| 摘要 |
PURPOSE: A radio frequency switch is provided to achieve an increased degree of isolation between transmitter and receiver, while increasing the transmission signal power being transferred from the transmitter to the antenna. CONSTITUTION: A radio frequency switch comprises a power amplifying unit(10) for amplifying a transmitting RF signal having a wavelength of lambda; an antenna(T) for transmitting the transmitting RF signal to an external source, and receiving a signal from the external source; a low noise amplifying unit(50) for amplifying the signal received at the antenna; a first switching element interposed between the power amplifying unit and the antenna, and which is turned on during transmitting and off during receiving; a distributed constant line(30) constituted by a main line having a length and a plurality of auxiliary lines connected to the main line, and which controls the length of signal path by cutting the main line when the length of the main line is shorter than lambda/4, so that the signal is bypassed through one or more auxiliary lines; and a second switching element interposed between the low noise amplifying unit and a ground point, and which is turned on during transmitting and off during receiving.
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