公开(公告)号：US5128669A

公开(公告)日：1992-07-07

申请号：US575113

申请日：1990-08-30

Applicant: Alan F. Dadds ,  Kenneth Holford ,  David M. Nugent ,  Brian J. Stocker

Inventor： Alan F. Dadds ,  Kenneth Holford ,  David M. Nugent ,  Brian J. Stocker

IPC: H04B7/26 ,  G01S13/76 ,  G07B15/06 ,  G08G1/017 ,  G08G1/0967

CPC classification number: G08G1/096716 ,  G01S13/765 ,  G07B15/063 ,  G08G1/017 ,  G08G1/096758 ,  G08G1/096783

Abstract: Information is communicated by microwave radio between transponders (9,10) carried by vehicles (7,8) travelling on a road (1) and a station (22) adjacent the road. The communications from the transponders are effected by the transponders suitably modulating their reflections of beams of microwave energy transmitted by the station from aerials (B) mounted on a gantry (11) above the road, these aerials irradiating respective communication areas (28,29,30). In order to prevent communications from different transponders overlapping and hence interfering with each other the transponders are enabled for their communications by microwave energy from further aerials (A), which energy has a higher frequency to enable it to be beamed at relatively small respective activation areas (23-27) the sizes of which are such that they can each only contain one vehicle and hence one transponder at any given time. The further aerials are activated, one at a time, successively and cyclically, so that the transponders are necessarily enabled in succession, the activation rate being, moreover, sufficient to ensure that all transponders passing through the relevant stretch of road are in fact enabled. During each interval between the activation of each further aerial and the next the station transmits a command from the aerial(s) (B) associated with the further aerial (A) which has just been activated ordering any transponder which has just been enabled to communicate its presence. If it receives such a communication the station transmits an address code from the relevant aerial(s) (B) which is stored in the relevant transponder and used subsequently to selectively address that transponder for further communication.

公开(公告)号：US4914380A

公开(公告)日：1990-04-03

申请号：US281575

申请日：1988-12-08

Applicant: Alan F. Dadds

Inventor： Alan F. Dadds

IPC: G01R23/14 ,  H03D7/00 ,  H03D7/16

CPC classification number: G01R23/14 ,  H03D7/00 ,  H03D7/165

Abstract: A signal receiving arrangement comprising first and second groups (14, 16) of frequency down-converting stages (18 to 24 and 26 to 34), each stage including a mixer (40) and a local oscillator (42) for frequency down-converting a signal applied to the stages (18 to 24 and 26 to 34), the local oscillator frequencies of successive stages (18 to 24 and 26 to 34) being progressively higher with the frequency differences between successive stages in each group forming an arithmetic progression, wherein the frequency down-converted outputs of the stages of each group are combined and the pair of residue frequencies formed by mixing down the input signal are used to determine on the basis of the Chinese remainder theorem which stage in each group was operative on the input signal and thereby ascertain the actual frequency of the input signal.

公开(公告)号：US4857937A

公开(公告)日：1989-08-15

申请号：US132508

申请日：1987-12-14

Applicant: Alan F. Dadds

Inventor： Alan F. Dadds

IPC: H01Q25/00

CPC classification number: H01Q25/008

Abstract: In, for example, a passive direction-finding radio receiver employing a multi-beam antenna which has e.g. ninety-six feeds which form a corresponding number of overlapping reception beams, the output signal amplitudes of the various feeds can be compared with a reference to yield a sequence of binary digits, e.g. as shown in FIG. 2. The position of a radio source is given by the position in the sequence of the center of the largest group of "1"s. In order to quickly determine this position the sequence is subjected repeatedly to a processing operation in which each "1" which does not have "1"s as its two immediate neighbors is changed to a "0", thereby repeatedly stripping the two end "1"s off each group of "1"s until none remain. The required position is that of the single "1" or pair of "1"s present immediately before all have become "0"s.

Abstract translation: 例如，在采用多波束天线的无源定向无线电接收机中， 形成相应数量的重叠接收波束的九十六个馈送，可以将各种馈送的输出信号幅度与参考进行比较以产生二进制数字的序列，例如。 如图1所示。 2.无线电源的位置由最大组“1”的中心顺序给出。 为了快速确定该位置，将序列重复地进行到其中不具有“1”作为其两个立即邻居的每个“1”改变为“0”的处理操作，从而反复地剥离两端“ 1组，每组“1”，直到不存在。 所需的位置是紧接在“0”之前的单个“1”或“1”对的位置。

公开(公告)号：US4797679A

公开(公告)日：1989-01-10

申请号：US59730

申请日：1987-06-09

Applicant: Anthony R. Cusdin ,  Alan F. Dadds ,  Peter Mallinson

Inventor： Anthony R. Cusdin ,  Alan F. Dadds ,  Peter Mallinson

IPC: G01S3/50 ,  G04F10/00 ,  G01S1/24

CPC classification number: G04F10/00 ,  G01S3/50

Abstract: A method and a system for radio direction-finding by measuring the Time of Arrival (ToA) of the leading edge of signals from a distant source at two relatively closely spaced receiving elements. In order to give a good degree of immunity to multipath, the times at which the instantaneous detected amplitudes of the received signals first exceed a minimal threshold value such that received signals can be satisfactorily distinguished from noise is measured in such a manner that the measured time is not affected by multipath which involves more than a few meters additional path length for the indirect, delayed signal. A suitable timing circuit is disclosed.By making ToA measurements on three coplanar, non-collinear receivers, directions of incidence in three dimensions can be determined.A method and a system using both ToA and phase-difference measurements can provide the accuracy of interferometry but be simpler and cheaper.

Abstract translation: 一种用于无线电测向的方法和系统，通过测量两个相对接近间隔的接收元件的来自远距离源的信号的前沿的到达时间（ToA）。 为了给予多路径的良好程度的抗扰度，接收信号的瞬时检测到的幅度首先超过最小阈值的时间使得接收到的信号可以令人满意地与噪声区分开来测量时间， 不受多路径影响，间接延迟信号涉及多于几米的额外路径长度。 公开了一种合适的定时电路。 通过对三个共面非共线接收器进行ToA测量，可以确定三维的入射方向。 使用ToA和相位差测量的方法和系统可以提供干涉测量的精度，但是更简单和更便宜。