SUBSET SELECTION OF RFID TAGS USING LIGHT
    2.
    发明申请
    SUBSET SELECTION OF RFID TAGS USING LIGHT 有权
    选择使用光的RFID标签

    公开(公告)号:US20120249303A1

    公开(公告)日:2012-10-04

    申请号:US12420009

    申请日:2009-04-07

    IPC分类号: G06K7/01 H03K17/22 G06K19/073

    摘要: Methods and apparatuses for selecting a subset of RFID tags are provided in some embodiments. These methods and apparatuses utilize the susceptibility to light by persistent nodes found in passive tags. Light can be used to intentionally reduce persistence times in a particular subset tags or even an individual tag. Then, persistent nodes can be used as a selection criterion to distinguish previously illuminated tags from non-illuminated tags. In other embodiments, a power circuit receives a RF input source and generates a direct current (DC) output voltage. The circuit includes a bias circuit to supply a gate to source bias, which is independent of the DC output voltage. The circuit further includes a voltage multiplier circuit that is coupled to the bias circuit. The voltage multiplier circuit has MOS transistors with one transistor to receive the gate to source bias.

    摘要翻译: 在一些实施例中提供了用于选择RFID标签子集的方法和装置。 这些方法和装置利用被动标签中发现的持久节点对光的敏感性。 光可用于有意减少特定子集标签甚至单个标签中的持续时间。 然后,持久性节点可以用作选择标准,以区分先前照亮的标签和非照明标签。 在其他实施例中,电源电路接收RF输入源并产生直流(DC)输出电压。 该电路包括一个偏置电路,用于提供栅极与源极偏置,其独立于直流输出电压。 电路还包括耦合到偏置电路的电压倍增器电路。 电压倍增器电路具有MOS晶体管,其中一个晶体管接收栅极到源偏置。

    Noise cancellation for RFID backscatter
    8.
    发明授权
    Noise cancellation for RFID backscatter 有权
    RFID反向散射的噪声消除

    公开(公告)号:US08340581B2

    公开(公告)日:2012-12-25

    申请号:US12617534

    申请日:2009-11-12

    IPC分类号: H04B15/00

    CPC分类号: G06K7/0008

    摘要: Methods and apparatuses for removing unwanted noise by a radio frequency identification (RFID) interrogator are provided. The interrogator transmits a transmitted signal while receiving a received signal. The received signal can include backscatter modulated signals from one or more RFID tags, as well as unmodulated reflections of the transmitted signal from the environment. The unmodulated reflections are undesirable and may make tag signal extraction difficult. A canceling signal is summed with the received signal to cancel or reduce the unmodulated reflections prior to tag signal extraction. In a specific embodiment, a phase shifted, amplitude adjusted reflection of the transmit signal is used by a directional coupler as the canceling signal.

    摘要翻译: 提供了通过射频识别(RFID)询问器去除不想要的噪声的方法和装置。 询问器在接收到接收到的信号的同时发送发送的信号。 所接收的信号可以包括来自一个或多个RFID标签的后向散射调制信号,以及来自环境的发射信号的未调制反射。 未调制的反射是不期望的,并且可能使标签信号提取困难。 消除信号与接收信号相加以消除或减少标签信号提取之前的未调制反射。 在具体实施例中,定向耦合器使用发射信号的相移幅度调整反射作为消除信号。