Time division duplex radio communication system receivel/send linear switch circuit and its realizing method

Abstract

The circuit includes power amplifier to amplify emission signal up to emission power, circulator to couple its first port with the amplifier for exporting amplifier output power to the second port of the circulator in order to let antenna emit it, low noise amplifier to couple with circulator third port to receive signal inputted from the second port of the circulator through receiving antenna and to amplify the received signal, control unit consisting of actuating circuits for the power amplifier and the low noise amplifier to cut off the power amplifier at the time of receiving signal and to cut off the low noise amplifier at the time of emitting signal.

Description

technical field [0001] The invention belongs to the communication field, and in particular relates to a time-division duplex wireless communication system sending and receiving high-power linear switch circuit and its realization method. Background technique [0002] In recent years, mobile communication systems have begun to adopt multi-carrier technology, and the linearity required for devices used in the transmission chain is getting higher and higher. [0003] Chinese patent application 96110399.X "antenna conversion circuit and wireless communication system" discloses that an antenna conversion circuit is composed of a circulator component with 3 terminals. Among the 3 terminals, the first terminal (CTX) is connected to the transmitting circuit, the second The end (CANT) is connected to the first antenna, and the third end (CRX) can be connected to the terminal resistance through the first switch part; the second switch part can connect the third end of the circulator p...

AI Technical Summary

Problems solved by technology

However, this circuit is used for diversity receivers, and does not consider the influence of the possible instability of the power amplifier in the same-frequency time-division duplex system on the low-noise amplifier

[0004] The RF front-end of a general TDD (Time Division Duplex) system uses RF switches to control the receiving and transmitting signals. When it is high (that is, when the requirement for adjacent channel power leakage is high), it will cause the power amplifier output RF signal to pass through the RF switch. Due to the linearity of the RF switch, the out-of-band spectrum will be regenerated, so that the adjacent channel power leakage cannot meet the requirements.

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