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1.
公开(公告)号:US06370365B1
公开(公告)日:2002-04-09
申请号:US09205312
申请日:1998-12-04
IPC分类号: H04B104
摘要: A selective call radio (300) includes receiver (200). The receiver in turn includes an antenna (202) for receiving a radio signal having a first operating frequency, an amplifier(204) coupled thereto for generating an amplified signal; and a frequency translation circuit (208). The frequency translation circuit includes a selectivity filter (212) and an integrated frequency conversion circuit (216). The selectivity is coupled to the amplified signal for generating a filtered signal. The integrated frequency conversion circuit is coupled to the filtered signal and is incorporated into at least one IC (integrated circuit). The integrated frequency conversion circuit includes an oscillator (220), a divider (224), and a mixer (218). A first input of the mixer is coupled to the filtered signal generated by the selectivity filter. The divider is coupled to the oscillator and its output is coupled to a second input of the mixer. The mixer generates an output signal having a second operating frequency, the second operating frequency having a frequency value different from the frequency value of the first operating frequency of the radio signal.
摘要翻译: 选呼通话(300)包括接收机(200)。 接收机又包括用于接收具有第一工作频率的无线电信号的天线(202),与其耦合的放大器(204),用于产生放大信号; 和频率转换电路(208)。 频率转换电路包括选择性滤波器(212)和集成频率转换电路(216)。 选择性耦合到放大的信号以产生滤波信号。 集成频率转换电路耦合到滤波后的信号,并被并入到至少一个IC(集成电路)中。 集成频率转换电路包括振荡器(220),分频器(224)和混频器(218)。 混频器的第一输入端耦合到由选择滤波器产生的滤波信号。 分频器耦合到振荡器,其输出耦合到混频器的第二输入端。 混频器产生具有第二工作频率的输出信号,第二工作频率具有与无线电信号的第一工作频率的频率值不同的频率值。
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公开(公告)号:US5844448A
公开(公告)日:1998-12-01
申请号:US928162
申请日:1997-09-12
CPC分类号: H03L3/00 , H03K3/014 , H03K3/0307 , H03B2200/004 , H03B5/368
摘要: An oscillator circuit (10) having an optimized start up time includes an inverting amplifier (12) coupled in parallel to a crystal (14), a first bank of capacitors (16) coupled to the crystal, and a second bank of capacitors (20) switchably coupled (18) in parallel to the frequency resonant network, wherein the second bank of capacitors has a higher capacitance load than the first bank of capacitors. The oscillator circuit may also include a processor (62) for controlling when the second bank of capacitors gets switched and coupled to the crystal.
摘要翻译: 具有优化的启动时间的振荡器电路(10)包括与晶体(14)并联耦合的反相放大器(12),耦合到晶体的第一组电容器(16)和第二组电容器(20) )与所述频率共振网络并联地切换耦合(18),其中所述第二组电容器具有比所述第一组电容器更高的电容负载。 振荡器电路还可以包括用于控制何时第二组电容器被切换并耦合到晶体的处理器(62)。
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