Antenna system
    1.
    发明授权
    Antenna system 失效
    天线系统

    公开(公告)号:US06836254B2

    公开(公告)日:2004-12-28

    申请号:US10215704

    申请日:2002-08-10

    IPC分类号: H01Q1310

    摘要: Provided is an antenna system for operating in clear line of sight and obscured line of sight conditions. The antenna system includes multiple antenna elements arranged to provide both space and angle diversity characteristics. The elements are spaced apart so as to provide independence but may have overlapping radiation patterns. Each element includes a main radiation lobe and the elements are arranged so that the main radiation lobes are oriented at diverse angles.

    摘要翻译: 提供了一种用于在清晰的视线和视线条件下视线操作的天线系统。 天线系统包括布置成提供空间和角度分集特性的多个天线元件。 元件间隔开以提供独立性,但是可以具有重叠的辐射图案。 每个元件包括主辐射波瓣,并且元件布置成使得主辐射波瓣以不同的角度定向。

    Electronic phase comparison apparatus for the remote measurement of
layer thickness
    2.
    发明授权
    Electronic phase comparison apparatus for the remote measurement of layer thickness 失效
    用于远程测量层厚度的电子相位比较装置

    公开(公告)号:US4075555A

    公开(公告)日:1978-02-21

    申请号:US781506

    申请日:1977-03-25

    IPC分类号: G01B7/06 G01R25/02 G01R27/04

    CPC分类号: G01R25/02 G01B7/06

    摘要: A continuous wave, phase measurement system which provides at least an order of magnitude improvement in accuracy over modulated carrier systems is disclosed for the determination of the thicknesses of layered targets consisting of a known number of dielectric layers, each of a known maximum thickness. This system uses related frequencies such as the fundamental and its harmonics to establish a multi-harmonic coherence relationship whereby a homodyne phase reference between harmonics can be conserved and information extracted from just the received and not the transmitted signals. Consequently doppler effects due to motion between the target and the apparatus, as well as severe local oscillator stability and drift limitations are avoided, and thus this system can measure remote target parameters by interferometric techniques without the distance being a constraint.