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公开(公告)号：US5428830A
公开(公告)日：1995-06-27
申请号：US123124
申请日：1993-09-17
CPC分类号： H01Q23/00 , H01Q1/1278 , H04B1/18
摘要： A concealed antenna system for motor vehicle radios replaces a radio chassis preamplifier with a remote radio frequency amplifier packaged with a filter module adjacent the antenna conductors to reduce the noise floor before transmitting the signal by a highly capacitive cable to the radio chassis. The dynamic range of the antenna system is improved by an automatic gain control feedback signal from the radio chassis to the RF amplifier so that the gain of the amplifier is reduced in the presence of a strong AM signal. Preferably the antenna conductors comprise embedded conductors in an insulating panel of a motor vehicle such as the vehicle rear window, and the AM conductor may be conveniently provided by the heater grid for the window panel.
摘要翻译： 用于机动车辆无线电的隐蔽天线系统用与天线导体相邻的滤波器模块封装的远程射频放大器替换无线电机架前置放大器，以在通过高电容电缆将信号传输到无线电底盘之前降低噪声底限。 通过从无线电机架到RF放大器的自动增益控制反馈信号来改善天线系统的动态范围，使得在存在强AM信号的情况下放大器的增益被减小。 优选地，天线导体包括诸如车辆后窗的机动车辆的绝缘面板中的嵌入式导体，并且AM导体可以由用于窗口面板的加热器栅格方便地提供。
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公开(公告)号：US4590613A
公开(公告)日：1986-05-20
申请号：US564911
申请日：1983-12-23
CPC分类号： H03G3/3063
摘要： A common emitter transistor amplifier has a control transistor coupled between its collector and base. The base of the control transistor receives an AGC voltage so that the control transistor varies the base current and hence the gain of the common emitter transistor. The common emitter transistor is used as an RF amplifier in a double conversion television tuner having a doubly balanced first mixer. Varying the gain of the RF stage protects the mixer from overload.
摘要翻译： 共同的发射极晶体管放大器具有耦合在其集电极和基极之间的控制晶体管。 控制晶体管的基极接收AGC电压，使得控制晶体管改变基极电流，从而改变公共发射极晶体管的增益。 普通发射极晶体管用作具有双平衡第一混频器的双转换电视调谐器中的RF放大器。 改变RF级的增益保护混频器免受过载。
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3.发明授权
公开(公告)号：US5483247A
公开(公告)日：1996-01-09
申请号：US359484
申请日：1994-12-20
CPC分类号： H01Q1/1271
摘要： An automotive antenna system for receiving FM broadcast band radio signals includes a conformal antenna and a glazing panel having an electrically conductive coating. A conductive trace integrated with a front windshield panel, for example, forms an active slot antenna which is connected by a coaxial cable to the automobile's FM radio receiver. A transparent conductive layer is applied over a substantial portion of the rear window opening which is typically dimensioned such that it would otherwise be resonant within the FM broadcast band and parasitically coupled to the active antenna, which would cause the active antenna to have an undesirable directional pattern. The transparent layer has a sufficiently high conductivity and is applied over a sufficiently large portion of the resonant window opening to substantially reduce or eliminate resonances within the FM broadcast band.
摘要翻译： 用于接收FM广播频带无线电信号的汽车天线系统包括保形天线和具有导电涂层的玻璃面板。 例如，与前挡风玻璃面板集成的导电迹线形成有源缝隙天线，其通过同轴电缆连接到汽车的FM无线电接收器。 透明导电层被施加在后窗开口的大部分上，该窗口的尺寸通常被设计成使得它将在FM广播频带内共振并且寄生耦合到有源天线，这将导致有源天线具有不期望的方向 模式。 透明层具有足够高的导电性并且被施加在谐振窗口的足够大的部分上以基本上减少或消除FM广播频带内的谐振。
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