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Article: Antenna switches: MEMS wait in the wings. (Cover Story).
- Article from:
- EDN Europe
- Article date:
- April 1, 2002
- Author:
CopyrightCOPYRIGHT 2002 Reed Business Information, Inc. (US). This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Rf-signal switching's primary application in cell-phone-handset designs is the antenna transmit/receive switch. to meet future performance demands, you may need to replicate Rf switching at other stages in the Rf-signal path and shift toward micro-fabricated electromechanical switches.
THE BASIC OPERATION of an antenna switch is simple enough: You connect the antenna to the output of the power amplifier and disconnect it from the receiver's LNA input when the transceiver is in transmit mode, and vice-versa for receive mode. Conventionally, switches based on PIN diodes or FETs have provided this function; with the handset's host processor controlling the switches ...