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21.发明授权Differential phase reduction circuit for a video demodulating system and method 失效用于视频解调系统的差分相位降低电路及方法
公开(公告)号：US4853641A
公开(公告)日：1989-08-01
申请号：US161555
申请日：1988-02-29
申请人： Michael McGinn
发明人： Michael McGinn
CPC分类号： H04N5/455 , H03D1/2254
摘要： In a stereo television video demodulating system comprising an IF filter coupled via a limiter stage to a phase detector of a phase locked loop and further coupled to a video demodulator, a phase reduction circuit for reducing differential phase effects in the television which includes a capacitive circuit coupled between an output of the video demodulator and the multiplier section of the phase detector and a resistive circuit coupled between an output of the video demodulator and the multiplier section.
摘要翻译： 在包括经由限幅器级耦合到锁相环的相位检测器并进一步耦合到视频解调器的IF滤波器的立体声电视视频解调系统中，用于减少电视中的差分相位效应的相位降低电路包括电容电路 耦合在视频解调器的输出端和相位检测器的乘法器部分之间，以及耦合在视频解调器的输出端和乘法器部分之间的电阻电路。
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公开(公告)号：US4821322A
公开(公告)日：1989-04-11
申请号：US90051
申请日：1987-08-12
申请人： Amar G. Bose
发明人： Amar G. Bose
CPC分类号： H03D1/2209 , H04B1/1646
摘要： Apparatus demodulates frequency-modulated information signals on a radio frequency signal carrying on a suppressed superaudio carrier signal, amplitude-modulated spectral components in a subcarrier channel frequency range above the audio frequency range and frequency modulated spectral components within the audio range. A demodulator demodulates the frequency-modulated information signals to provide detected audio signals having spectral components within the audio frequency range and detected superaudio signals having spectral components including those within the subcarrier channel frequency range above the audio frequency range in response to modulated radiated radio frequency signals arriving at the apparatus over a number of paths of different lengths. There is a reference signal source responsive to the detected superaudio signals that provides a reference signal of the frequency of the suppressed subcarrier characterized by a phase shift substantially the same as that imparted to the detected spectral components within the subcarrier channel frequency range. The reference signal is combined with the detected spectral components within the subcarrier channel frequency range to provide an audio signal.
摘要翻译： 装置对携带抑制超音频载波信号的射频信号，音频频率范围以上的子载波信道频率范围内的幅度调制频谱分量和音频范围内的频率调制频谱分量进行解调。 解调器解调频率调制信息信号，以响应于调制的辐射射频信号，提供具有音频范围内的频谱分量的检测音频信号，并且检测到具有频谱分量的超音频信号，包括在音频频率范围之上的子载波信道频率范围内 通过不同长度的多个路径到达设备。 存在响应于检测到的超音频信号的参考信号源，其提供被抑制的子载波的频率的参考信号，其特征在于与在子载波信道频率范围内被检测的频谱分量相同的相移。 参考信号与子载波信道频率范围内的检测到的频谱分量组合以提供音频信号。
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公开(公告)号：US4816769A
公开(公告)日：1989-03-28
申请号：US3843
申请日：1987-01-16
申请人： John Y. Ma , Louis H. Jandrell
发明人： John Y. Ma , Louis H. Jandrell
CPC分类号： H04B1/16 , H03D1/2254 , H03D2200/0031
摘要： An FM receiver for the reception of digital data modulated on a Subsidiary Communication Authorization (SCA) subcarrier is provided with automatic tuning capability and a coherent demodulator for minimizing noise, distortion and interference. The FM receiver is tuned automatically to minimize the measured amplitude of noise and distortion at the high frequency end of the spectrum of the FM demodulator output, above the frequencies of the SCA signal. The SCA signal is tuned by a heterodyne circuit including a balanced modulator, a voltage-controlled oscillator (VCO), and a bandpass filter. The VCO is automatically tuned to maximize the measured amplitude of the SCA signal selected by the bandpass filter. For coherent detection of BPSK (Binary-Phase-Shift-Keying), the coherent demodulator is preferably and kind of data-aided Costas loop in which digital logic circuits perform phase shifting, phase detecting, a multiplying functions. The feedback of the phase error signal is preferably inhibited whenever the signal-to-noise ratio falls below the level which ensures phase-lock, for example, by inhibiting feedback whenever the amplitude of the filtered in-phase signal in the Costas loop fails to exceed a predetermined threshold level. Preferably the phase error signal is fed back through an integrating low-pass filter to control the VCO of the heterodyne circuit, and is fed back through a bandpass filter to control the oscillator of the Costas loop.
摘要翻译： 用于接收在辅助通信授权（SCA）子载波上调制的数字数据的FM接收机具有自动调谐能力和用于最小化噪声，失真和干扰的相干解调器。 自动调谐FM接收机，以便在FM解调器输出频谱的高频端测得的噪声和失真的振幅最小，高于SCA信号的频率。 SCA信号由包括平衡调制器，压控振荡器（VCO）和带通滤波器的外差电路调谐。 自动调谐VCO以最大化由带通滤波器选择的SCA信号的测量幅度。 对于BPSK（二进制相移键控）的相干检测，相干解调器优选地是数字逻辑电路执行相移，相位检测，乘法函数的数据辅助Costas循环。 当信噪比低于确保相位锁定的电平时，优选地抑制相位误差信号的反馈，例如，只要科斯塔斯环路中滤波的同相信号的幅度失败，通过禁止反馈 超过预定阈值水平。 优选地，相位误差信号通过积分低通滤波器反馈以控制外差电路的VCO，并通过带通滤波器反馈以控制科斯塔斯回路的振荡器。
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公开(公告)号：US4797634A
公开(公告)日：1989-01-10
申请号：US91167
申请日：1987-08-31
申请人： Paul D. Filliman
发明人： Paul D. Filliman
CPC分类号： H03D1/2236
摘要： A controlled crystal oscillator of a stereo decoder of a television receiver using CMOS technology includes first, second and third differential emplifiers that produce corresponding first, second and third pairs of anti-phase output signals. The first and second differential amplifiers have variable gains that vary in opposing manners in accordance with a frequency control signal. The oscillatory signal of a crystal is coupled to corresponding input terminals of the three differential amplifiers such that the phase of the signal that is developed at the input terminal of the third differential amplifier is phase-shifted by approximately 90.degree. relative to those developed at the input terminals of the other two amplifiers. The three pairs of output signals are combined to form a single-ended oscillatory signal that is coupled back to the crystal to complete a regulative feedback path. The frequency of oscillation is determined in accordance with the frequency control signal.
摘要翻译： 使用CMOS技术的电视接收机的立体声解码器的受控晶体振荡器包括产生相应的第一，第二和第三对反相输出信号的第一，第二和第三差分放大器。 第一和第二差分放大器具有根据频率控制信号以相反方式变化的可变增益。 晶体的振荡信号耦合到三个差分放大器的相应输入端，使得在第三差分放大器的输入端产生的信号的相位相对于在第三差分放大器处产生的信号相移大约90度 另外两个放大器的输入端。 三对输出信号被组合以形成耦合回晶体的单端振荡信号以完成调节反馈路径。 振荡频率根据频率控制信号确定。
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公开(公告)号：US4785352A
公开(公告)日：1988-11-15
申请号：US782132
申请日：1985-09-30
CPC分类号： H03D1/2254 , H04N5/52
摘要： A sampled data signal amplitude detector for use in PLL's, for example, includes an absolute value detector to generate the magnitudes of the signal samples to be measured. The magnitudes of pairs of successive samples are compared and the larger magnitude sample of each pair is provided to an averager. The averager, averages a predetermined number of the larger magnitude samples and outputs the average as the amplitude of the applied signal.
摘要翻译： 例如，用于PLL的采样数据信号幅度检测器包括产生要测量的信号样本的幅度的绝对值检测器。 比较连续样本对的大小，并将每对的较大幅度样本提供给平均器。 平均器平均预定数量的较大幅度采样并输出平均值作为施加信号的幅度。
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公开(公告)号：US4782532A
公开(公告)日：1988-11-01
申请号：US38563
申请日：1987-04-15
申请人： Lawrence M. Ecklund
发明人： Lawrence M. Ecklund
CPC分类号： H03J7/10 , H03D1/2236
摘要： An improved radio receiver that maintains a stable predetermined IF frequency upon receipt of input carrier signals of differing frequencies. The IF signal (14) is processed through a signal demodulation unit (16) that includes a tangent processing unit (22) to yield a control signal that varies as a tangent function of both the demodulated IF signal and a reference signal from a reference oscillator (17). This control signal is used to control the frequency and phase of a reference signal (26) used by the IF stage (12) to center the IF signal with respect to the IF stage characteristics.
摘要翻译： 一种改进的无线电接收机，其在接收到不同频率的输入载波信号时保持稳定的预定IF频率。 IF信号（14）通过包括切线处理单元（22）的信号解调单元（16）进行处理，以产生作为解调的IF信号和来自基准振荡器的参考信号的切线函数而变化的控制信号 （17）。 该控制信号用于控制由IF级（12）使用的参考信号（26）的频率和相位，以使IF信号相对于IF级特性居中。
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公开(公告)号：US4712222A
公开(公告)日：1987-12-08
申请号：US745814
申请日：1985-06-17
申请人： Charles M. Heard , Frank C. Yang
发明人： Charles M. Heard , Frank C. Yang
CPC分类号： H04L27/2332 , H03D1/2254 , H03L7/0812 , H03L7/087 , H03D2200/0029 , H03D7/165 , H04L2027/003 , H04L2027/0057
摘要： This invention provides improved performance and reduced cost relative to conventional carrier phase tracking systems. The invention improves the performance of the communication system by rapidly acquiring and reliably tracking the carrier signal with substantially digital hardware. The invention has no reverse slope null characteristic and therefore does not suffer from hangup. As such, acquisition time is independent of phase error. These solutions are provided without the added expense and calibration problems of a crystal filter or the performance compromise of the dual phase detector phase locked loop.The invention includes circuitry which removes the carrier from the received data signal and converts the signal to a complex baseband signal. The baseband signal is subsequently sampled to provide a plurality of complex samples. The phase of each sample is extracted and compared to the phase of an adjacent sample to provide phase difference signals. The phase difference signals are then applied to phase shifting circuitry which substantially compensates for the phase offset in the received data signal.
摘要翻译： 本发明相对于传统的载波相位跟踪系统提供了改进的性能和降低的成本。 本发明通过以基本上数字化的硬件快速获取和可靠地跟踪载波信号来改善通信系统的性能。 本发明没有反向斜率零特性，因此不会出现挂起。 因此，采集时间与相位误差无关。 提供这些解决方案，而不会增加晶体滤波器的费用和校准问题，或双相检测器锁相环的性能损害。 本发明包括从接收的数据信号中去除载波并将该信号转换成复基带信号的电路。 随后采样基带信号以提供多个复杂样本。 提取每个样品的相位并与相邻样品的相位进行比较，以提供相位差信号。 相位差信号然后被施加到基本上补偿接收数据信号中的相位偏移的相移电路。
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公开(公告)号：US4680793A
公开(公告)日：1987-07-14
申请号：US726753
申请日：1985-04-24
申请人： Yoshiro Sugai , Hiroyuki Kimura
发明人： Yoshiro Sugai , Hiroyuki Kimura
CPC分类号： H04H40/54 , H03D1/2236 , H04B1/1676 , H04H40/72 , H04N5/607
摘要： A noise eliminating circuit including a subsignal modulator circuit, a matrix circuit, and sample-and-hold circuits, for reducing signal distortion as well as preventing the in-circuit generation of noise. The sample-and-hold circuits are disposed in the signal paths of a main signal and the demodulated subsignal and are operated by a signal synchronous with a noise component. The holding times of the two sample-and-hold circuits may be made different from one another.
摘要翻译： 一种噪声消除电路，包括子信号调制器电路，矩阵电路和采样保持电路，用于降低信号失真以及防止噪声的电路内产生。 采样和保持电路设置在主信号和解调的次信号的信号路径中，并由与噪声分量同步的信号操作。 两个采样保持电路的保持时间可以彼此不同。
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公开(公告)号：US4651106A
公开(公告)日：1987-03-17
申请号：US824061
申请日：1986-01-30
申请人： Kenji Yokoyama
发明人： Kenji Yokoyama
CPC分类号： H04H40/45 , H03D1/2227 , H04H40/72
摘要： A stereo demodulator capable of demodulating a composite signal without performing a switching operation is disclosed. A subcarrier generating circuit generates a square wave subcarrier signal V1 of 38 KHz which is in turn converted into a triangular wave subcarrier signal V4 of 38 KHz synchronized with the square wave subcarrier signal V1. The composite signal is converted into a current signal i which is then amplified by a voltage-controlled amplifier whose gain varies in accordance with the triangular wave subcarrier signal V4 applied thereto as a control voltage. Since the voltage-controlled amplifier is of such a type that the gain thereof logarithmically varies in accordance with the control voltage, the composite signal is amplified by a gain which varies substantially sinusoidally in accordance with the triangular wave subcarrier signal V4. As an output of the voltage-controlled amplifier is in the form of a pair of currents i.sub.R and i.sub.L which vary complementarily to each other, the signals represent right and left channel signals.
摘要翻译： 公开了能够解调复合信号而不执行切换操作的立体声解调器。 子载波产生电路产生38KHz的方波副载波信号V1，它又与矩形波副载波信号V1同步地转换为38KHz的三角波副载波信号V4。 复合信号被转换成电流信号i，然后电压信号被放大器，放大器的增益根据施加到其上的三角波副载波信号V4作为控制电压而变化。 由于压控放大器的增益按照控制电压对数地变化，因此根据三角波副载波信号V4基本上正弦变化的增益放大合成信号。 由于压控放大器的输出是互补地变化的一对电流iR和iL的形式，所以信号表示右声道和左声道信号。
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公开(公告)号：US4648114A
公开(公告)日：1987-03-03
申请号：US783506
申请日：1985-10-03
申请人： Toshihito Ichikawa
发明人： Toshihito Ichikawa
CPC分类号： H03D1/2236
摘要： An AM stereo demodulator with which the transition from the stereo receiving mode to the monaural receiving mode upon a reduction in the field strength of the received signal is made gradual so as to eliminate an abrupt change in the sound quality. For stereo demodulation, a pair of reference signals are generated which are .pi./2 different in phase for stereo reception. As the field strength of the received signal approaches the level where a phase-locked loop in the demodulator would become unlocked from the carrier of the received signal, the phase difference between the two reference signals is gradually reduced to .pi./4.
摘要翻译： AM立体声解调器在逐渐减小接收信号的场强后，从立体声接收模式向单声道接收模式转换，以消除声音质量的突然变化。 对于立体声解调，产生一对参考信号，其对于立体声接收是相位为π/ 2不同的。 随着接收信号的场强接近解调器中的锁相环将从接收信号的载波解锁的水平，两个参考信号之间的相位差逐渐减小到π/ 4。
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