0
To isolate the bias circuitry of the transistor from the feedback network with RF currents.
Wiki User
∙ 13y ago
Add your answer:
Earn +20 pts
What type of inductor is installed in a circuit to impede the flow of ac of a frequency?
A: The inductor is called a RF choke
What are the applications of hartley oscillator?
hartley oscillators are mainly used in radio receivers. Also note that due to its wide range of frequencies it is the most popular oscilator
What are the principles of mixing in electronic communications?
In receivers the received RF signal is mixed with the signal of a local oscillator of a different frequency and the intermediate frequency is then amplified by the IF stages normally 3 that resonate slightly off beat to filter out all harmonics and is then detected by the detector stage where all RF is filtered down to ground and only pure audio is then amplified In receivers the received RF signal is mixed with the signal of a local oscillator of a different frequency and the intermediate frequency is then amplified by the IF stages normally 3 that resonate slightly off beat to filter out all harmonics and is then detected by the detector stage where all RF is filtered down to ground and only pure audio is then amplified
Why is radio frequeny choke used in high level modulating circuit?
Because the output circuits of the modulator would otherwise present an impedance to the RF amplifier in parallel with the transmission line and antenna system, which you don't want. In other words, you want the RF all going up the tower, not down to ground through the modulator.
What is the purpose of a local oscillator in mixer?
A local oscillator is a device that generates a sinusoidal signal with a frequency such that the receiver is able to generate the correct resulting frequency, or intermediate frequency (IF), for further amplification and conversion into audio detection. There is one local oscillator in a single conversion super heterodyne receiver where heterodyning or mixing is used to generate beat frequencies, which may be the sum or the difference of two frequencies. The local oscillator is usually adjustable and in step with the increment or decrement in the receiver frequency. For instance, if the receiver is tuned to 1,455 kilohertz (kHz) as radio frequency input (RF-in), the local oscillator frequency (LOF) may be set to 1,910 kHz for a so-called high side injection. The two signals are fed to an electronic device known as the mixer, which derives LOF - RF-in = IF or 455 kHz, which suggests why amplitude modulation (AM) broadcast receivers have about four stages of low-power amplifiers tuneable to 455 kHz.
Why transistor is used?
for high frequency applications(RF oscillator) we use BF 194
Where is the transistor BF194 used?
for high frequency applications(RF oscillator) we use BF 194
Why is your RF modulator not working?
You need to describe symptoms. Check oscillator frequency and power supply.
What section of a transmitter impresses the audio information on the radio wave?
AF modulator. Audio signals produced by the microphone get amplified enough with the power to modulate the RF carrier wave generated by a RF oscillator.
What is proximitor?
A proximitor is an electronic device that generates a radio frequency (RF) signal using an oscillator circuit. It also processes the RF signal to extract usable data using a demodulator circuit. A proximitor is often used in conjunction with a proximity probe to measure the displacement of a target surface.
Why IF frequencies used rather than RF frequencies?
IF frequencies are used rather than RF frequencies because it is easier to design a bandpass amplifier that is tuned to a specific frequency range than one that is variably tuned during operation. This is the basis behind the superheterodyne design. The local oscillator is the only thing that is tuned in the RF stage. Everything else is wider band and relatively fixed. Also, circuit design at RF frequencies is more prone to parasitic capacitance and inductance, making the task more complex.
What type of inductor is installed in a circuit to impede the flow of ac of a frequency?
A: The inductor is called a RF choke
Block diagram of FM transmitter?
very rough: +---+ |##| +---+
What is difference between series fed and shunt fed hartley oscillator?
The DC voltage for the amplifier (transistor or FET) runs for a series-fed oscillator through the inductance of the LC circuit. A shunt-fed oscillator uses a radio-frequency choke or a resistor to deliver DC voltage to the amplifier. For an oscillator the difference between serial-fed and shunt-fed is small. The choke resonance frequency can interact with the LC circuit resonance frequency. This problem happens only with shunt-fed. Furthermore series-fed needs less components. Therefore it is prefered for (low power) oscillators. The output circuit of an amp can be series-fed or shunt-fed, too. The additional DC current through the coil will drive a iron or ferrite core earlier into saturation. This is an disadvantage of serial-fed. At a high-voltage tube RF amp with say 2000V DC voltage, in the shunt-fed amp only the choke and the DC blocking capacity have to withstand the high voltage. This is an advantage of the shunt-fed solution.
What are the applications of hartley oscillator?
hartley oscillators are mainly used in radio receivers. Also note that due to its wide range of frequencies it is the most popular oscilator
What has the author Andrei Grebennikov written?
Andrei Grebennikov has written: 'RF and Microwave Transistor Oscillator Design' 'RF and microwave power amplifiers and oscillators' -- subject(s): Microwave Oscillators, Microwave amplifiers, Power amplifiers, Radio frequency oscillators
What is rf input in physics?
RF is used as an abbreviation of "radio frequency".
