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公开(公告)号：US20210203276A1
公开(公告)日：2021-07-01
申请号：US17123575
申请日：2020-12-16
申请人： Littelfuse, Inc.
发明人： Eric D. Blom
摘要： A self-oscillating spread spectrum frequency control loop contains a gated voltage-controlled oscillator (VCO) which receives a digital signal that can start or stop its oscillation. The VCO generates a spread spectrum carrier by receiving a triangle wave signal from a delaying ramp generator in a loop, its ramp direction controlled by a frequency comparator. The loop generates a spectrum spread as wide as possible above a minimum frequency. RF isolators that utilize low-pass filters in the transmitter and high-pass filters in the receiver, where the F-3 dB cutoff frequencies of both filters vary in a correlated manner, are used to not produce spread spectrum frequencies below the minimum frequency. Die from a given wafer lot, when designed such that the low- and high-pass cutoff frequencies track, can be used to form RF digital isolators whose minimum spread spectrum frequency does not go below the minimum frequency required by that wafer lot.
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公开(公告)号：US10938393B2
公开(公告)日：2021-03-02
申请号：US16709604
申请日：2019-12-10
摘要： An oscillator is configured to generate a signal with a frequency sweep, the oscillator having circuitry comprising a set of capacitors, each capacitor of the set of capacitors being switchably connectable in parallel in the circuitry so that the frequency of the signal has an intrinsic dependence on the number of the capacitors connected, a shift register controllable by a clock line and comprising a number of bits, each bit of the number of bits controlling connection of a respective capacitor of the set of capacitors so that the capacitors are connectable or disconnectable in a pre-determined order by shifting, respectively, activation or de-activation bits into the shift register, wherein the shifting is paced by the clock line; and a clock signal generator configured to output a clock signal with a time modulation on the clock line.
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公开(公告)号：US09226350B2
公开(公告)日：2015-12-29
申请号：US14159493
申请日：2014-01-21
申请人： Rohm Co., Ltd.
发明人： Koji Katsura
CPC分类号： H05B33/0815 , B60Q1/0094 , B60Q11/005 , H02M3/156 , H03B23/00 , H03K4/06 , H05B33/0818 , H05B33/0887 , H05B33/089
摘要： An oscillation circuit includes: a ramp voltage generating unit configured to generate a ramp voltage; and a clock signal generating unit configured to generate a clock signal. The clock signal generating unit includes: a bias unit configured to apply one of the ramp voltage and a fixed voltage, as a bias voltage, to a resistor; and an oscillator configured to determine an oscillation frequency of the clock signal in response to a bias current flowing through the resistor.
摘要翻译： 振荡电路包括：斜坡电压产生单元，被配置为产生斜坡电压; 以及时钟信号生成单元，被配置为生成时钟信号。 时钟信号发生单元包括：偏置单元，被配置为将斜坡电压和固定电压中的一个作为偏置电压施加到电阻器; 以及振荡器，被配置为响应于流过所述电阻器的偏置电流来确定所述时钟信号的振荡频率。
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4.发明授权Frequency sweep signal generator, frequency component analysis apparatus, radio apparatus, and frequency sweep signal generating method 有权频率扫描信号发生器，频率分量分析装置，无线电装置和频率扫描信号产生方法公开(公告)号：US09143313B2
公开(公告)日：2015-09-22
申请号：US14239525
申请日：2012-06-12
申请人： Masaki Kitsunezuka
发明人： Masaki Kitsunezuka
CPC分类号： H04L7/033 , H03B5/1215 , H03B5/1228 , H03B5/1243 , H03B23/00 , H03B2200/0092 , H03J1/0091 , H03J2200/10 , H03L7/0891 , H03L7/0893 , H03L7/091 , H03L7/099 , H03L7/18 , H03L2207/05
摘要： A frequency sweep signal generator in which the frequency error is small even when the control values and the oscillating frequencies have a non-linear relation. The frequency sweep signal generator includes a variable frequency oscillator that changes an oscillating frequency according to a change of an input control value, and a first controller that generates a first control value so that the oscillating frequency within a predetermined frequency sweeping range is output. The first controller controls an increment of the first control value to be output to the variable frequency oscillator per unit time so that, when a change of the oscillating frequency with respect to the increment of the first control value is non-linear, the oscillating frequency is changed linearly with respect to a passage of time.
摘要翻译： 即使当控制值和振荡频率具有非线性关系时，频率误差也小的频率扫描信号发生器。 频率扫描信号发生器包括：可变频率振荡器，其根据输入控制值的变化而改变振荡频率;以及第一控制器，其产生第一控制值，使得输出在预定频率扫描范围内的振荡频率。 第一控制器控制每单位时间输出到可变频率振荡器的第一控制值的增量，使得当振荡频率相对于第一控制值的增量的变化是非线性的时，振荡频率 相对于时间的推移线性地改变。
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公开(公告)号：US20090174440A1
公开(公告)日：2009-07-09
申请号：US12346069
申请日：2008-12-30
IPC分类号： H03B23/00
CPC分类号： H02M1/44 , H02M3/156 , H02M2001/0032 , Y02B70/16
摘要： A frequency-hopping pulse-width modulator is disclosed, which facilitates a switching regulator to use smaller-size inductive and capacitive elements, to have an improved power efficiency at light load, as well as predictable spectrum at different load levels. The improved modulator automatically determines the switching frequency of a switching regulator according to the load current delivered by the switching regulator from a number of pre-defined frequencies, which are all multiples of a fundamental frequency. By designing the maximum switching frequency of frequency-hopping pulse-width modulator in the MHz range, a switching regulator is able to use smaller-size inductive and capacitive elements. Light-load efficiency of the switching regulator with the frequency-hopping pulse-width modulator is also greatly improved as switching frequency of such switching regulator is reduced with decreased load current. More importantly, spectrum of a switching regulator with the frequency-hopping pulse-width modulator is as predictable as spectrum of a switching regulator with a conventional pulse-width modulator operated at the fundamental frequency.
摘要翻译： 公开了一种跳频脉冲宽度调制器，其有助于开关调节器使用较小尺寸的电感和电容元件，以在轻负载下具有改进的功率效率，以及在不同负载水平下具有可预测的频谱。 改进的调制器根据开关稳压器从多个预定频率（其基本频率的倍数）输出的负载电流自动确定开关稳压器的开关频率。 通过在MHz范围内设计跳频脉宽调制器的最大开关频率，开关稳压器能够使用较小尺寸的电感和电容元件。 具有跳频脉宽调制器的开关稳压器的轻负载效率也大大提高，因为这种开关调节器的开关频率随着负载电流的减小而减小。 更重要的是，具有跳频脉冲宽度调制器的开关稳压器的频谱与具有在基频操作的常规脉宽调制器的开关调节器的频谱一样可预测。
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公开(公告)号：USH1797H
公开(公告)日：1999-07-06
申请号：US553902
申请日：1983-11-21
摘要： Linear frequency modulation having a large time-bandwidth product and an remely linear frequency versus time waveform, is provided by a feedback technique utilizing a linear ramp voltage generator whose output is summed with a correction voltage to drive a voltage controlled oscillator to output the LFM waveform. Part of the LFM waveform is fed back through a digital discriminator for error signal generation and comparison with a preset value associated with the output slope linearity, thus yielding the basis for generating the correction voltage.
摘要翻译： 通过使用线性斜坡电压发生器的反馈技术提供具有大时间带宽乘积和非常线性的频率对时间波形的线性频率调制器，其输出与校正电压相加以驱动压控振荡器以输出LFM波形 。 部分LFM波形通过数字鉴频器反馈，用于产生误差信号并与与输出斜率线性度相关的预设值进行比较，从而产生校正电压的基础。
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7.发明授权
公开(公告)号：US5777574A
公开(公告)日：1998-07-07
申请号：US769091
申请日：1996-12-18
申请人： John P. Robinson
发明人： John P. Robinson
CPC分类号： H03B23/00 , G01S13/90 , G01S7/282 , H03B21/02 , G01S13/282 , H03B2200/0092 , H03B28/00
摘要： An apparatus and method of linear frequency modulation waveform bandwidth multiplication including a digital linear frequency modulation waveform synthesizer for generating a synthesized waveform having an upchirp component of linearly varying frequency during a first half signal duration of the synthesized waveform followed by a downchirp component having linearly varying frequency during a second half of the signal duration of the synthesized waveform. The synthesized waveform is upconverted and subsequently bandpass filtered to provide a filtered waveform to a mixer for mixing with local oscillation signals. The upchirp and downchirp components of the filtered waveform are respectively mixed by first and second local oscillation signals having respective first and second oscillation frequencies in the mixer. The local oscillation signal frequencies have a predetermined relationship to ensure that the signal components of the output signal corresponding to the upchirp and downchirp components transition smoothly. The corresponding linear frequency modulation bandwidth multiplied signal has decreased nonlinearities.
摘要翻译： 一种线性频率调制波形带宽乘法的装置和方法，包括数字线性频率调制波形合成器，用于在合成波形的第一半信号持续时间内产生具有线性变化频率的上升频率的合成波形，随后是具有线性变化的向下线分量 在合成波形的信号持续时间的后半段的频率。 合成的波形被上变频，随后进行带通滤波，以将滤波后的波形提供给混频器以与本地振荡信号混合。 滤波后的波形的upchirp和downchirp分量在混频器中分别由具有相应的第一和第二振荡频率的第一和第二本地振荡信号混合。 本地振荡信号频率具有预定的关系，以确保对应于upchirp和downchirp分量的输出信号的信号分量平滑地转变。 相应的线性频率调制带宽相乘信号具有降低的非线性。
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公开(公告)号：US5347176A
公开(公告)日：1994-09-13
申请号：US18948
申请日：1993-02-17
申请人： Alan R. Bloom
发明人： Alan R. Bloom
CPC分类号： H03L7/00 , G01R31/2841 , H03K4/026 , H03K4/90
摘要： An analog ramp signal is used to control the frequency of a swept radio-frequency (RF) test oscillator. The analog ramp signal is generated by applying a fixed reference voltage to an analog integrator circuit. However, ramp accuracy is degraded by integrator gain error, drift, and nonlinearity. To correct for these errors, the analog ramp signal is periodically compared to a digital ramp signal generated by a digital-to-analog converter (DAC) during the course of a sweep. Preferably, the analog ramp signal is compared to the digital ramp signal many times during the course of the sweep. The difference between the two ramp signals is scaled and combined with the reference voltage to correct the slope of the analog ramp signal. An additional DAC preferably adjusts the gain of the feedback loop.
摘要翻译： 模拟斜坡信号用于控制扫频射频（RF）测试振荡器的频率。 通过向模拟积分电路施加固定的参考电压来产生模拟斜坡信号。 然而，积分器增益误差，漂移和非线性降低了斜坡精度。 为了纠正这些误差，模拟斜坡信号在扫描过程中与数模转换器（DAC）产生的数字斜坡信号周期性地进行比较。 优选地，在扫描过程中将模拟斜坡信号与数字斜坡信号进行多次比较。 两个斜坡信号之间的差异被缩放并与参考电压组合以校正模拟斜坡信号的斜率。 附加DAC优选地调整反馈回路的增益。
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公开(公告)号：US5172123A
公开(公告)日：1992-12-15
申请号：US696236
申请日：1985-01-29
申请人： Richard W. Johnson
发明人： Richard W. Johnson
CPC分类号： H03B23/00 , G01S13/343 , G01S7/4008 , H03C3/08 , H03C2200/0029 , H03C2200/0079
摘要： Range resolution in an FMCW radar system is achieved by providing a periodic linear frequency sweep. The present invention assures the linearity of this sweep by using a negative feedback circuit which includes means for obtaining 16 sequential instantaneous frequency versus time slope measurements during each sweep cycle, generating a set of 16 sequential error signals and a corresponding set of correction voltages, and applying these correction voltages to the sweep drive voltage used to drive the voltage controlled oscillator that generates the frequency swept output signal.
摘要翻译： 通过提供周期性线性频率扫描来实现FMCW雷达系统中的范围分辨率。 本发明通过使用负反馈电路确保该扫描的线性，该负反馈电路包括用于在每个扫描周期期间获得16个顺序瞬时频率对时间斜率测量的装置，产生一组16个顺序误差信号和相应的一组校正电压，以及 将这些校正电压施加到用于驱动产生频率扫描输出信号的压控振荡器的扫描驱动电压。
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10.发明授权Phase-locking circuit for swept synthesized source preferably having stability enhancement circuit 失效用于扫描合成源的锁相电路优选具有稳定性增强电路
公开(公告)号：US5130670A
公开(公告)日：1992-07-14
申请号：US739592
申请日：1991-08-01
申请人： Stanley E. Jaffe
发明人： Stanley E. Jaffe
IPC分类号： H03B1/00 , H03B23/00 , H03C3/09 , H03C3/18 , H03J7/18 , H03L7/10 , H03L7/12 , H03L7/18 , H03L7/183 , H03L7/20
CPC分类号： H03B23/00 , H03L7/12 , H03L7/183 , H03L7/20 , H03B2200/0092 , H03B2201/0241 , H03C3/0908 , H03C3/18
摘要： A phase-lock loop for a swept synthesized source in which hysteresis, tuning nonlinearity, and drift over time and temperature of an oscillator incorporated into the swept synthesized source are compensated. The tuning current to the oscillator is initialized to zero to eliminate hysteresis effects. Then, the pretune current is set to produce the minimum operating frequency of the oscillator. Next, the main phase-lock loop is closed, and a low-frequency synthesizer is swept to in turn sweep the oscillator over a selected frequency span. If the selected frequency span extends over other frequency bands, the oscillator is swept to the maximum frequency of the present band and held at this frequency by a track and hold circuit. The main phase-lock loop is opened, the low-frequency synthesizer is re-initialized, the main phase-lock loop is again closed, and the low-frequency synthesizer is swept again. Each frequency band is crossed in a similar manner until the selected frequency span is swept. In order to improve phase-noise and transient response performance of the low-frequency synthesizer, a phase-lock loop speed-up and stability enhancement circuit comprising a zener diode connected across a passive lag-lead network is incorporated. Pretune calibration for the swept synthesized source is also provided.
摘要翻译： 用于扫描合成源的锁相环，其中补偿了并入到扫描合成源中的振荡器的滞后，调谐非线性以及随时间和温度的漂移。 振荡器的调谐电流初始化为零以消除滞后效应。 然后，预调电流被设置为产生振荡器的最小工作频率。 接下来，主锁相环闭合，并且将低频合成器扫过，从而在选定的频率跨度上扫描振荡器。 如果所选择的频率跨度超过其他频带，则将振荡器扫描到当前频带的最大频率，并通过跟踪和保持电路保持在该频率。 主锁相环打开，低频合成器重新初始化，主相锁闭环再次闭合，低频合成器再次扫频。 每个频带以相似的方式交叉，直到选定的频率跨度被扫描为止。 为了提高低频合成器的相位噪声和瞬态响应性能，包括一个锁相环加速和稳定性增强电路，其包括连接在被动滞后引线网络上的齐纳二极管。 还提供了扫描合成源的预调整校准。
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