Diode Switch

Here is the Diode Switch test schematic, First I made a simulation of the circuit to optimice all values to the freq band I wanted.

The test circuit is constructed using a little bite of a telfon PCB with a 50 Ohm line,
I used two SMA connectors you easy connection to the network analyzer.

Here is the curve in "ON" state, (0.5dB div) The loss is only:
0.71dB at 3.5 Mhz
0.52dB at 10.7 Mhz
0.46dB at 50 Mhz

Here is the curve in "OFF" state, (10db div) The isolation is:
70dB at 3.5 Mhz
55dB at 10.7 Mhz
42dB at 50 Mhz

This Diode switch will be used to change RX/TX and to change band bank and other stuff.
A Diode switch has advantage over relay switching:
Cheap, small size, long life time, no wear, fast RX/TX, lower power usage.