Microwave SPDT help !!!
时间：04-04
整理：3721RD
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Hello EveryOne !
I'm simulating with ansoft designer V2 circuit simulator, a switched line phase shifter ( a very basical model ).This is the scheme :
the problem is :
SPDTs has v1=2V and V2=4V.
When SPDTs switch on the upper line (Vctrl < v1 and Vctrl=0) the phase shifter doesn't work ! But if i set the SPDT Ron a very small value ( 1e-9 ) it works perfect !
When SPDTs switch on the lower line (Vctrl > v2 and Vctrl=5V) the phase shifter doesn't work ! with lower (1e9) Ron doesn't work. With Ron equal to the Zo of the TxLine (50Ohm) it has a good S11 (measured in dB) and a very bad S21 (-144dB o.o).
How can i fix the problems ? Please, i have to write a thesis :(
I'm simulating with ansoft designer V2 circuit simulator, a switched line phase shifter ( a very basical model ).This is the scheme :
the problem is :
SPDTs has v1=2V and V2=4V.
When SPDTs switch on the upper line (Vctrl < v1 and Vctrl=0) the phase shifter doesn't work ! But if i set the SPDT Ron a very small value ( 1e-9 ) it works perfect !
When SPDTs switch on the lower line (Vctrl > v2 and Vctrl=5V) the phase shifter doesn't work ! with lower (1e9) Ron doesn't work. With Ron equal to the Zo of the TxLine (50Ohm) it has a good S11 (measured in dB) and a very bad S21 (-144dB o.o).
How can i fix the problems ? Please, i have to write a thesis :(
A realistic Ron for a good electronic RF switch would be e.g. 1 ohm (0.17 dB loss).
Yep, i know it :) But it doesn't work aniway ! However,i've solved it by replacing SPDTs with SPST :)