Meaning
Spurious signals arise from the combination of two or more frequencies in a non linear component. Intermodulation spurs appear at predictable intervals relative to the original carrier frequencies. These signals can interfere with adjacent radio channels or desensitize the receiver of the device.
Spectral Interaction
Mixing of the primary signal with unwanted interference creates new frequencies at the third and fifth order products. When multiple transmitters operate in close proximity, intermodulation spurs can clutter the available spectrum. Designers use high intercept point components to minimize the formation of these products by ensuring the amplifier stays within its linear operating range.
Receiver Sensitivity
Blockage of weak signals occurs when a spur lands directly on the frequency of a distant base station. An intermodulation spurs calculation is part of the initial link budget for any cellular or satellite module. Filtering at the input stage helps prevent strong out of band signals from entering the mixing stage.
Circuit Linearity
Characterization of the power amplifier involves measuring the ratio between the desired signal and the unwanted distortion. This measurement is conducted across the entire operating bandwidth of the device. A linear response ensures that the output remains clean even at maximum transmission power.
Engineers use this data to set the final gain parameters of the transmitter to avoid saturating the output stage.
