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9 条记录 (耗时 0.021 秒)

    Combined low frequency receive and high frequency transceive antenna system and method
    6.
    发明授权
    Combined low frequency receive and high frequency transceive antenna system and method 失效
    组合低频接收和高频收发天线系统及方法

    公开(公告)号：US5170493A

    公开(公告)日：1992-12-08

    申请号：US223911

    申请日：1988-07-25

    申请人： Stephen A. Roth

    发明人： Stephen A. Roth

    IPC分类号： H01Q5/00 ,  H01Q5/50 ,  H04B1/18 ,  H04B1/48

    CPC分类号： H04B1/48 ,  H01Q5/50 ,  H04B1/18

    摘要： A dual function antenna system and method. A system is provided for using a single antenna for both the reception of low frequency navigational signals, such as LORAN-C, and high frequency communications signals in the VHF region. The antenna is at a remote location from a low frequency receiver and a high frequency transceiver. Both the low frequency and the high frequency signals are coupled to the receiver and transceiver, respectively, over the same transmission line at one end thereof. A preamplifier is provided at the location of the antenna to increase the strength of the low frequency signal applied to the transmission line. A high pass filter is provided to couple the antenna and the transmission line and prevent feedback from the output of the preamplifier from reaching its input. The other end of the transmission line is coupled to the high frequency transceiver by a high pass filter, and to the low frequency receiver by a low pass filter. The preamplifier is supplied with DC power over the transmission line, and includes a current regulator so that the preamplifier may be used with a wide range of supply voltages.

    摘要翻译： 双功能天线系统和方法。 提供了一种用于使用单个天线用于接收诸如LORAN-C的低频导航信号和VHF区域中的高频通信信号的系统。 天线位于远离低频接收机和高频收发器的位置。 低频信号和高频信号都分别通过同一传输线在其一端耦合到接收机和收发机。 在天线的位置处提供前置放大器以增加施加到传输线的低频信号的强度。 提供高通滤波器以耦合天线和传输线，并防止来自前置放大器的输出的反馈到达其输入。 传输线的另一端通过高通滤波器耦合到高频收发器，并通过低通滤波器耦合到低频接收器。 前置放大器通过传输线提供直流电，并且包括电流调节器，使得前置放大器可以在宽范围的电源电压下使用。

    Bit detection threshold in a TDMA burst communication system
    7.
    发明授权
    Bit detection threshold in a TDMA burst communication system 有权

    公开(公告)号：US07068725B2

    公开(公告)日：2006-06-27

    申请号：US09892166

    申请日：2001-06-26

    申请人： Stephen A. Roth ,  Thomas L. Mosher

    发明人： Stephen A. Roth ,  Thomas L. Mosher

    IPC分类号： H04L25/34 ,  H04L27/10 ,  H03D3/00

    CPC分类号： H04L25/062

    摘要： A method is disclosed for optimally adjusting the received bit detection threshold in a digital communication system, such as a TDMA system that is characterized by very short duration burst transmissions. In one embodiment of the invention, a half-duplex radio modem is used for transmission and receipt of messages for airborne and ground-based Automatic Dependent Surveillance-Broadcast (ADS-B) service. A feedback path is provided for in the transmission/receiver unit to provide the transmission signal to the receiver path. A bit detection threshold adjustment circuit receives the transmission signal. The circuit digitizes the analog baseband signal, detects the positive and negative peak values and calculates a peak-to-peak deviation value to define the bit detection threshold value.

    Low power, high accuracy magnetometer and magnetic field strength measurement method
    8.
    发明授权
    Low power, high accuracy magnetometer and magnetic field strength measurement method 失效
    低功率，高精度磁力计和磁场强度测量方法

    公开(公告)号：US5091697A

    公开(公告)日：1992-02-25

    申请号：US388579

    申请日：1989-07-31

    申请人： Stephen A. Roth ,  Roar Berg-Johansen

    发明人： Stephen A. Roth ,  Roar Berg-Johansen

    IPC分类号： G01R33/04

    CPC分类号： G01R33/045

    摘要： A magnetometer and method for measuring magnetic field strength particularly adapted for use in an electronic flux gate compass. A core of magnetic material in the shape of a toroid is coupled to a drive coil and to two sense coils oriented along orthogonal axes. A current limited, current source coupled to the drive coil periodically saturates the core, drives the core out of saturation at an intermediate current level, and saturates the core again. Each sense coil is coupled to a sense circuit which measures the current in the sense coil induced by the periodically changing flux density in the coil resulting from an external magnetic field coupled to the sense coil, produces a dc feedback signal to cancel out the external magnetic field, and provides the dc signal as an output representative of the external magnetic field strength along the axis of the sense coil. The dc signal is produced by synchronously detecting the amplified ac current in the sense coil. Low pass filters are provided to eliminate ac components from the magnetometer output.

    摘要翻译： 用于测量磁场强度的磁力计和方法，特别适用于电子通量门罗盘。 具有环形形状的磁性材料的核心耦合到驱动线圈和沿正交轴线定向的两个感测线圈。 耦合到驱动线圈的电流有限的电流源周期性地使核心饱和，从而使核心以中间电流水平驱动饱和，并使核心再次饱和。 每个感测线圈耦合到感测电路，该感测电路测量由耦合到感测线圈的外部磁场引起的由线圈中周期性变化的磁通密度引起的感测线圈中的电流，产生直流反馈信号以抵消外部磁 并且提供直流信号作为代表感测线圈的轴的外部磁场强度的输出。 通过同步检测感测线圈中的放大的交流电流来产生直流信号。 提供低通滤波器以消除磁力计输出中的交流分量。

    Dynamically variable attenuator
    9.
    发明授权
    Dynamically variable attenuator 失效
    动态可变衰减器

    公开(公告)号：US4845446A

    公开(公告)日：1989-07-04

    申请号：US945216

    申请日：1986-12-19

    申请人： Stephen A. Roth

    发明人： Stephen A. Roth

    IPC分类号： H03H11/24

    CPC分类号： H03H11/24

    摘要： A variable attenuator comprises a plurality of attenuator stages connected in series along a transmission line signal path. Each attenuator stage comprises a resstive pi-section attenuating pad which may be selectively inserted into the signal path to increase attenuation along the path. Each series element of the pad is selectively inserted or removed from the signal path by opening or closing a parallel connected switching device, while each shunt element of the pad is selectively connected to or disconnected from ground by closing or opening a corresponding series connected switching device. The switching devices each comprise an NPN bipolar transistor and a PNP bipolar transistor, the emitter of each transistor being coupled to the emitter of the other and the collector or each transistor being connected to the collector of the other, to provide a low impedance AC signal path from collector to emitter when the transistors are active.

    摘要翻译： 可变衰减器包括沿着传输线信号路径串联连接的多个衰减器级。 每个衰减器级包括一个残留的pi部分衰减焊盘，该焊盘可被选择性地插入到信号路径中以增加沿着该路径的衰减。 通过打开或关闭并联的开关装置，可以选择性地将插脚的每个串联元件从信号路径插入或移除，同时通过闭合或打开相应的串联连接的开关装置来选择性地将焊盘的每个分流元件连接到或断开 。 开关器件各自包括NPN双极晶体管和PNP双极晶体管，每个晶体管的发射极耦合到另一个的发射极，并且集电极或每个晶体管连接到另一个的集电极，以提供低阻抗AC信号 当晶体管处于活动状态时，从集电极到发射极的路径。