Transmitter produced intermodulation interference is the result of one or more transmitters impressing a signal in the non-linear final output stage circuitry of another transmitter, usually via antenna coupling. The intermod product frequency is then re-radiated from the transmitter’s antenna.

What is meant by intermodulation?

Definition of intermodulation : the production in an electrical device of currents having frequencies equal to the sums and differences of frequencies supplied to the device or of their harmonics.

What do you mean by inter modulation distortion?

Intermodulation Distortion (IMD): When two signals mix in non-linear circuits or devices, new frequency components are created that are not in the original signal. The resulting signal error is called intermodulation distortion, or IMD. Synonyms. IM.

What is intermodulation in FDMA?

Intermodulation distortion occurs when many carriers access a non-linear satellite transponder. In this paper, the satellite C/I ratio is investigated when the transponder is accessed by many small carriers in the presence of a dominant carrier. A lower bound C/I ratio and an optimum input backoff point are deduced.

Where does intermodulation occur?

Intermodulation can occur between closely spaced transmitters, whereby the signal radiated from one transmitter generates IM products in the output stage of other nearby transmitters. The IM products are then transmitted along with the tuned carrier frequencies of the affected transmitters.

What is meant by intermodulation noise?

Filters. Noise that is the result of modulation, demodulation, and any nonlinear characteristics of the transmission medium or transmission system components.

Why does intermodulation distortion occur?

Intermodulation Distortion (IMD) occurs when two or more signals are used in a non-linear system. The spectrum at the output of the non-linear device will not only consist of the original signals but will also contain the sum and difference of the input signals along with their harmonics.

What causes intermodulation products?

Single-channel intermodulation product: the intermodulation products are caused by the non-linearity in transmitter amplifier circuits and passive devices. Multi-channel intermodulation product: the signals in the different channels interfere together to produce multi-channel intermodulation products.

How can intermodulation products be prevented?

How to prevent Intermodulation

1. Use high quality components and avoid non-linear active components in design of devices.
2. Operate power amplifiers in linear range to avoid intermodulation components.
3. Avoid low quality mechanical switches and poor contact signal adaptors.

What is intermodulation distortion and how does it occur?

Intermodulation distortion is defined as the production of new output signals which are created from the nonlinear combination of two or more input signals. This intermodulation occurs because of the nonlinearity in the amplification process.

What are the causes of intermodulation in computer networks?

Intermodulation is caused by non-linear behaviour of the signal processing (physical equipment or even algorithms) being used.

What is the effect of signal amplitudes on intermodulation?

The higher the signal amplitudes, the more pronounced the effect of the nonlinearities, and the more prominent the intermodulation that occurs — even though upon initial inspection, the system would appear to be linear and unable to generate intermodulation.

What is the difference between thermal noise and intermodulation noise?

Intermodulation noise differs from thermal noise since it is a function of the signal power at the point of non-linearity. Intermodulation distortion comes about due to the presence of non-linearities in an electronic system as well.1 Take for instance the triode transfer characteristic illustrated in Figure 4.1.