Varactors

[bradleytron]

Greetings everyone,

Does anyone know if varactors can be cascaded to increase the effective capacitance range and what, if any, shortfalls will result.

Thanks. 

[amspire]

You put them in parallel to increase the capacitance, but there is no reason why it shouldn't work. If you don't need as much range as a typical varicap, you can use an ordinary diode or transistor junction. This means you can just use devices with a much higher capacitance. The varicaps are optimized for range and Q factor. Mosfets with the gate shorted to the source can have drain-source capacitances in the hundreds to thousands of pF and this capacitance will change with applied voltage.

[bradleytron]

Thanks, I'll do some experimentation.