公开(公告)号：US4991227A

公开(公告)日：1991-02-05

申请号：US141853

申请日：1988-01-11

申请人： Walter H. Kehler, Jr.

发明人： Walter H. Kehler, Jr.

IPC分类号： H03G3/34 ,  H04B1/10

CPC分类号： H04B1/10 ,  H03G3/344

摘要： The period of time that the squelch circuit maintains a radio receiver's audio amplifier active after the signal strength of a received carrier fades below a threshold level is inversely proportional to the strength of the received carrier immediately before the fade. This threshold level is also variable. If, immediately before the fade, the received signal strength exceeds a predetermined trigger level (Vtrg) the threshold level is raised. A buffer amplifier (102) charges a capacitor (C) to a voltage which is proportional to the strength of a received carrier. If the carrier fades below a threshold (Vth2 or Vth3, the buffer is disabled and the capacitor slowly discharges through a resistor (R). When the voltage at the capacitor crosses a reference voltage (Vref1) the output of a comparator (104) switches, thereby deactivating the receiver's audio amplifier. If the voltage at the buffer output is within a specified range, a feedback control circuit (112) switches a variable hysteresis feedback circuit (110) such that the negative-going threshold of the comparator (106) is switched from one threshold level (Vth2) to another (Vth3).

摘要翻译： 在接收到的载波的信号强度衰落到阈值以下之前，静噪电路维持无线电接收机的音频放大器有效的时间与紧接在衰落之前的接收到的载波的强度成反比。 该阈值水平也是可变的。 如果在衰减之前，接收到的信号强度超过预定的触发电平（Vtrg），则阈值电平升高。 缓冲放大器（102）将电容器（C）充电到与所接收的载体的强度成比例的电压。 如果载波衰减到阈值以下（Vth2或Vth3，缓冲器被禁止，电容器通过电阻器（R）缓慢放电，当电容器的电压跨过参考电压（Vref1）时，比较器（104）的输出开关 如果缓冲器输出端的电压在规定的范围内，则反馈控制电路（112）切换可变滞后反馈电路（110），使得比较器（106）的负向阈值 从一个阈值电平（Vth2）切换到另一个（Vth3）。

公开(公告)号：US6157260A

公开(公告)日：2000-12-05

申请号：US260306

申请日：1999-03-02

申请人： Keith A. Tilley ,  Rajesh H. Zele ,  Walter H. Kehler, Jr.

发明人： Keith A. Tilley ,  Rajesh H. Zele ,  Walter H. Kehler, Jr.

IPC分类号： H03J7/04 ,  H03L7/14 ,  H03L7/00

CPC分类号： H03J7/04 ,  H03J2200/29 ,  H03L7/146

摘要： A receiver includes a main loop (222) having a main VCO (210) and a secondary loop (224) having a secondary VCO (216). The receiver momentarily phase locks an incoming RF signal (228), and then samples and stores a correction voltage (240) being applied to the main VCO (210). The main loop (222) is then put into a non-phase locked mode of operation and the stored correction voltage is applied through a receive automatic tuning circuit (218) to the main VCO (210) for the duration of the incoming RF signal (228). This effectively calibrates the LO frequency (230) of the receiver to the incoming RF signal frequency (228).

公开(公告)号：US4968952A

公开(公告)日：1990-11-06

申请号：US360627

申请日：1989-06-02

申请人： Walter H. Kehler, Jr.

发明人： Walter H. Kehler, Jr.

IPC分类号： H03B5/12 ,  H03L20060101 ,  H03L1/00 ,  H03L5/00 ,  H03L7/00

CPC分类号： H03L5/00 ,  H03B5/1203 ,  H03B5/1231 ,  H03B5/1243 ,  H03B5/1296 ,  H03L1/00 ,  H03B2200/0062 ,  H03B2200/0088 ,  H03B2200/009

摘要： An automatic voltage-controlled oscillator (VCO) current control circuit, that senses a voltage in the VCO representative of the current of the VCO, compares that voltage to a reference voltage, and applies the voltage resulting from that comparison back to the VCO at a point therein that changes its bias state in such a manner as to maintain the noise level in the VCO at a minimum and also maintains the power output of the oscillator substantially constant.

摘要翻译： 检测表示VCO电流的VCO中的电压的自动压控振荡器（VCO）电流控制电路将该电压与参考电压进行比较，并将该比较产生的电压反馈到VCO 在其中改变其偏置状态，使得将VCO中的噪声电平保持在最小，并且还保持振荡器的功率输出基本恒定。

公开(公告)号：US06414554B1

公开(公告)日：2002-07-02

申请号：US09820232

申请日：2000-03-23

申请人： Keith A. Tilley ,  Rajesh H. Zele ,  Walter H. Kehler, Jr.

发明人： Keith A. Tilley ,  Rajesh H. Zele ,  Walter H. Kehler, Jr.

IPC分类号： H03L700

CPC分类号： H03J7/04 ,  H03J2200/29 ,  H03L7/146

摘要： A receiver includes a main loop (222) having a main VCO (210) and a secondary loop (224) having a secondary VCO (216). The receiver momentarily phase locks an incoming RF signal (228), and then samples and stores a correction voltage (240) being applied to the main VCO (210). The main loop (222) is then put into a non-phase locked mode of operation and the stored correction voltage is applied through a receive automatic tuning circuit (218) to the main VCO (210) for the duration of the incoming RF signal (228). This effectively calibrates the LO frequency (230) of the receiver to the incoming RF signal frequency (228).

摘要翻译： 接收机包括具有主VCO（210）和具有次级VCO（216）的次级环路（224）的主回路（222）。 接收机瞬间锁定进入的RF信号（228），然后采样并存储施加到主VCO（210）的校正电压（240）。 然后，主回路（222）进入非相位锁定操作模式，并且存储的校正电压通过接收自动调谐电路（218）施加到主VCO（210），以进入RF信号的持续时间 228）。 这有效地校准接收机的LO频率（230）到输入RF信号频率（228）。

公开(公告)号：US5454118A

公开(公告)日：1995-09-26

申请号：US219248

申请日：1994-03-28

申请人： John W. Simmons ,  Walter H. Kehler, Jr.

发明人： John W. Simmons ,  Walter H. Kehler, Jr.

IPC分类号： H03G3/34 ,  H04B1/10

CPC分类号： H03G3/344 ,  H04B1/1027

摘要： A squelch circuit (118) is provided having a squelch hysteresis window for preventing squelch chatter in a communication device (100). The communication device (100) includes a plurality of squelch states. The squelch circuit (118) comprises a first means (206) for sensing when the communication device (100) is in a first squelch state. The squelch circuit (118) also includes a second means (116) which is responsive to the first means (206) for varying the squelch hysteresis window to prevent squelch chatter.

摘要翻译： 提供了一种静噪电路（118），具有用于防止通信装置（100）中的静噪颤动的静噪窗口。 通信装置（100）包括多个静噪状态。 静噪电路（118）包括用于感测何时通信装置（100）处于第一静噪状态的第一装置（206）。 静噪电路（118）还包括第二装置（116），其响应于第一装置（206）来改变静噪窗口以防止静噪颤动。