What is local oscillator leakage?

What is local oscillator leakage?

The local oscillator (LO), which drives the mixer, has leaked to the mixer’s output port. There are also other paths for the LO to leak to the system output, such as through power supplies or across the silicon itself. Regardless of how the LO leaks out, it can be referred to as LOL.

What is the function of 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.

In which type of receiver LO leakage is a serious problem and why?

DC offset errors : It is the most serious problem in the baseband section of the homodyne receivers. The cause of it is self mixing of LO leakage which is due to LO feed through to mixer input port and LNA and insufficient isolation between LO port to mixer input port and LNA input.

Why is the stability of the local oscillator important?

The performance of a signal processing system depends on the characteristics of the local oscillator. The local oscillator must remain stable in frequency. It must produce enough output power to effectively drive subsequent stages such as mixers or frequency multipliers.

What type of local oscillator is used in modern receivers?

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 is the main function of a local oscillator in case of superheterodyne receiver?

The superheterodyne receiver uses one or more mixers and local oscillators to convert the received signal channel to another frequency band for more convenient filtering and amplification.

Why local oscillator frequency is higher than signal frequency?

The reason a higher frequency is commonly chosen in a Super heterodyning receiver, is to leave more distance between the difference or intermediate frequency and the other two frequencies so that the IF signal can be more easily passed through a filter and attenuate the the original two signals.

Why local oscillator is used in superheterodyne receiver?

What is the function of local oscillator in superheterodyne receiver?

A local oscillator provides the mixing frequency; it is usually a variable frequency oscillator which is used to tune the receiver to different stations.

Why is local oscillator frequency kept higher?

The local oscillator frequency (f0) is made greater than signal frequency (Fs) in radio receiver: Hence, the 2.2:1 ratio required for the local oscillator operating above signal frequency is well within range whereas the other system has a frequency ratio of 14:1 whose capacitance are not practically available.

Why local oscillator frequency is higher?