公开(公告)号：US09048920B2

公开(公告)日：2015-06-02

申请号：US14389259

申请日：2012-03-30

申请人： Chow Loong Cheah ,  Kar Boon Oung ,  V. C. Prakash V K Chacko

发明人： Chow Loong Cheah ,  Kar Boon Oung ,  V. C. Prakash V K Chacko

IPC分类号： H04B1/10 ,  H04B1/12

CPC分类号： H04B1/123 ,  H03D7/165 ,  H03D7/18 ,  H04B1/10 ,  H04B1/30 ,  H04B2001/305

摘要： An apparatus and method for reducing FM audio artifacts in a receiver are provided. A direct conversion radio frequency (RF) receiver converts an analog FM signal into a phase shifted digital low IF signal. A digital controller coupled to the analog FM receiver provides adaptive frequency translation for different channel spacing and provides adaptive low IF configuration through the different channel spacing, thereby suppressing audio artifacts.

摘要翻译： 提供了用于减少接收机中的FM音频伪像的装置和方法。 直接转换射频（RF）接收机将模拟FM信号转换为相移数字低IF信号。 耦合到模拟FM接收机的数字控制器为不同的信道间隔提供自适应频率转换，并通过不同的信道间隔提供自适应低IF配置，从而抑制音频伪像。

公开(公告)号：US20080166978A1

公开(公告)日：2008-07-10

申请号：US11621735

申请日：2007-01-10

申请人： CHOW LOONG CHEAH ,  SIEW YIN LEE ,  VC PRAKASH VK CHACKO

发明人： CHOW LOONG CHEAH ,  SIEW YIN LEE ,  VC PRAKASH VK CHACKO

IPC分类号： H04B1/40 ,  H04B1/12

CPC分类号： H04B1/28

摘要： A circuit (100) comprising an antenna (105) for receiving a carrier signal modulated by a data signal, a direct conversion receiver (180) for receiving the modulated carrier signal, a signal generator circuit (140, 145, 150) arranged to generate a mixing signal having a frequency substantially the same as the carrier signal, a mixing module (125i, 125q) having an in-phase and a quadrature phase signal path (120i, 120q) arranged to mix the mixing signal at different phases with the received modulated carrier signal in order to generate an in-phase and a quadrature baseband signal, a frequency offset circuit (155, 200) arranged to generate an offset signal having a frequency offset from the frequency of the carrier signal, a coupling circuit (170a, 170b, 170c) arranged to selectively decouple the antenna from the direct conversion receiver and to couple the offset signal to the mixing module in order to generate a baseband test signal in the in-phase and quadrature signal paths for determining an imbalance in the amplitudes of the baseband test signals between the in-phase and quadrature signal paths.

摘要翻译： 一种电路（100），包括用于接收由数据信号调制的载波信号的天线（105），用于接收经调制的载波信号的直接转换接收机（180），被配置为产生 具有与载波信号基本相同的频率的混频信号，具有同相和正交相位信号路径（120i，120q）的混频模块（125i，125q），被配置为混合不同的混频信号 相位与所接收的调制载波信号相乘以产生同相和正交基带信号;频率偏移电路（155,200），被布置为产生具有从载波信号的频率偏移的偏移信号;耦合 电路（170a，170b，170c），被布置成选择性地将天线与直接转换接收器分离并将偏移信号耦合到混合模块，以便在同相和正交信号中产生基带测试信号 用于确定同相和正交信号路径之间的基带测试信号的幅度不平衡的通路。

公开(公告)号：US07860196B2

公开(公告)日：2010-12-28

申请号：US11621735

申请日：2007-01-10

申请人： Chow Loong Cheah ,  Siew Yin Lee ,  Vc Prakash Vk Chacko

发明人： Chow Loong Cheah ,  Siew Yin Lee ,  Vc Prakash Vk Chacko

IPC分类号： H04L27/06 ,  H04B1/40

CPC分类号： H04B1/28

摘要： A method and circuit are described for estimating I and Q amplitude imbalance occurring in a signal received by a direct conversion receiver (DCR). The DCR generates a mixing signal having a frequency substantially the same as the carrier signal of the signal received by an antenna. A mixing module mixes the mixing signal at different phases with the received signal to generate I and Q baseband signals. A frequency offset circuit generates an offset signal having a frequency offset from the carrier signal frequency. A coupling circuit selectively decouples the antenna from the DCR and couples the offset signal to the mixing module to generate a baseband test signal in the I and Q signal paths for determining an imbalance in the amplitudes of the baseband test signals between the I and Q signal paths.

摘要翻译： 描述了用于估计由直接转换接收机（DCR）接收的信号中发生的I和Q振幅不平衡的方法和电路。 DCR产生具有与由天线接收的信号的载波信号基本相同的频率的混频信号。 混合模块将不同相位的混频信号与接收信号进行混合，以产生I和Q基带信号。 频率偏移电路产生具有与载波信号频率的频率偏移的偏移信号。 耦合电路选择性地将天线与DCR分离，并将偏移信号耦合到混合模块，以在I和Q信号路径中产生基带测试信号，以确定I和Q信号之间的基带测试信号幅度的不平衡 路径。

公开(公告)号：US06397049B1

公开(公告)日：2002-05-28

申请号：US09431376

申请日：1999-11-01

申请人： Siew Yin Lee ,  Chow Loong Cheah

发明人： Siew Yin Lee ,  Chow Loong Cheah

IPC分类号： H04B110

CPC分类号： H03G3/34

摘要： A two-way radio (1) that has a radio frequency receiver (2) having a modulated radio frequency signal output and a variable bandwidth filter (3) with an input coupled to the modulated radio frequency signal output. The radio (1) also has demodulator circuitry (4), a speaker (6) and processing circuitry (5). In use when the radio (1) is operating in squelch mode, the processing circuitry (5) controls the variable bandwidth filter (3) to have a first bandwidth and when in unsquelch mode the processing circuitry (5) controls the variable bandwidth filter (3) to have a second bandwidth which has a smaller frequency range and the first bandwidth.

摘要翻译： 一种具有调制射频信号输出的射频接收机（2）和可变带宽滤波器（3）的双向无线电（1），其具有耦合到调制的射频信号输出的输入。 无线电（1）还具有解调器电路（4），扬声器（6）和处理电路（5）。 在无线电（1）以静噪模式工作时，在使用中，处理电路（5）控制可变带宽滤波器（3）具有第一带宽，并且当处于非校验模式时，处理电路（5）控制可变带宽滤波器 3）具有具有较小频率范围和第一带宽的第二带宽。