Constant-phase, gain-controlled amplification circuit
    2.
    发明授权
    Constant-phase, gain-controlled amplification circuit 失效
    恒相,增益控制放大电路

    公开(公告)号:US07085333B2

    公开(公告)日:2006-08-01

    申请号:US10124215

    申请日:2002-04-15

    IPC分类号: H04L27/08

    摘要: An amplification circuit (10) is used in a radio receiver (12) to achieve both constant phase shift over the gain range and low intermodulation. A gain-controlled amplifier (16) is desirably optimized for good fidelity, even if at the expense of poor phase linearity. A phase shift compensator (48) compensates for phase non-linearity by imposing a delay of variable duration downstream of the gain-controlled amplifier (16). The delay duration is determined in response to a gain-control signal (20) generated by an AGC circuit (42). The gain-control signal (20) is translated through a look-up table (62) into delay values which control a programmable delay element (64). The programmable delay element (64) generates an adjusted clock signal (54) that drives a digitizer (36). The digitizer (36) both digitizes and delays an amplified signal (32) produced by gain-controlled amplifier (16).

    摘要翻译: 在无线电接收机(12)中使用放大电路(10),以实现增益范围上的恒定相移和低互调。 期望优化增益控制放大器(16)以获得良好的保真度,即使以较差的相位线性度为代价。 相移补偿器(48)通过在增益控制放大器(16)的下游施加可变持续时间的延迟来补偿相位非线性。 响应于由AGC电路(42)产生的增益控制信号(20)确定延迟持续时间。 增益控制信号(20)通过查找表(62)转换成控制可编程延迟元件(64)的延迟值。 可编程延迟元件(64)产生驱动数字转换器(36)的经调整的时钟信号(54)。 数字转换器(36)都对由增益控制放大器(16)产生的放大信号(32)进行数字化和延迟。

    Method and apparatus for providing additional resources in a satellite
communication system
    3.
    发明授权
    Method and apparatus for providing additional resources in a satellite communication system 失效
    在卫星通信系统中提供附加资源的方法和装置

    公开(公告)号:US5978653A

    公开(公告)日:1999-11-02

    申请号:US850543

    申请日:1997-05-02

    IPC分类号: H04B7/185 H04B7/195

    CPC分类号: H04B7/195 H04B7/18521

    摘要: Additional resources and services are provided in a satellite communication system (100) through the use of seam satellites (52). One or more seam satellites (52) are coupled to communication satellites (12) in an existing constellation using previously unused crosslinks. The seam satellites (52) are located between orbital planes (31 and 36) in which the communication satellites (12) are moving in opposite directions with respect to each other. Seam satellites (52) can provide new services such as earth sensing and observation. Seam satellites (52) can also provide attachment points for other new space-based users. Some of the communication units (26) can communicate with the seam satellites (52) via communication satellites (12). This allows these communication units (26) to use the new services provided by the seam satellite (52). Seam satellites (52) can be controlled by separate control centers or can be controlled by the control center for the communication satellites (12).

    摘要翻译: 通过使用接缝卫星(52)在卫星通信系统(100)中提供额外的资源和服务。 一个或多个接缝卫星(52)使用先前未使用的交联联接到现有星座中的通信卫星(12)。 接缝卫星(52)位于通信卫星(12)相对于彼此相反方向移动的轨道平面(31和36)之间。 Seam卫星(52)可以提供诸如地球感测和观测的新服务。 Seam卫星(52)还可以为其他新的基于空间的用户提供附件点。 一些通信单元(26)可以经由通信卫星(12)与接缝卫星(52)通信。 这允许这些通信单元(26)使用由接缝卫星(52)提供的新服务。 接缝卫星(52)可以由单独的控制中心控制,或者由通信卫星的控制中心(12)控制。