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公开(公告)号：US09485043B1
公开(公告)日：2016-11-01
申请号：US15164978
申请日：2016-05-26
申请人： Richard Modafferi
发明人： Richard Modafferi
CPC分类号： H04H20/88 , H03C5/00 , H03F3/187 , H03F3/245 , H03F3/45475 , H03F2200/03 , H03F2200/324 , H03F2200/534 , H03F2200/537 , H03F2200/541 , H03F2203/45138 , H03F2203/45526 , H03F2203/45536 , H04H20/49
摘要： A modulation system for AM stereo transmission wherein in a combination of amplitude modulation and phase modulation allows a pair of unique audio channel signals to be modulated onto an AM carrier. When a monophonic audio signal is provided, there is no phase modulation present. However, when a first audio signal (e.g., a “right” channel) differs from a second audio signal (e.g., a “left” audio channel), phase modulation occurs simultaneously with amplitude modulation. The modulation system accepts non-matrixed audio signals and produces quadrature modulation compatible with the industry standard C-QUAM system.
摘要翻译： 用于AM立体声传输的调制系统，其中在幅度调制和相位调制的组合中，允许将一对唯一的音频信道信号调制到AM载波上。 当提供单声道音频信号时，不存在相位调制。 然而，当第一音频信号（例如，“右”声道）与第二音频信号（例如，“左”音频声道）不同时），相位调制与幅度调制同时发生。 调制系统接受非矩阵音频信号，并产生与行业标准C-QUAM系统兼容的正交调制。
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公开(公告)号：US5014316A
公开(公告)日：1991-05-07
申请号：US500837
申请日：1990-03-21
CPC分类号： H04H20/49
摘要： An audio detector circuit forms L+R and L-R audio signals from an intermediate frequency compatible quadrature amplitude modulated signal in the form (1+L+R)cos(fct+.phi.) where .phi. contains phase modulated L+R and L-R signals. An envelope detector generates an L+R audio signal and in-phase and quadrature phase detectors produce L+R and L-R audio signals, respectively. The difference between L+R outputs of the envelope and in-phase detectors are amplified to generate a cosine correction signal. Each detector includes a differential operational amplifier having an field effect feedback transistor coupled between each amplifier output and the corresponding input and an field effect transistor coupling the compatible quadrature amplitude modulated signal to the operational amplifier inputs. The impedances presented by the feedback transistor are varied by the cosine correction signal to remove the cosine component of the compatible quadrature amplitude modulated signal while frequency multiplication at the IF frequency rate provides the correct phase audio signal for matrix and noise processing.
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公开(公告)号：US4688254A
公开(公告)日：1987-08-18
申请号：US846775
申请日：1986-04-01
申请人： Lawrence M. Ecklund
发明人： Lawrence M. Ecklund
CPC分类号： H04H20/49
摘要： A control circuit in an AM stereophonic receiver examines a detected signal for occurrences of overmodulation and, when a first given level of overmodulation is reached, begins to turn down the correction signal used in the demodulation and, if overmodulation continues, would eventually eliminate the correction signal. At a second given level of overmodulation, the circuit will begin to attenuate the stereo difference signal from the receiver output and eventually eliminate it. When the overmodulation is reduced, operating conditions return toward normal.
摘要翻译： AM立体声接收机中的控制电路检查用于出现过调制的检测信号，并且当达到第一给定电平的过调制时，开始降低在解调中使用的校正信号，并且如果继续过调制将最终消除校正 信号。 在第二给定的过调制电平时，电路将开始衰减来自接收器输出的立体声差分信号，并最终消除它。 当过调制减少时，操作条件恢复正常。
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公开(公告)号：US4680795A
公开(公告)日：1987-07-14
申请号：US812687
申请日：1985-12-23
申请人： Lawrence M. Ecklund
发明人： Lawrence M. Ecklund
CPC分类号： H04H20/49 , H03H11/1291
摘要： A variable Q filter network in an AM stereophonic receiver provides elimination of any adjacent channel carrier interference while providing the function of a tone control, either automatic or manually controlled. Parts count and costs, IC pinouts and the possibility of intermodulation are all reduced.
摘要翻译： AM立体声接收机中的可变Q滤波器网络提供消除任何相邻信道载波干扰，同时提供自动或手动控制的音调控制的功能。 零件数量和成本，IC引脚分配和互调的可能性都减少了。
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公开(公告)号：US4653095A
公开(公告)日：1987-03-24
申请号：US826717
申请日：1986-02-06
申请人： Leonard R. Kahn
发明人： Leonard R. Kahn
CPC分类号： H04H20/49
摘要： Certain, but not all AM stereo radio broadcasting and reception systems suffer from a severe form of reception anomaly wherein the perceived stereo image moves from side to side, back and forth, which effect has come to be known as "Stereo Platform Motion" or simply "Platform Motion". A prior art patent proposed a method for sensing reception conditions conductive to Platform Motion and then switching the receiver from stereo to monophonic reception to avoid Platform Motion. The present invention enables the AM stereo receiver to maintain stereo operation under such reception conditions, and instead of switching the receiver to monophonic operation, it switches the receiver to a different method of stereo reception that does not suffer from Platform Motion.
摘要翻译： 某些但不是全部的AM立体声无线电广播和接收系统遭受严重形式的接收异常，其中感知的立体声图像从一侧到另一侧来回移动，这种效果已经被称为“立体声平台运动”或简单地 “平台运动”。 现有技术专利提出了一种用于感测对平台运动传导的接收条件，然后将接收机从立体声切换到单声道接收以避免平台运动的方法。 本发明使AM立体声接收机能够在这种接收条件下保持立体声操作，而不是将接收机切换到单声道操作，它将接收机切换成不受平台运动影响的立体声接收的不同方法。
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公开(公告)号：US4618981A
公开(公告)日：1986-10-21
申请号：US706583
申请日：1985-02-28
申请人： Lawrence M. Ecklund
发明人： Lawrence M. Ecklund
摘要： The tone detector provides accurate detection of a single predetermined tone frequency within a mixture of frequencies, utilizing a carrier signal source at a relatively high frequency. The high frequency signal is divided down to two frequencies, one just above and one just below the tone. The divider output is then maintained at the frequency of the tone by continuously adjusting the divisor number between the two divisor values. Multiplying the received signal or a portion thereof by the divider output provides a detect signal when the tone is present in the received signal with sufficient amplitude.
摘要翻译： 音调检测器利用相对较高频率的载波信号源来提供频率混合内的单个预定音调频率的精确检测。 高频信号被分为两个频率，一个刚刚在上面，一个刚好在音调之下。 然后通过连续调整两个除数值之间的除数，将除法器输出保持在音调的频率。 当接收到的信号或其一部分乘以分频器输出时，当音频以足够的幅度存在于接收信号中时，提供检测信号。
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公开(公告)号：US4580284A
公开(公告)日：1986-04-01
申请号：US621283
申请日：1984-06-15
CPC分类号： H04H20/49
摘要： In an AM stereo system wherein a low frequency pilot tone is added to the difference channel signal before modulation of the carrier, "image shifting" and audio distortion in a receiver, due to residual pilot tone signal, are removed by separating out a portion of the pilot tone after it has been filtered and phase shifed for enabling the stereo mode of operation. The separated signal is then inverted and delayed appropriately for each of the PLL and audio circuits.
摘要翻译： 在AM调制立体声系统中，其中在调制载波之前将低频导频信号加到差分信道信号上，由于残余导频音信号，接收机中的“图像移位”和音频失真被分离出一部分 经过滤波和相位移后的导频音使得立体声操作模式成为可能。 然后对于每个PLL和音频电路，分离的信号被反相和适当地延迟。
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公开(公告)号：US4536885A
公开(公告)日：1985-08-20
申请号：US565303
申请日：1983-12-27
申请人： Bernard D. Loughlin
发明人： Bernard D. Loughlin
CPC分类号： H04H20/49 , H03G3/3073
摘要： In a receiver for composite amplitude and angle modulated signals and having a non-flat automatic gain control characteristic, there is provided apparatus for providing distortion correction to the quadrature component produced by the angular modulation in accordance with the amplitude modulation component. In accordance with the invention, the output of an amplitude demodulator is modified to remove the carrier signal level dependent magnitude multiplier and develop a modification signal which is used to inversely amplitude modulate the quadrature signal component to provide distortion correction over a range of carrier signal levels. Such inverse modulation can be provided before or after quadrature demodulation of the received signal.
摘要翻译： 在用于复合幅度和角度调制信号并且具有非平坦自动增益控制特性的接收机中，提供了用于根据调幅分量为由角度调制产生的正交分量提供失真校正的装置。 根据本发明，修改幅度解调器的输出以去除载波信号电平相关幅度乘法器并产生修正信号，该修改信号用于对正交信号分量进行逆幅度调制，以在载波信号电平范围内提供失真校正 。 可以在接收信号的正交解调之前或之后提供这种逆调制。
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公开(公告)号：US4510614A
公开(公告)日：1985-04-09
申请号：US577686
申请日：1984-02-07
CPC分类号： H04H20/49
摘要： A method for generating a compatible AM quadrature stereo wave by delivering a modulated carrier with in-phase sidebands generated by a first combination of two signals, and quadrature sidebands generated by a second combination of the signals, the in-phase and quadrature sidebands having substantially the same maximum amplitude. The carrier and both sets of sidebands are delivered to an envelope detector, which delivers only the first combination of signals, undistorted by the presence of the quadrature sidebands. The carrier and both sets of sidebands are also delivered to a synchronous detector, which delivers only the first combination of signals with predistortion. The output of the synchronous detector is subtracted from the output of the envelope detector to obtain as a result the predistortion of the first signal combination due to the presence of the quadrature sidebands. The distortion is then passed through a filter with the pass-band of the signal frequency band, and an equalizer, which adjusts delay so that negative feedback occurs across a wide frequency band, in accordance with well-known theory. The output of the equalizer is delivered to the modulator for the first combination of signals, so that the transmitter delivers carrier, in-band predistorted sidebands, and quadrature sidebands, which are demodulated by the envelope detector of a receiver as the first combination of signals, free from distortion.
摘要翻译： 一种用于通过传送由两个信号的第一组合产生的同相边带的调制载波和由信号的第二组合产生的正交边带来产生兼容的AM正交立体声波的方法，所述同相和正交边带具有基本上 相同的最大幅度。 载波和两组边带被传送到包络检测器，其仅传送信号的第一组合，通过正交边带的存在而不失真。 载波和两组边带也被传送到同步检测器，该同步检测器仅传递具有预失真的信号的第一组合。 从包络检测器的输出中减去同步检测器的输出，从而获得由于存在正交边带而导致的第一信号组合的预失真。 然后，按照众所周知的理论，使失真通过具有信号频带的通带的滤波器和均衡器，该均衡器调整延迟，使得跨越宽频带发生负反馈。 均衡器的输出被递送到用于信号的第一组合的调制器，使得发射机递送载波，带内预失真边带和正交边带，其由接收机的包络检测器解调为信号的第一组合 ，没有扭曲。
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公开(公告)号：US4486898A
公开(公告)日：1984-12-04
申请号：US416327
申请日：1982-09-09
申请人： Satoshi Yokoya
发明人： Satoshi Yokoya
CPC分类号： H04H20/49
摘要： An amplitude limiter for an AM broadcast transmitter to minimize energy in the broadcasted signal outside an allocated broadcast bandwidth. The secondary and higher order spectra (i.e. second and higher harmonics) of a broadcasted AM stereophonic signal are minimized by limiting the amplitude of the audio signal, prior to modulation onto the carrier, within a predetermined portion of the audio frequency range. This is achieved by controlling the gain of the audio signals in that predetermined portion as a function of the level of a submodulation component also within that predetermined portion of the audio frequency range.
摘要翻译： 用于AM广播发射机的限幅器，用于最小化在所分配的广播带宽之外的广播信号中的能量。 广播的AM立体声信号的次级和高阶频谱（即第二和更高次谐波）通过在音频频率范围的预定部分内调制到载波之前将音频信号的幅度限制在最小。 这是通过在该预定部分中的音频信号的增益作为也在音频范围的该预定部分内的子调制分量的电平的函数来实现的。
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