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1.发明授权Apparatus and method for DC offset compensation in a direct conversion receiver 有权直接转换接收机中DC偏移补偿的装置和方法公开(公告)号：US07319852B2
公开(公告)日：2008-01-15
申请号：US10233364
申请日：2002-08-29
IPC分类号： H04B1/26
CPC分类号： H04L25/063 , H03D3/008 , H04B1/30
摘要： An apparatus for coarse compensation of a direct current (DC) offset in a direct to baseband receiver architecture utilizes a serial analog to digital converter (ADC), such as a Delta-Sigma converter, to convert the received signal to digital form. The output of the ADC is sampled for a predetermined number of samples and a counter coupled to the ADC is incremented each time the sample generated by the ADC is a logic one. The counter is not incremented if the sample from the ADC is a logic zero. After the predetermined number of samples is obtained, the counter value is indicative of the DC offset in the received signal. The counter value may be converted by a code converter to a correction value for easy operation of a digital to analog converter (DAC). If the number of samples from the ADC is a power of two, the code converted may be readily implemented by simply inverting the most significant bit (MSB) from the counter to thereby generate a twos complement version of the counter value. The correction value is coupled to the DAC to generate a compensation signal, which is provided to the received signal path in the form of a feedback signal to compensate for the DC offset.
摘要翻译： 用于直接到基带接收机架构中的直流（DC）偏移的粗略补偿的装置利用诸如Δ-Σ转换器的串行模数转换器（ADC）将接收的信号转换成数字形式。 对于预定数量的采样，ADC的输出被采样，并且每当由ADC产生的采样为逻辑1时，耦合到ADC的计数器递增。 如果来自ADC的采样为逻辑0，则计数器不递增。 在获得预定数量的样本之后，计数器值表示接收信号中的直流偏移。 计数器值可以由代码转换器转换成用于容易操作数模转换器（DAC）的校正值。 如果来自ADC的采样数是2的幂，则通过简单地将来自计数器的最高有效位（MSB）反相，从而生成计数器值的二进制补码版本，可以容易地实现转换代码。 校正值耦合到DAC以产生补偿信号，其以反馈信号的形式提供给接收信号路径以补偿DC偏移。
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公开(公告)号：US06184844B2
公开(公告)日：2001-02-06
申请号：US08826289
申请日：1997-03-27
IPC分类号： H01Q136
摘要： A dual-band helical antenna provides operation in two frequency bands. The dual-band helical antenna includes two single-band antennas, each having a feed network, a ground plane opposite the feed network, and a set of one or more radiators extending from feed network. According to one aspect of the invention, a tab extends from the feed network of one of the antennas which provides a feed for that antenna. The tab also provides a path for current to flow from the radiators of the second antenna along the axis of the second antenna to thereby increase the energy radiated in the directions perpendicular to the axis. According to another feature of the invention, the ground plane of one antenna is used as a shorting ring for the other antenna.
摘要翻译： 双频螺旋天线提供两个频带的操作。 双频带螺旋天线包括两个单频带天线，每个具有馈电网络，与馈电网络相对的接地平面以及从馈电网络延伸的一组或多个辐射器组。 根据本发明的一个方面，突片从天线之一的馈电网络延伸，其提供用于该天线的馈电。 该突片还提供了一个用于电流从第二天线的辐射器沿第二天线的轴流动的路径，从而增加沿垂直于该轴线的方向辐射的能量。 根据本发明的另一个特征，一个天线的接地平面用作另一个天线的短路环。
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公开(公告)号：US20070189419A1
公开(公告)日：2007-08-16
申请号：US11352495
申请日：2006-02-10
申请人： Daniel Filipovic
发明人： Daniel Filipovic
摘要： A multiple analog signal converter (100) simultaneously converts multiple analog signals (104,106) to digital signals (112, 114) using a single analog to digital converter (ADC) 102. A first analog signal (104) at a first center frequency and a second analog signal (106) at a second center frequency are processed by the ADC (102) to generate a composite digital signal (110) comprising a first digital signal (112) corresponding to the first analog signal (104) and a second digital signal (114) corresponding to the second analog signal (106). The composite digital signal (110) is digitally frequency shifted to recover the second digital signal (106). The first digital signal (104) is recovered by digitally filtering the composite digital signal (110). In some circumstances, a first radio frequency (RF) signal (118) and a second RF signal (122) are frequency shifted to generate the first analog signal (104) and second analog signal (106).
摘要翻译： 多模拟信号转换器（100）使用单个模数转换器（ADC）102同时转换多个模拟信号（104,106）到数字信号（112,114）。 第一中心频率的第一模拟信号（104）和第二中心频率的第二模拟信号（106）由ADC（102）处理以产生包括第一数字信号（112）的复合数字信号（110） 对应于第一模拟信号（104）和对应于第二模拟信号（106）的第二数字信号（114）。 复合数字信号（110）被数字频移以恢复第二数字信号（106）。 通过数字滤波复合数字信号（110）来恢复第一数字信号（104）。 在某些情况下，第一射频（RF）信号（118）和第二RF信号（122）被频移以产生第一模拟信号（104）和第二模拟信号（106）。
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公开(公告)号：US20070153878A1
公开(公告)日：2007-07-05
申请号：US11324858
申请日：2006-01-04
申请人： Daniel Filipovic
发明人： Daniel Filipovic
CPC分类号： H04B1/1036 , H04B1/707 , H04B1/7101 , H04L27/2647
摘要： Techniques for suppressing spurs in a receiver are described. A processor (e.g., within a wireless device) receives digital samples for a desired signal having a spur located within the bandwidth of the desired signal. A spur is an undesired signal that may be generated internally at the receiver or may come from an external interfering source. The processor filters the digital samples to suppress the spur and provides output samples having the spur suppressed. The processor may detect for the spur, e.g., by performing an FFT on the digital samples and examining the spectral response. The processor may filter the digital samples with a notch filter having an adjustable notch frequency and/or an adjustable notch bandwidth. For example, the notch frequency may be set based on the frequency of the spur, and the notch bandwidth may be set based on the amplitude of the spur.
摘要翻译： 描述了用于抑制接收机中的杂散的技术。 处理器（例如，在无线设备内）接收用于期望信号的数字样本，该期望信号具有位于期望信号的带宽内的杂音。 杂散是可能在接收器内部产生或可能来自外部干扰源的不希望的信号。 处理器对数字采样进行滤波以抑制杂散，并提供抑制杂散的输出样本。 处理器可以例如通过对数字样本执行FFT并检查光谱响应来检测杂散。 处理器可以用具有可调节陷波频率和/或可调陷波带宽的陷波滤波器对数字样本进行滤波。 例如，可以基于支线的频率设置陷波频率，并且可以基于支线的幅度来设置陷波带宽。
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公开(公告)号：US20050130687A1
公开(公告)日：2005-06-16
申请号：US10412928
申请日：2003-04-11
申请人： Daniel Filipovic , Clark Korb
发明人： Daniel Filipovic , Clark Korb
CPC分类号： H04B7/005
摘要： A wireless device configured to support a wireless networking protocol may utilize signal processing techniques that can mitigate the effects of jammer signals. For example, when a measured power associated with a digital sample of a received wireless signal is greater than a threshold, the wireless device may determine if the wireless signal corresponds to a wireless networking packet to be demodulated. If the wireless signal does not correspond to a wireless networking packet to be demodulated, the wireless device may adjust the threshold so that the power associated with the digital sample is less than the threshold. In other words, if the signal is a jammer signal, the wireless device may adjust its noise floor upward so that continuous reception of the same jammer signal does not trigger demodulation a second time.
摘要翻译： 被配置为支持无线网络协议的无线设备可以利用可以减轻干扰信号的影响的信号处理技术。 例如，当与所接收的无线信号的数字样本相关联的测量功率大于阈值时，无线设备可以确定无线信号是否对应于待解调的无线网络分组。 如果无线信号不对应于待解调的无线网络分组，则无线设备可以调整阈值，使得与数字样本相关联的功率小于阈值。 换句话说，如果信号是干扰信号，则无线设备可以向上调整其本底噪声，使得相同干扰信号的连续接收不会再次触发解调。
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公开(公告)号：US06278414B1
公开(公告)日：2001-08-21
申请号：US08690023
申请日：1996-07-31
申请人： Daniel Filipovic
发明人： Daniel Filipovic
IPC分类号： H01Q136
摘要： A bent-segment helical antenna utilizes one or more radiators wrapped in a helical fashion. The radiators are comprised of a plurality of segments. A first segment extends from a feed network at a first end of a radiator portion of the antenna toward a second end of the radiator portion. A second segment is adjacent to and offset from the first segment. A third segment connects the first and second segments at the second end of the radiator portion.
摘要翻译： 弯曲段螺旋天线利用以螺旋方式包裹的一个或多个辐射器。 散热器由多个段组成。 第一段从天线的散热器部分的第一端处的馈电网延伸到散热器部分的第二端。 第二段与第一段相邻并偏移。 第三段在散热器部分的第二端连接第一和第二段。
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公开(公告)号：US5990847A
公开(公告)日：1999-11-23
申请号：US640298
申请日：1996-04-30
申请人： Daniel Filipovic , Ali Tassoudji
发明人： Daniel Filipovic , Ali Tassoudji
CPC分类号： H01Q11/08
摘要： A coupled multi-segment helical antenna is provided having a length that is shorter than otherwise obtainable for a conventional half-wavelength antenna. The coupled multi-segment helical antenna includes radiator portion having a plurality of helically wound radiators extending from one end of the radiator portion to the other end of the radiator portion. Each radiator is made up of a set of two or more segments. A first segment extends in a helical fashion from the first end of the radiator portion toward the second end of the radiator portion. The second segment extends in a helical fashion from the second end of the radiator portion toward the first end of the radiator portion, wherein a portion of the first radiator segment is in proximity with a portion of the second radiator segment such that the first and second radiator segments are electromagnetically coupled to one another.
摘要翻译： 提供耦合的多段螺旋天线，其长度比传统的半波长天线可获得的长度短。 耦合的多段螺旋天线包括散热器部分，其具有从散热器部分的一端延伸到散热器部分的另一端的多个螺旋缠绕的辐射器。 每个散热器由两个或更多个部分组成。 第一段从辐射器部分的第一端朝向散热器部分的第二端呈螺旋形延伸。 第二段从辐射器部分的第二端朝向散热器部分的第一端以螺旋方式延伸，其中第一辐射器段的一部分与第二散热器段的一部分接近，使得第一和第二 散热器段彼此电磁耦合。
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公开(公告)号：US5910752A
公开(公告)日：1999-06-08
申请号：US987307
申请日：1997-12-09
申请人： Daniel Filipovic , Saed G. Younis
发明人： Daniel Filipovic , Saed G. Younis
CPC分类号： H03D3/006 , H03D2200/005 , H03D2200/0056 , H03D2200/0062 , H03D2200/0064
摘要： An receiver receives, amplifies, filters, and downconverts an RF signal to obtain an FM signal. The FM signal is then limited by a limiter and sampled by an ADC. The FM samples from the ADC are provided to an edge detector which detects transitions in the FM samples. The transitions correspond to zero crossings in the FM signal. The time period between the zero crossings, or the cycle width, is measured with a counter to determine the instantaneous frequency f.sub.c of the FM signal. The demodulated output is proportional to the instantaneous frequency which can be determined from the measured cycle periods as f.sub.c =1/2T.sub.c, f.sub.c .apprxeq.-.alpha.T.sub.c, or f.sub.c .varies.T.sub.c, where T.sub.c is the measured cycle period, and .alpha. is a constant based on the slope of 1/2T.sub.c,avg, where T.sub.c,avg is the average cycle period. The sample rate of the demodulated output can be reduced, through resampling, to minimize power consumption in the subsequent signal processing blocks.
摘要翻译： 接收机接收，放大，滤波和下变频RF信号以获得FM信号。 然后，FM信号由限幅器限制并由ADC采样。 来自ADC的FM采样被提供给检测FM样本中的转变的边缘检测器。 转换对应于FM信号中的过零点。 通过计数器测量过零点之间的时间周期或周期宽度，以确定FM信号的瞬时频率fc。 解调输出与瞬时频率成比例，可以从测量的周期周期确定为fc = + E，fra 1/2 + EE Tc，fc APPROX-αTc或fc比例Tc，其中Tc是测量周期周期 ，α是基于+ E的斜率的常数，f1 / 2 + EE Tc，avg，其中Tc，avg是平均循环周期。 可以通过重采样来减小解调输出的采样率，以使后续信号处理模块中的功耗最小化。
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公开(公告)号：US08134413B2
公开(公告)日：2012-03-13
申请号：US12606357
申请日：2009-10-27
申请人： Daniel Filipovic , Hongbo Yan
发明人： Daniel Filipovic , Hongbo Yan
IPC分类号： H03L7/00
CPC分类号： H03L1/027 , G04G3/022 , H03K23/42 , H03K23/662 , H03K23/68
摘要： Techniques for synthesizing a signal having a desired frequency from an oscillation signal. In an aspect, a reference signal having a known frequency may be periodically used to determine a ratio between the desired frequency and the frequency of the oscillation signal. The oscillation signal may be decimated by the ratio to generate a synthesized signal having approximately the desired frequency. In an aspect, the decimation may be performed by generating a pulse in response to the output of an accumulator that accumulates in steps of the ratio. To save power, the oscillation signal may be derived from a low-power oscillator, while the reference signal may be turned on only during periodic calibration. Further aspects for improving the frequency accuracy of the synthesized signal are disclosed.
摘要翻译： 用于从振荡信号合成具有期望频率的信号的技术。 在一方面，可以周期性地使用具有已知频率的参考信号来确定期望频率与振荡信号的频率之间的比率。 振荡信号可以通过该比率被抽取，以产生具有大致期望频率的合成信号。 在一个方面，可以通过响应于以比例的步长积累的累加器的输出产生脉冲来执行抽取。 为了节省电力，振荡信号可以从低功率振荡器导出，而参考信号可以仅在周期性校准期间被导通。 公开了用于提高合成信号的频率精度的其它方面。
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公开(公告)号：US20110095791A1
公开(公告)日：2011-04-28
申请号：US12606357
申请日：2009-10-27
申请人： Daniel Filipovic , Hongbo Yan
发明人： Daniel Filipovic , Hongbo Yan
IPC分类号： H03B21/00
CPC分类号： H03L1/027 , G04G3/022 , H03K23/42 , H03K23/662 , H03K23/68
摘要： Techniques for synthesizing a signal having a desired frequency from an oscillation signal. In an aspect, a reference signal having a known frequency may be periodically used to determine a ratio between the desired frequency and the frequency of the oscillation signal. The oscillation signal may be decimated by the ratio to generate a synthesized signal having approximately the desired frequency. In an aspect, the decimation may be performed by generating a pulse in response to the output of an accumulator that accumulates in steps of the ratio. To save power, the oscillation signal may be derived from a low-power oscillator, while the reference signal may be turned on only during periodic calibration. Further aspects for improving the frequency accuracy of the synthesized signal are disclosed.
摘要翻译： 用于从振荡信号合成具有期望频率的信号的技术。 在一方面，可以周期性地使用具有已知频率的参考信号来确定期望频率与振荡信号的频率之间的比率。 振荡信号可以通过该比率被抽取，以产生具有大致期望频率的合成信号。 在一个方面，可以通过响应于以比例的步长积累的累加器的输出产生脉冲来执行抽取。 为了节省电力，振荡信号可以从低功率振荡器导出，而参考信号可以仅在周期性校准期间被导通。 公开了用于提高合成信号的频率精度的其它方面。
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