摘要 |
Antenna switches ( 1,10 ) in dual-band or multi-band mobile phones are according to a basic idea provided with a serial semiconductor switches ( 11,21,12,22 ) per transmitting branch ( 2,3 ) and with a further semiconductor switch ( 13,23 ) coupled in parallel to a receiving branch ( 4,5,6 ), to obtain isolation between branches ( 2 - 6 ) in a simple way. Said semiconductor switches are PIN diodes or MEMS switches or pHEMT switches. Another semiconductor switch ( 14 ) coupled in parallel to the receiving branches ( 4 - 6 ) allows together with said further semiconductor ( 13 ) the introduction of elements ( 15,16 ) without a transmission line. Alternatively, the antenna switch ( 1,10 ) may comprise a transmission line ( 24,25 ), in which case the receiving branches ( 4,5,6 ) can be switched via transistor switches ( 26,27,28 ). This all improves isolation, reduces costs, complexity, size and high Radio-Frequency (RF) losses.
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