| 摘要 |
PURPOSE: A transmitting/receiving apparatus in a WLL(Wireless Local Loop) terminal is provided to reduce the deviation between transmitting/receiving band channels and minimize the loss of transmitting channels by reducing the number of components in an RF transmitting unit and selectively filtering the bands of transmitting and receiving channels. CONSTITUTION: A transmitting/receiving apparatus in a WLL terminal is comprised of a band select control part(100), an RF transmitting unit(200), a dual band duplexer part(300), and an RF receiving unit(400). The band select control part(100) outputs a low signal to a band pass filter(220) and the dual band duplexer part(300) if all the bands of transmitting/receiving signals are low bands. In case that all the bands of transmitting/receiving signals are high bands, the band select control part(100) outputs a high signal to the band pass filter(220) and the dual band duplexer part(300). The RF transmitting unit(200) contains an up converter(210), the band pass filter(220), a driving amplifier(230), a power amplifier(240), and an isolator(250). If a transmitting path and a receiving path are determined by a band select signal outputted from the band select control part(100), the dual band duplexer part(300) receives an RF transmitting signal from the isolator(250) and transmits only the determined band through an antenna. Also the dual band duplexer part(300) receives an RF receiving signal from the antenna and passes only the determined band to the RF receiving unit(400). The RF receiving unit(400) receives the RF receiving signal passed through the dual band duplexer part(300) and executes a receiving processing operation.
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