What is a varactor diode used for?
What is a varactor diode used for?
A varactor diode is a simple variable capacitor that allows oscillator circuits and other circuits to be easily tuned by applying a voltage. These diodes have a similar structure as a p-n diode; the structure of a varactor diode is rather simple and illustrates its power as a component with nonlinear reactance.
What is the principle of varactor diode?
Definition: Varactor diode is the one which works on the principle of variation in capacitance by changing the width of the depletion region of P-N junction. The P-N Junction diode creates capacitor effect. The capacitance is controlled by applied voltage. It works on reverse biased mode.
What is output of VCO?
The VCO has an output power level of -3 dBm into 50 Ω with phase noise of -101 dBc/Hz typical at 100 kHz offset. The control voltage range is 0.4 to 2.4 volts, and load pulling is typically 0.75 MHz, pk-pk. Power supply pushing is 280 kHz/volt (typical).
Why VCO is called voltage to frequency converter?
A voltage-controlled oscillator (VCO) is one in which the frequency of oscillations varies as a function of voltage. The same circuit is also called a voltage-to-frequency converter (VFC) because a given voltage gives rise to a specific frequency.
What is varactor modulator?
Varactor diode modulator is the direct method of FM generation wherein the carrier frequency is directly varied by the modulating signal. Varactor diodes are used along with reactance modulator to provide automatic frequency correction for an FM transmitter. The varactor diode modulator circuit is shown in Fig5.
What is a varactor diode give its circuit symbol and one application?
The symbol of the Varactor diode looks like a common PN- junction diode that includes two terminals namely the cathode and the anode. And at one end this diode is inbuilt with two lines that specify the capacitor symbol.
What is a varactor diode symbol of varactor diode?
Symbol of Varactor Diode The symbol of the varactor diode is similar to that of the PN-junction diode. The diode has two terminals namely anode and cathode. The one end of a symbol consists the diode, and their other end has two parallel lines that represent the conductive plates of the capacitor.
What is a varactor diode and how is it used?
The varactor diode can be used in a variety of circuits from oscillators to filters. Knowing how to apply the control voltage is a key issue. There are many aspects to using varactor diodes in RF electronic circuits.
What does VCO stand for?
Voltage Controlled Oscillators – Tuning voltage controlled oscillator (VCO) is an oscillator whose frequency can be varied by avoltage (or current). In local oscillator applications, the VCO frequency must be able to be varied over the Rxor Tx range (quickly).
How do you implement a VCO circuit?
A VCO is implemented by replacing a fixed capacitor such as C 3 with a varactor. In another circuit that can generate a negative resistance, Figure 5 shows a bipolar transistor with an inductive reactance between the base and the ground. This common-base topology is preferred at higher frequencies.
What is a voltage controlled oscillator?
A voltage controlled oscillator (VCO) is an oscillator whose frequency can be varied by a voltage (or current). In local oscillator applications, the VCO frequency must be able to be varied over the Rx or Tx range (quickly).
