- What is the function of the mixer and local oscillator in radio receiver?
- What are the types of oscillators?
- What is the function of an oscillator?
- Which type of diode is used in radio receivers?
- What are the basic requirements of an oscillator?
- Which oscillator is used as a local oscillator in radio receiver?
- What are the types of receivers?
- What is the difference between heterodyne and superheterodyne?
- What is the principle of oscillator?
- What is the local oscillator frequency?
- How do you choose a local oscillator frequency?
- What is superheterodyne principle?
- What are the advantages of a superheterodyne receiver?
- What is called oscillation?
- What is the name of radio receiver?
- What are the parts of radio receiver?
- How does an oscillator work without input?
- How does a local oscillator work?
What is the function of the mixer and local oscillator in radio receiver?
Figure 1: The basic superheterodyne architecture mixes the RF signal with a local oscillator at a fixed offset from the amplified RF signal to be tuned to develop a down-converted, fixed-frequency IF signal that can then be amplified and demodulated to baseband.
The mixer, a nonlinear stage, combines the two signals..
What are the types of oscillators?
Types of Oscillators: Common oscillator technology variationsCrystal Oscillators.SAW oscillators.MEMS Oscillators.Voltage-controlled oscillators.Voltage-controlled oscillators can operate at higher frequencies but are much less stable than other oscillator signals.
What is the function of an oscillator?
An electronic oscillator is an electronic circuit that produces a periodic, oscillating electronic signal, often a sine wave or a square wave. Oscillators convert direct current (DC) from a power supply to an alternating current (AC) signal.
Which type of diode is used in radio receivers?
varactor diodesIn radio receivers, varactor diodes are used for So the diodes are used for tuning at the receivers. Varactor diodes operate when they are reverse-biased. Varactor diodes are often used in RF circuits. They are used in voltage controlled oscillators in a phase locked loop.
What are the basic requirements of an oscillator?
Let us consider the basic requirement of oscillator circuit.First, amplification is required to provide the necessary gain for the signal.Second, sufficient regenerative feedback is required to sustain oscillations.Third, a frequency determining device is needed to maintain the desired output frequency.
Which oscillator is used as a local oscillator in radio receiver?
Explanation: Oscillator which is used as a local oscillator in radio receiver is generally a tuned circuit. This tuned circuit consists of inductors and capacitors to determine the resonant frequency, therefore it is an LC tuned circuit.
What are the types of receivers?
The most common types of receiver are administrative receiver (see paragraph 56.2. 3), fixed charge receiver (see paragraph 56.2. 4), Law of Property Act receiver (see paragraph 56.2. 5), court appointed receiver (see paragraph 56.2.
What is the difference between heterodyne and superheterodyne?
A superheterodyne receiver contains a combination of amplification with frequency mixing, and is by far the most popular architecture for a microwave receiver. To heterodyne means to mix two signals of different frequencies together, resulting in a “beat” frequency.
What is the principle of oscillator?
There are many types of electronic oscillators, but they all operate according to the same basic principle: an oscillator always employs a sensitive amplifier whose output is fed back to the input in phase. Thus, the signal regenerates and sustains itself. This is known as positive feedback.
What is the local oscillator frequency?
The r.f. circuits and the local oscillator are all tuned by varactor diodes. The tuning range is from 470−860 MHz. At these frequencies, the circuit Q s are relatively low, with values of about 30 at 600 MHz.
How do you choose a local oscillator frequency?
It generally ranges from 88 to 108 MHz (a 20 MHz span) and the Intermediate Frequency (IF) is chosen to be at 10.7 MHz (slightly higher than twice the range of 20 MHz). With an IF of 10.7 MHz the local oscillator (LO) can be 10.7MHz lower (or higher) than the signal to be received.
What is superheterodyne principle?
In the Superheterodyne Principle, the incoming signal voltage is combined with a signal generated in the receiver. … This local oscillator voltage is normally converted into a signal of a lower fixed frequency.
What are the advantages of a superheterodyne receiver?
The superheterodyne receiver offers superior sensitivity, frequency stability and selectivity. Compared with the tuned radio frequency receiver (TRF) design, superhets offer better stability because a tuneable oscillator is more easily realized than a tuneable amplifier.
What is called oscillation?
Oscillation is the repetitive variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states. … Familiar examples of oscillation include a swinging pendulum and alternating current.
What is the name of radio receiver?
In radio communications, a radio receiver, also known as a receiver, a wireless or simply a radio, is an electronic device that receives radio waves and converts the information carried by them to a usable form. It is used with an antenna.
What are the parts of radio receiver?
Two components are required for radio communication: a transmitter and a receiver….Radio receiversAntenna: Captures the radio waves. … RF amplifier: A sensitive amplifier that amplifies the very weak radio frequency (RF) signal from the antenna so that the signal can be processed by the tuner.More items…
How does an oscillator work without input?
An oscillator does not require any external input signal to produce sinusoidal or other repetitive waveforms of desired magnitude and frequency at the output and even without use of any mechanical moving parts. … An oscillator circuit uses a vacuum tube or a transistor to generate an AC output.
How does a local oscillator work?
In electronics, a local oscillator (LO) is an electronic oscillator used with a mixer to change the frequency of a signal. This frequency conversion process, also called heterodyning, produces the sum and difference frequencies from the frequency of the local oscillator and frequency of the input signal.