SP4T using PIN Diodes
please help me.
This circuit of SP3T switch. I think that the circuit of SP4T switch can be designed analogically.
http://images.elektroda.net/1_1331901678.jpg
And the circuit of SP4T switch can be designed by combining basic SPDT switches.
http://images.elektroda.net/37_1331901958.jpg
http://images.elektroda.net/74_1331901958.jpg
i am not getting wide bandwidth
http://images.elektroda.net/1_1331901678.jpg i think this is a good idead for 4T app. in which BW is not a problem and easy for design. but need attention for layou.
for spdt i am getting bandwidth(4-8GHz) but sp4t i am not getting. I attached schematics.
http://images.elektroda.net/12_1333104401.jpg
http://images.elektroda.net/54_1333104401.jpg
http://images.elektroda.net/57_1333104401.jpg
http://images.elektroda.net/19_1333104401.jpg
I approximately modeled circuit...
Parameters of pin-diodes were replaced by equivalent resistance and capacity.
Below results were obtained with CST
But here length connections should be minimum in field of serial connection pin-diodes.