| 摘要 |
PURPOSE: An apparatus for removing an adjacent spurious frequency is provided to minimize an adjacent signal using a feedforward loop, a variable gain adjusting unit, and a phase adjusting unit. CONSTITUTION: A low noise amplifying unit(30) connects to a duplexer(20), and amplifies only original signal in a state in which a noise component of a signal is restrained for improving the strength of a receiving signal. A splitter(40) splits one path into two paths for canceling an adjacent signal among the receiving signal amplified in the low noise amplifying unit(30). A filter(50) passes the only adjacent signal among the receiving signal and restrains a receiving band signal by a band restraint characteristic. A delay element(60) equally maintains a phase delay of the signal of two paths split by the splitter(40). A variable gain adjusting unit(70) adjusts the level of the signal inputted through the filter(50). A phase adjusting unit(80) receives the signal outputted from the variable gain adjusting unit(70) and adjusts the phase of the signal. A combiner(90) combines the signal having the band restraint characteristic by the filter(50) with the signal having the delay characteristic by the delay element(60), and cancels the adjacent signal. |
