✔ Varactor Diode Resistance

Varactor Diode Resistance

- August 01, 2019

The v c is the dc voltage used for controlling the reverse voltage of the diode. The varactor diode has a non linear capacitance curve the capacitance of the varactor diode is inversely proportional to the square root of the voltage across it.

What Is Varactor Diode Construction Working

Wide Frequency Tuning In Resonant Tunneling Diode Terahertz

Varactor Multipliers

The low resistance of these varactors makes them appropriate for high q resonators in wireless system vcos to frequencies over 10 ghz.

Varactor diode resistance. C j is the junction capacitance which is dependent on the reverse bias voltage. L f is the effective inductance and it depends on the frequency limits under which a varactor diode should be operated. This means that initial changes in reverse voltage give a much greater change in capacitance than those at higher voltages.

Change of varactor diode capacitance with reverse bias. These diodes are also named as varicap diodes. Varactor diode is a one kind of semiconductor microwave solid state device and the applications of this diode mainly involve in where variable capacitance is preferred which can be accomplished by controlling voltage.

Diode resistance a p n junction diode allows electric current in one direction and blocks electric current in another direction. So varactor diode should always be operated in reverse bias. When a varactor or varicap diode is applied with a rising reverse bias potential results in an increase in the depletion width of the device which in turn causes its transition capacitance to decrease.

R r is the reverse bias resistance and r g is the geometric resistance of the varactor diode. When a reverse bias voltage is applied the electrons from n region and holes from p region moves away from the junction. As a result the width of depletion region increases and the capacitance decreases.

These diodes provide the variable resistance in the parallel resonance circuit. The varactor diode can be tuned by applying tuning voltage or bias through an isolating series resistor r1. The varactor diodes can be used to tune the filters.

Varactor diode in tunning circuit the figure below shows that d 1 and d 2 are the two varactor diode. The capacitor c1 is used to prevent the reverse bias for the varactor diode also avoids the diode getting short circuited through the inductor. It is a device whose capacitance varies with the variation in the applied reverse bias potential.

Varactor diode is a pn junction diode that is especially operated in reverse biased mode. The depletion region present in a diode acts like barrier to electric current. The smv123x series of silicon hyperabrupt junction varactor diodes are designed for use in voltage controlled oscillators vcos with a low tuning voltage operation.