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What is meant by local oscillator?
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.
What is the output of local oscillator?
10.6. The inputs to the mixer are the signal at the radio frequency and the sinusoid from a local oscillator (LO). The output is the signal at the intermediate frequency. Mixing is the process of multiplying the RF signal by the local oscillator and then low-pass filtering the product.
What is local oscillator in superheterodyne receiver?
The local oscillator is the heart of the receiver. It is the most critical circuit in the entire receiver because any drift or instability in the local oscillator will translate into drift and instability in the received signal.
Why local oscillator frequency is higher?
As a listener tunes across the broadcast band, the local oscillator is also tuned in synchronism so as to precisely produce a single-frequency signal (essentially an unmodulated carrier signal) which is higher in frequency by 455 kHz in comparison to the incoming signal.
Which oscillator is used in radio receivers is?
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. Out of the four options, only Hartley Oscillator has an LC resonant tank circuit.
What is superheterodyne principle?
The superheterodyne receiver is the most common configuration for radio communication. Its basic principle of operation is the translation of all received channels to an intermediate frequency (IF) band where the weak input signal is amplified before being applied to a detector.
What is the advantage of Superheterodyning *?
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 are the main uses of an oscillator?
Some common applications of oscillators include: Quartz watches (which uses a crystal oscillator) Used in various audio systems and video systems Used in various radio, TV, and other communication devices Used in computers, metal detectors, stun guns, inverters, ultrasonic and radio frequency applications. Used to generate clock pulses for microprocessors and micro-controllers
What is the purpose of a local oscillator in mixer?
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.
What is the most stable oscillator?
The type of oscillator is most stable in simple circuit is Crystalline oscillator.
How oscillators are classified?
The oscillators are classified into several types based on various factors like nature of waveform, range of frequency, the parameters used, etc. The following is a broad classification of oscillators. According to the Waveform Generated. Based on the output waveform, oscillators are classified as sinusoidal oscillators and non-sinusoidal oscillators.