Abstract:
A Doherty amplifier is provided to improve efficiency by using a different bias in a main amplifier and an auxiliary amplifier. A Doherty amplifier includes a first parallel capacitor(31), a second parallel capacitor(32), a transmission line unit(33b), and a matching network unit(35). A first parallel capacitor is connected in parallel to a main amplifier(10). The second parallel capacitor is connected in parallel to an auxiliary amplifier(20). The first and second parallel capacitors are grounded. The transmission line unit connects the main amplifier and the auxiliary amplifier. The transmission line unit is one of an inductor and a microstrip transmission line. The matching network unit is diverged between the second parallel capacitor and the transmission line unit.
Abstract:
평형형전력증폭장치및 방법가제공된다. 90도하이브리드분배기는입력신호를 90도의위상차를갖는제1 PA 입력신호및 제2 PA 입력신호로분리한다. 제1 PA 입력신호및 제2 PA 입력신호는각각제1 PA 및제2 PA에의해증폭된다. 상기의증폭에의해생성된제1 PA 출력신호및 제2 PA 출력신호는 90도하이브리드결합기에서결합된다. 90도하이브리드분배기및 90도하이브리드결합기는집중소자를이용하는브랜치-라인결합기를포함한다.
Abstract:
본발명은다중대역적층형안테나에관한것으로, 본발명의다중대역적층형안테나는급전을위한급전부와, 상기급전부에접촉하고있으며, 제1 안테나패턴을구비하는하층기판, 상기하층기판과소정간격으로이격되어적층되고, 내부에는소정모양의빈 공간을가지며, 두께에따라상기안테나의대역폭이변동되는중층기판및 상기중층기판과소정간격으로이격되어적층되고, 제2 안테나패턴을구비하는상층기판을구비하는것을특징으로한다. 본발명에따르면, 안테나캐리어가서로다른유전율을가지는다수개의층으로적층된구조를가지도록구성되므로안테나의크기를소형화시킬수 있고, 원하는대역폭에서향상된방사성능을가지도록구현할수 있다.
Abstract:
본발명의실시예들에따라 3-웨이도허티전력증폭기장치는주 증폭부, 제1 보조증폭부및 제2 보조증폭부를포함할수 있다. 3-웨이도허티전력증폭기장치의주 증폭부의주 전력용량, 제1 보조증폭부의제1 보조전력용량및 제2 보조증폭부의제2 보조전력용량이 1:m:n의상대적비율을가지고, m과 n은각각 0보다큰 실수로서동시에 1이되지않도록선택되며, 백오프(Back-off) 값이 m+n에의해결정될수 있다.
Abstract:
본발명에따른대신호용능동발룬회로는제어단자, 제1 단자및 제2 단자를가지는트랜지스터, 제1 인덕터및 제2 인덕터를포함하고, 트랜지스터는제어단자에서싱글엔디드(single-ended) 입력신호를인가받고제1 인덕터는트랜지스터의제1 단자와제1 전원전압단자사이에연결되며, 제2 인덕터는트랜지스터의제2 단자와제2 전원전압단자사이에연결됨으로써, 트랜지스터의제1 단자에반전출력신호가나타나고트랜지스터의제2 단자에비반전출력신호가나타나도록동작할수 있다.
Abstract:
본발명은 RFID(radio frequency identification) 리더기에서송신누설신호를제거하는장치및 방법에관한것이다. 송신누설신호제거장치는위상조절용오프셋부를포함하는안테나와송신경로및 수신경로를연결하는서큘레이터또는방향성결합기, 상기송신경로및 수신경로에연결되고, 상기송신경로에서발생하여상기수신경로로유입되는제1 송신누설신호및 상기안테나에서반사되어상기수신경로로유입되는제2 송신누설신호와동일한크기및 반대의위상신호를갖는누설제거신호를상기수신경로로출력하는제거부를포함한다. 본발명에따르면, RFID 시스템이사용되는모든주파수대역에서간단하게송신누설신호를제거할수 있다. 또한 RFID 시스템의외부환경이바뀌더라도송신누설신호를제거할수 있도록실시간적응방식을사용하여태그의인식율을높일수 있다.
Abstract:
An envelope tracking power amplifier according to embodiments of the present invention includes: a multi-mode bias modulator to generate a variable bias voltage using a linear amplifier and a switching amplifier operated in an envelope tracking mode or an average power tracking mode according to an operation mode control signal for determining one operation mode from the envelope tracking mode or the average power tracking mode; and a power amplifier biased according to a variable bias voltage to power-amplify and output an RF signal to an antenna. When the multi-mode bias modulator operates in the envelope tracking mode, the multi-mode bias modulator drives a linear amplification bias current corresponding to AC components of the envelope signal by the linear amplifier. The multi-mode bias modulator drives a switching amplification bias current corresponding to DC components of the envelope signal by the switching amplifier. The multi-mode bias modulator combines a linear amplification bias current with the switching amplification bias current to generate a variable bias current. When the multi-mode bias modulator operates in the average power tracking mode, the multi-mode bias modulator may drive a switching amplification bias current tracking a predetermined reference voltage by the switching amplifier to generate a variable bias current.