  David W. Walton ,  Leslie R. Sage

发明人： Douglas R. P. Topping ,  David W. Walton ,  Leslie R. Sage

IPC分类号： H04S7/00 ,  H04H5/00

CPC分类号： H04S7/40

摘要： In a circuit for indicating reception of stereo signals (for use in e.g. a radio tuner or television) audio signals prevailing in the left (L) and right (R) output channels are applied to respective limiting circuit and the output signals derived are fed to OR gate. When a monoaural signal is detected, the signals in the two output channels will be in coincidence and so the output from the exclusive OR gate remains low. When stereo signals are detected, however, a finite phase difference exists between the two signals and the output for the OR gate is correspondingly high. A Schmitt trigger drives an LED display whenever the output from the OR gate exceeds a preset threshold level to provide an indication that a stereo signal is being reproduced. A capacitor/resistor circuit imposes a time delay on level changes at gate so that the LED display remains illuminated, even during momentary interruptions of the audio signal.

摘要翻译： 在用于指示立体声信号的接收的电路（用于例如无线电调谐器或电视机）中，左（L）和右（R）输出通道中存在的音频信号被施加到相应的限制电路，并且所导出的输出信号被馈送到 或门。 当检测到单声道信号时，两个输出通道中的信号将重合，因此异或门的输出保持为低电平。 然而，当检测到立体声信号时，两个信号之间存在有限的相位差，并且OR门的输出相应地较高。 每当“或”门的输出超过预设阈值电平时，施密特触发器就会驱动LED显示屏，以提供正在再现立体声信号的指示。 电容/电阻电路对栅极的电平变化施加时间延迟，使得即使在音频信号的瞬间中断期间，LED显示屏也保持点亮。

公开(公告)号：US4417349A

公开(公告)日：1983-11-22

申请号：US92463

申请日：1979-11-08

申请人： Michael Hills ,  Clay Durret ,  William Von Meister

发明人： Michael Hills ,  Clay Durret ,  William Von Meister

IPC分类号： H04B14/08 ,  H04H20/34 ,  H04L25/49 ,  H04L27/10 ,  H04H5/00 ,  H04L25/03

CPC分类号： H04L27/10 ,  H04B14/08 ,  H04H20/34 ,  H04L25/4906

摘要： A system and method for transferring digital data via the sub-carrier of a commercial broadcast FM radio station. Digital data generated by an originating subscriber is shaped with substantially a raised cosine response in the time domain. The shaped signal is then pre-emphasized and used to frequency modulate (direct angle modulate) a sub-carrier. The sub-carrier in turn frequency modulates the carrier and the data is transmitted by the radio station along with its commercial program. A receiving subscriber detects the sub-carrier and decodes and displays the originated data.

摘要翻译： 一种用于经由商用广播FM无线电台的子载波传送数字数据的系统和方法。 由始发用户产生的数字数据在时域中基本上具有升余弦响应。 然后将成形信号预先强调并用于对副载波进行频率调制（直角调制）。 副载波又对载波进行频率调制，数据由无线电台与其商业程序一起发送。 接收用户检测子载波并解码并显示发起的数据。

公开(公告)号：US4406922A

公开(公告)日：1983-09-27

申请号：US295185

申请日：1981-08-21

申请人： Norman W. Parker ,  Francis H. Hilbert

发明人： Norman W. Parker ,  Francis H. Hilbert

IPC分类号： H04H20/88 ,  H04H5/00

CPC分类号： H04H20/88

摘要： The signal transmitted is a compatible amplitude modulated carrier with amplitude directly proportional to the monaural information or 1+L+R up to a frequency near the upper end of the normal program spectrum. Above the transition region, the amplitude becomes a pure quadrature function. The instantaneous phase varies as a function of the quadrature phase relationship. Transmitter and receiver embodiments are disclosed.

摘要翻译： 发射的信号是幅度调制载波，其幅度与单声道信息或1 + L + R成正比，直到接近正常节目频谱上端的频率。 在过渡区域之上，振幅变为纯正交函数。 瞬时相位作为正交相位关系的函数而变化。 公开了发射机和接收机实施例。

公开(公告)号：US4405837A

公开(公告)日：1983-09-20

申请号：US218878

申请日：1980-12-22

申请人： Lawrence M. Ecklund

发明人： Lawrence M. Ecklund

IPC分类号： H04L27/00 ,  H04B5/00 ,  H04H1/00 ,  H04H20/49 ,  H04H20/88 ,  H04Q9/10 ,  H04H5/00

CPC分类号： H04H20/49

摘要： A low frequency tone detector filters out higher frequencies, then a latching circuit locks on when a given number of low frequency cycles are detected which have at least a predetermined peak amplitude. Thereafter, only a second given number of missing or low amplitude cycles will reset the latch. The circuit is particularly suited to use with AM stereophonic signals where a low frequency tone is added to the difference channel for providing mono/stereo indication and mode switching. The circuit can also provide an early detect for use by a scanning circuit in a receiver.

摘要翻译： 低频音检测器滤除较高频率，然后当检测到具有至少预定峰值振幅的给定数量的低频周期时，锁存电路锁定。 此后，只有第二个给定数量的丢失或低幅度周期将复位锁存器。 该电路特别适用于AM立体声信号，其中将低频音调添加到差分通道以提供单声道/立体声指示和模式切换。 电路还可以提供早期检测以供接收机中的扫描电路使用。

公开(公告)号：US4404430A

公开(公告)日：1983-09-13

申请号：US323374

申请日：1981-11-20

申请人： Minoru Ogita

发明人： Minoru Ogita

IPC分类号： H03D1/22 ,  H04H1/00 ,  H04H40/45 ,  H04H40/63 ,  H04H5/00 ,  H03B19/00

CPC分类号： H04H40/63 ,  H03D1/2236

摘要： An FM stereo demodulation circuit comprises a resistor voltage dividing network having a plurality of outputs; a first switch circuit having a plurality of analog switches which respectively couple the outputs of the voltage dividing network to a first output terminal; a second switch circuit having a plurality of analog switches which respectively couple the outputs of the voltage dividing network to a second output terminal; and a switch control circuit which sequentially enables the analog switches of the first and second switch circuits over one cycle period of a subscarrier signal in response to a pilot signal in an FM stereo composite signal. The circuits produce a staircase-wave multiplying signal having a waveshape which depends on the setting of the resistance values of resistors of the voltage dividing network. The FM stereo composite signal having the pilot signal therein or the pilot signal removed therefrom prior to demodulation is applied to the voltage dividing network so that the FM stereo composite signal is multiplied by the multiplying signal to accomplish the FM stereo demodulation.

摘要翻译： FM立体声解调电路包括具有多个输出的电阻分压网络; 第一开关电路，具有分别将分压网络的输出耦合到第一输出端子的多个模拟开关; 第二开关电路，具有将分压网络的输出分别耦合到第二输出端子的多个模拟开关; 以及开关控制电路，其响应于FM立体声复合信号中的导频信号，在子载波信号的一个周期周期上顺序启用第一和第二开关电路的模拟开关。 这些电路产生具有取决于分压网络的电阻器的电阻值的设置的波形的阶梯波乘法信号。 其中具有导频信号的FM立体声复合信号或在解调之前从其中去除的导频信号被施加到分压网络，使得FM立体声复合信号乘以乘法信号以完成FM立体声解调。

公开(公告)号：US4394537A

公开(公告)日：1983-07-19

申请号：US272549

申请日：1981-06-11

申请人： Kenji Shima ,  Masahiro Hibino

发明人： Kenji Shima ,  Masahiro Hibino

IPC分类号： H04S1/00 ,  H04H5/00

CPC分类号： H04S1/002

摘要： A sound reproducing device particularly adapted for use in the passenger compartment of an automobile and having improved stereo separation and symmetrical frequency characteristics. The device includes a high-pass filter circuit for passing, when a leakage signal occurs, a signal of equal frequency component to the leakage signal, an attenuation circuit for attenuating the level of the signal passed through the filter circuit to the level of the leakage signal, and a phase inverting circuit for inverting the phase of the signal thus attenuated so as to be opposite to that of the leakage signal, thereby to cancel out the leakage signal.

摘要翻译： 一种特别适用于汽车乘客室并具有改进的立体声分离和对称频率特性的声音再现装置。 该装置包括高通滤波器电路，当泄漏信号发生时，通过与泄漏信号相等频率分量的信号，衰减电路，用于衰减通过滤波电路的信号电平至漏电流 信号和相位反相电路，用于使被衰减的信号的相位反相，使得与泄漏信号的相位相反，从而抵消泄漏信号。

公开(公告)号：US4392016A

公开(公告)日：1983-07-05

申请号：US239914

申请日：1981-03-02

申请人： Don R. Sauer

发明人： Don R. Sauer

IPC分类号： H04H1/00 ,  H04H20/49 ,  H04H5/00

CPC分类号： H04H20/49

摘要： In an AM stereo radio receiver a filter is coupled to the IF amplifier and is tuned to the IF carrier frequency. The filter will ring at the IF and, if desired, can be incorporated into an oscillator circuit. The resulting signal acts as a reinserted carrier that will persist over those intervals during which the carrier would ordinarily be absent due to amplitude overmodulation. In effect the oscillatory signal sets the minimum value to which the carrier can be driven and will act to prevent the noise bursts that ordinarily accompany excessive modulation. Such overmodulation can result from inadvertence at the transmitter or from multipath reception.

摘要翻译： 在AM立体声无线电接收机中，滤波器耦合到IF放大器并被调谐到IF载波频率。 滤波器将在IF处振荡，并且如果需要，可以并入振荡器电路中。 所产生的信号用作重新插入的载波，其将在由于幅度过调制而通常不存在载波的那些间隔处将持续。 实际上，振荡信号设置载波可以被驱动的最小值，并且将起作用以防止通常伴随过度调制的噪声突发。 这种过调制可能由发射机无意识或多径接收引起。

公开(公告)号：US4386235A

公开(公告)日：1983-05-31

申请号：US234962

申请日：1981-02-17

申请人： Michinori Naito

发明人： Michinori Naito

IPC分类号： H03D1/22 ,  H04B1/10 ,  H04H1/00 ,  H04H40/45 ,  H04H40/72 ,  H04H5/00

CPC分类号： H04H40/45 ,  H03D1/2227 ,  H04H40/72

摘要： An FM stereo demodulator comprising a switching signal generator for providing four asymmetrical square wave switching signals whose phase differences from the subcarrier of the FM stereo composite signal are respectively 0.degree., 90.degree., 180.degree., and 270.degree. and whose frequencies are the same as the frequency of the subcarrier; four switching circuits for respectively switching the FM stereo composite signal using the four switching signals; and an undesired-beat cancellation circuit for producing left and right audio signals from the respective output signals of the four switching circuits by cancelling the undesired beat signals in the audio frequency zone, produced by the second harmonic component of the subcarrier and SCA signals contained in the FM stereo composite signals.

摘要翻译： 一种FM立体声解调器，包括一个开关信号发生器，用于提供与FM立体声复合信号的子载波相位差分别为0°，90°，180°和270°的四个非对称方波切换信号，其频率相同 子载波的频率; 四个开关电路，用于使用四个开关信号分别切换FM立体声复合信号; 以及不期望的拍频消除电路，用于通过消除由副载波的二次谐波分量产生的音频频带中的不想要的拍频信号和包含在其中的SCA信号，从四个开关电路的各个输出信号产生左和右音频信号 FM立体声复合信号。

公开(公告)号：US4377728A

公开(公告)日：1983-03-22

申请号：US240445

申请日：1981-03-04

申请人： Francis H. Hilbert

发明人： Francis H. Hilbert

IPC分类号： H03D1/22 ,  H03D3/00 ,  H03L7/08 ,  H03L7/085 ,  H03L7/087 ,  H03L7/10 ,  H04H1/00 ,  H04H20/49 ,  H04H5/00 ,  H03D3/18

CPC分类号： H04H20/49 ,  H03L7/087 ,  H03L7/10

摘要： The circuit determines whether an incoming frequency is within the normal "lock-in" range of a phase locked loop VCO or not, and whether it is higher or lower than the VCO frequency. If not within normal range, the beats are rectified and gated to provide a DC control voltage of the proper value and polarity for locking the oscillator on the incoming frequency. Rectification may be half or full wave as needed, and the circuit may include filter bandwidth control as well. This circuit is suitable for signals of any waveform, quadrature signals, and AM stereophonic signals.

摘要翻译： 电路确定输入频率是否在锁相环VCO的正常“锁定”范围内，以及它是否高于或低于VCO频率。 如果不在正常范围内，则对节拍进行整流和选通，以提供适当值和极性的直流控制电压，以将振荡器锁定在输入频率上。 根据需要，整流可以是一半或全波，并且该电路也可以包括滤波器带宽控制。 该电路适用于任何波形，正交信号和AM立体声信号的信号。

公开(公告)号：US4368354A

公开(公告)日：1983-01-11

申请号：US112815

申请日：1980-01-17

申请人： Makoto Furihata ,  Masanori Oguino ,  Noboru Sakata

发明人： Makoto Furihata ,  Masanori Oguino ,  Noboru Sakata

IPC分类号： H04N5/60 ,  H04H1/00 ,  H04H40/36 ,  H04N7/06 ,  H04H5/00 ,  H04N7/00

CPC分类号： H04H40/36 ,  H04N7/06

摘要： A discriminator apparatus for a television multivoice system comprises a mixer for mixing a program identifying signal with a reference signal thereby to produce a differential beat signal. A reference signal generator includes a signal source of an original frequency, and a frequency converter for converting the original frequency to the reference frequency which is close to the frequency of the program identifying signal and so selected that the frequency of the differential beat signal is lower than the lowest audible frequency. A low-pass filter is employed for extracting the differential beat signal. Need for expensive mechanical filters of a narrow fractional bandwidth is thereby eliminated.

摘要翻译： 一种用于电视多频发音系统的鉴别器装置，包括用于将节目识别信号与参考信号混合从而产生差分拍频信号的混合器。 参考信号发生器包括原始频率的信号源，以及用于将原始频率转换为接近节目识别信号频率的参考频率并被选择为差分差拍信号的频率较低的频率转换器 比最低的可听频率。 采用低通滤波器来提取差分拍频信号。 因此消除了对狭窄分数带宽的昂贵机械滤波器的需求。