| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To disclose techniques for compensating for second-order distortion in a wireless communication device. <P>SOLUTION: In a zero-intermediate frequency (IF) or low-IF architecture, IM2 distortion generated by a mixer results in undesirable distortion levels in the baseband output signal. A compensation circuit 104 provides a measure of the IM2 distortion current independent of the radio frequency (RF) pathway to generate an IM2 calibration current. The IM2 calibration current is combined with the baseband output signal to thereby eliminate the IM2 currents generated within the RF pathway. The calibration is provided at the factory during final testing. Instead, additional circuitry may be added to the wireless communication device to provide a pathway between the transmitter and the receiver. The transmitter signal is provided to the receiver to permit automatic calibration of the unit. An internal signal source may be used in place of the transmitter. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
