Originally, before I removed it, it was placed opposite to the ground but when I read the schematic diagram it reads pointing to ground.
I broke one of its leg so I replaced it as it was placed originally (opposite to ground). According to its technical description, D8 was placed in parallel to C4 which is a part of T matching network.
So please advise me which polarity of this diode (D8) is correct or should be.
View attachment 66786
Here is the text describing the switch circuit.
E). TRANSMIT/RECEIVE SWITCH
When the radio is in the transmit mode, pin diode switches D13 and D1
are both turned on (representing less than 0.7 ohms). D13 allows the transmit
signal to pass to the antenna and D1 shorts one leg of a T matching network
(L3, L15 and C4) to ground in the receive path. This results in a parallel tuned
circuit high impedance being presented to the transmit signal so that the
receive path does not load the transmit signal. In the receive mode, both D13
and D1 are off, resulting in the antenna signal being coupled into the receive
LNA through the 50 ohm T matching network and the unwanted load of the
transmit final amplifier is reduced to less than 1 pF by D1.
I broke one of its leg so I replaced it as it was placed originally (opposite to ground). According to its technical description, D8 was placed in parallel to C4 which is a part of T matching network.
So please advise me which polarity of this diode (D8) is correct or should be.
View attachment 66786
Here is the text describing the switch circuit.
E). TRANSMIT/RECEIVE SWITCH
When the radio is in the transmit mode, pin diode switches D13 and D1
are both turned on (representing less than 0.7 ohms). D13 allows the transmit
signal to pass to the antenna and D1 shorts one leg of a T matching network
(L3, L15 and C4) to ground in the receive path. This results in a parallel tuned
circuit high impedance being presented to the transmit signal so that the
receive path does not load the transmit signal. In the receive mode, both D13
and D1 are off, resulting in the antenna signal being coupled into the receive
LNA through the 50 ohm T matching network and the unwanted load of the
transmit final amplifier is reduced to less than 1 pF by D1.
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