公开(公告)号：US06625424B1

公开(公告)日：2003-09-23

申请号：US09531944

申请日：2000-03-21

申请人： Rishi Mohindra

发明人： Rishi Mohindra

IPC分类号： H04B138

CPC分类号： H03C3/40 ,  H03D7/166 ,  H04B1/30

摘要： A quadrature tranceiver has a transmitter, a receiver, and a common local oscillator. With the transmitter switched off and the receiver switched on, a DC-error in the receiver is nulled in servo loops in in-phase and a quadrature receiver paths. After settling, the servo loops provide output values that are freed of the DC-error. DC-nulling output values are then sampled and stored. After sampling, the servo loops are opened. Thereafter, the transmitter is switched on while inputting a fixed signal to the transmitter, and DC-signals injected into in-phase and quadrature paths of the transmitter are adjusted until the opened servo loops provide the same output signal as obtained at the end of the DC-nulling. Corresponding values of the injected DC-signals are then stored as transmitter calibration values.

摘要翻译： 正交发射器具有发射器，接收器和公共本地振荡器。 在发射机关闭并且接收机接通的情况下，接收机中的直流误差在同相和正交接收器路径的伺服环路中为零。 稳定后，伺服环路提供无直流误差的输出值。 然后对直流归零输出值进行采样和存储。 采样后，打开伺服回路。 此后，在向发射机输入固定信号的同时接通发射机，并且调整注入到发射机的同相和正交路径中的DC信号，直到打开的伺服环路提供与在发射机末端获得的相同的输出信号 直流归零。 然后将注入的DC信号的相应值存储为发射机校准值。

公开(公告)号：US6137353A

公开(公告)日：2000-10-24

申请号：US107184

申请日：1998-06-29

申请人： Peter Stroet ,  Rishi Mohindra

发明人： Peter Stroet ,  Rishi Mohindra

IPC分类号： H03H7/18 ,  H03D3/02 ,  H03D3/06 ,  H03H7/19 ,  H03H11/18

CPC分类号： H03D3/02

摘要： An approach for demodulating a frequency-modulated signal involves processing a frequency-modulated signal with a phase shifter network to provide a demodulated signal that has a relatively constant amplitude around the center frequency of the frequency-modulated signal and that exhibits a relatively linear phase change over an operational frequency range. Embodiments of the invention include a phase shifter network, using N number of cascaded all-pass filters, that receives as an input a limited amplitude signal and outputs a phase-shifted limited amplitude signal that is mixed with the limited amplitude signal. The phase shifter network may also comprise a low-pass bessel filter.

摘要翻译： 用于解调频率调制信号的方法涉及用移相器网络处理频率调制信号，以提供在调频信号的中心频率周围具有相对恒定振幅的解调信号，并且显示相对线性的相位变化 超过工作频率范围。 本发明的实施例包括使用N个级联全通滤波器的移相器网络，其接收有限振幅信号作为输入，并输出与限幅振幅信号混合的相移限幅振幅信号。 移相器网络还可以包括低通贝塞尔滤波器。

公开(公告)号：US09116582B2

公开(公告)日：2015-08-25

申请号：US13370087

申请日：2012-02-09

申请人： Rishi Mohindra ,  Guozhong Shen ,  Kenneth W. Knox

发明人： Rishi Mohindra ,  Guozhong Shen ,  Kenneth W. Knox

IPC分类号： G06F3/045 ,  G06F3/044

CPC分类号： G06F3/044 ,  G06F2203/04111

摘要： A capacitive touch panel includes elongated drive electrodes arranged next to one another and having a characteristic spacing between adjacent drive electrodes. The capacitive touch panel also includes elongated sensor electrodes arranged next to one another across the drive electrodes and having a characteristic spacing between adjacent sensor electrodes. The drive electrodes and/or the sensor electrodes have protrusions into the spaces between adjacent electrodes. The characteristic spacing between the sensor electrodes may be at least substantially greater than the characteristic spacing between the drive electrodes. The sensor electrodes may have a pitch based upon a touch diameter of a finger, and the touch panel may be capable of sensing a stylus having a touch diameter substantially less than the touch diameter of the finger.

摘要翻译： 电容式触摸面板包括彼此相邻布置的细长的驱动电极，并且在相邻的驱动电极之间具有特征间隔。 电容式触摸面板还包括在驱动电极之间彼此相邻布置的细长传感器电极，并且在相邻的传感器电极之间具有特征间隔。 驱动电极和/或传感器电极具有突出到相邻电极之间的空间中。 传感器电极之间的特征间距可至少基本上大于驱动电极之间的特征间隔。 传感器电极可以具有基于手指的触摸直径的间距，并且触摸面板可以能够感测具有基本上小于手指的触摸直径的触摸直径的触笔。

公开(公告)号：US20140327644A1

公开(公告)日：2014-11-06

申请号：US13887373

申请日：2013-05-06

申请人： Rishi Mohindra

发明人： Rishi Mohindra

IPC分类号： G06F3/044

CPC分类号： G06F3/044 ,  G06F3/0416

摘要： A touch-sensitive device includes a touch panel, drive unit, and measurement unit. A touch applied to a given node of the panel changes a mutual capacitive coupling between a given drive and sense electrode of the touch panel, or changes a self-capacitive coupling the between a given electrode and ground. The drive unit delivers to the drive electrodes of the touch panel or to the self-capacitance measurement amplifiers of all electrodes, subcarriers of a composites carrier modulated OFDM signal by using SSB or DSB modulation based up-conversion, and these subcarriers are complementary code sequence-based phase encoded for PAPR reduction of the OFDM signal. The measurement unit receives signals from the receive electrodes, or directly from local receiver amplifiers at each electrode, and analyzes the signal using FFT or maximum likelihood estimation to determine the mutual coupling capacitance between each of the drive and receive electrodes or the self-capacitance of each electrode. Time-windowing is applied inside the FFT window, and a tone skipping or nulling technique is adopted, when it is required to reject interferences at frequencies that are too close to that of the drive signal frequencies.

摘要翻译： 触敏装置包括触摸面板，驱动单元和测量单元。 施加到面板的给定节点的触摸改变了触摸面板的给定驱动和感测电极之间的互电容耦合，或者改变给定电极和地之间的自电容耦合。 驱动单元通过使用基于SSB或基于DSB调制的上变频来传送到触摸面板的驱动电极或所有电极的自电容测量放大器，复合载波调制OFDM信号的子载波，并且这些子载波是互补码序列 的相位编码用于OFDM信号的PAPR降低。 测量单元接收来自接收电极的信号，或直接从每个电极处的本地接收器放大器接收信号，并且使用FFT或最大似然估计来分析信号，以确定每个驱动和接收电极之间的互耦合电容或 每个电极。 在FFT窗口内部应用时间窗口，当需要在与驱动信号频率太接近的频率上拒绝干扰时，采用跳频或归零技术。

公开(公告)号：US20130207923A1

公开(公告)日：2013-08-15

申请号：US13370087

申请日：2012-02-09

申请人： Rishi Mohindra ,  Guozhong Shen ,  Kenneth W. Knox

发明人： Rishi Mohindra ,  Guozhong Shen ,  Kenneth W. Knox

IPC分类号： G06F3/044

CPC分类号： G06F3/044 ,  G06F2203/04111

摘要： A capacitive touch panel includes elongated drive electrodes arranged next to one another and having a characteristic spacing between adjacent drive electrodes. The capacitive touch panel also includes elongated sensor electrodes arranged next to one another across the drive electrodes and having a characteristic spacing between adjacent sensor electrodes. The drive electrodes and/or the sensor electrodes have protrusions into the spaces between adjacent electrodes. The characteristic spacing between the sensor electrodes may be at least substantially greater than the characteristic spacing between the drive electrodes. The sensor electrodes may have a pitch based upon a touch diameter of a finger, and the touch panel may be capable of sensing a stylus having a touch diameter substantially less than the touch diameter of the finger.

摘要翻译： 电容式触摸面板包括彼此相邻布置的细长的驱动电极，并且在相邻的驱动电极之间具有特征间隔。 电容式触摸面板还包括在驱动电极之间彼此相邻布置的细长传感器电极，并且在相邻的传感器电极之间具有特征间隔。 驱动电极和/或传感器电极具有突出到相邻电极之间的空间中。 传感器电极之间的特征间距可至少基本上大于驱动电极之间的特征间隔。 传感器电极可以具有基于手指的触摸直径的间距，并且触摸面板可以能够感测具有基本上小于手指的触摸直径的触摸直径的触笔。

公开(公告)号：US20120313890A1

公开(公告)日：2012-12-13

申请号：US13479428

申请日：2012-05-24

申请人： Rishi Mohindra

发明人： Rishi Mohindra

IPC分类号： G06F3/044

CPC分类号： G06F3/0416 ,  G06F3/0418 ,  G06F3/044 ,  G06F3/047

摘要： A touch panel system is described that is configured to reduce inter-symbol interference (ISI). In an implementation, the touch panel system includes a touch panel assembly that includes a plurality of drive electrodes arranged one next to another and a plurality of sensor electrodes arranged one next to another across the drive electrodes to form a plurality of pixels having a mutual capacitance. The touch panel system also includes a transmitter configured to drive the drive electrodes with drive signals derived at least partially from excitation values. The transmitter is configured to apply a window function to the drive signals. The system also includes a receiver configured to sense signals furnished from the sensor electrodes and to determine the mutual capacitance of the pixels.

摘要翻译： 描述了被配置为减少符号间干扰（ISI）的触摸面板系统。 在一个实施方案中，触摸面板系统包括触摸面板组件，其包括彼此相邻布置的多个驱动电极和在驱动电极之间彼此相邻布置的多个传感器电极，以形成具有互电容的多个像素 。 触摸面板系统还包括被配置为通过至少部分地从激励值导出的驱动信号来驱动驱动电极的发射器。 变送器配置为对驱动信号应用窗口功能。 该系统还包括被配置为感测从传感器电极提供的信号并确定像素的互电容的接收器。

公开(公告)号：US07899424B2

公开(公告)日：2011-03-01

申请号：US11536312

申请日：2006-09-28

申请人： Rishi Mohindra

发明人： Rishi Mohindra

IPC分类号： H04B1/06

CPC分类号： H03G3/3047

摘要： A method for reducing frequency glitches in a digital transceiver due to power amplifier input impedance variations. According to the method, the power amplifier is switched on after the end of a prior packet reception period and before a new packet transmission begins. Instead of ramping the power amplifier gain, the method ramps the modulation signals. As a consequence, any VCO frequency transients that may result from turning on the power amplifier have an opportunity to decay before the new packet transmission is initiated. This technique effectively isolates the transmitter power amplifier from the frequency synthesizer VCO to facilitate fast switching transceiver operation.

摘要翻译： 由于功率放大器输入阻抗变化，减少数字收发器中的频率毛刺的方法。 根据该方法，功率放大器在先前分组接收周期结束之后并且在新分组传输开始之前被接通。 而不是使功率放大器增益变化，该方法会使调制信号变化。 因此，由于开启功率放大器可能产生的任何VCO频率瞬变都有可能在新分组传输启动之前衰减。 这种技术有效地将发射机功率放大器与频率合成器VCO隔离，以便于快速切换收发器操作。

公开(公告)号：US07532873B2

公开(公告)日：2009-05-12

申请号：US11454089

申请日：2006-06-14

申请人： Rishi Mohindra

发明人： Rishi Mohindra

IPC分类号： H04B1/06 ,  H04B7/00

CPC分类号： H04B1/30

摘要： This invention describes how to quickly cancel DC offsets that are present in the two quadrature paths of a zero intermediate frequency transceiver. Previously known techniques are not suitable for the 5 GHz WLAN standards because of the very short transmit to receive turn around times and extraordinarily large DC offsets in these systems. This invention solves the above problems. The present invention uses both AC and DC coupling along with automatic gain control techniques to remove unwanted DC offsets within an acceptable time period. The invention further uses a digital signal processor to estimate and subtract out the DC offset errors using time averaged signals. The digital signal processing circuit is capable of further AC filtering and Analog to Digital conversions.

摘要翻译： 本发明描述了如何快速消除存在于零中频收发器的两个正交路径中的DC偏移。 以前已知的技术不适用于5 GHz WLAN标准，因为这些系统中传输非常短的接收时间和非常大的直流偏移量。 本发明解决了上述问题。 本发明使用AC和DC耦合以及自动增益控制技术来在可接受的时间段内去除不需要的DC偏移。 本发明还使用数字信号处理器来使用时间平均信号来估计和减去DC偏移误差。 数字信号处理电路能够进一步进行交流滤波和模数转换。

公开(公告)号：US06721548B1

公开(公告)日：2004-04-13

申请号：US09469330

申请日：1999-12-22

申请人： Rishi Mohindra ,  Petrus M. Stroet

发明人： Rishi Mohindra ,  Petrus M. Stroet

IPC分类号： H04B1700

CPC分类号： H04B17/318

摘要： A received signal strength indicator operating at low intermediate of zero intermediate frequency is provided. The received signal strength indicator forms absolute values from an in-phase signal component and a quadrature signal component of a low or zero intermediate frequency signal that represents a received radio frequency signal. The absolute values are added. Logarithmic signal processing is performed either before absolute signal forming or after adding. Finally, low pass filtering is performed.

摘要翻译： 提供了在零中频的低中间运行的接收信号强度指示器。 接收到的信号强度指示器表示来自表示所接收的射频信号的低或零中频信号的同相信号分量和正交信号分量的绝对值。 添加绝对值。 在绝对信号形成之前或之后进行对数信号处理。 最后，执行低通滤波。

公开(公告)号：US06621879B1

公开(公告)日：2003-09-16

申请号：US08668114

申请日：1996-06-21

申请人： Rishi Mohindra

发明人： Rishi Mohindra

IPC分类号： H04L2714

CPC分类号： H03D3/06 ,  H03D3/22

摘要： A digital radio device having a quadrature demodulator that does not suffer from substantial amplitude roll-off at the relevant operating range. Such a device is obtained by a phase shifting network in a quadrature branch of the demodulator having a series arrangement of a resistor and an capacitor coupled to an inductor coupled to ground. A junction between the series arrangement and the inductor forms the output of the quadrature branch. Alternative embodiments are provided. The demodulator avoids asymmetric digital signal distortion which can have deteriorating effects, in particular to GFSK-signals or &pgr;/4-DQPSK signals, or the like, and further noise shift of data which is of particular importance in low [S/N]-systems such as paging systems.

摘要翻译： 具有正交解调器的数字无线电设备，其在相关工作范围内不会遭受相当大幅度的滚降。 这样的器件通过解调器的正交分支中的相移网络获得，该解调器具有电阻器和耦合到耦合到地的电感器的电容器的串联布置。 串联装置和电感之间的结点形成正交分支的输出。 提供了替代实施例。 解调器避免了可能具有劣化影响的非对称数字信号失真，特别是GFSK信号或pi / 4-DQPSK信号等，以及在低[S / N] - 诸如寻呼系统的系统。