Introduction

Welcome to Intermod Assist -- Intermodulation Calculator and Frequency Coordination software.  Intermod Assist is a new, ground-breaking software tool specifically designed for the wireless, professional audio and video industries.  Intermod Assist's computational engine rapidly generates frequency sets of intermodulation distortion-free radio frequencies, applying user-defined signal bandwidths and channel spacing.  These frequency sets can be used for the purpose of frequency coordination where the goal is to assign the most reliable channels to your wireless audio and video gear -- that is, to ensure reliable operation of the wireless devices by assigning channels that are free of intermodulation interference.  

In the wireless audio industry two categories of intermodulation interference are a major concern: (1) transmitter-produced, and (2) receiver-produced.  Transmitter-produced intermodulation interference is caused by one or more transmitters that generate a signal in the non-linear, output circuitry of another transmitter -- e.g. via antenna coupling.  The intermod product frequency is then re-transmitted from the transmitter's antenna.  Receiver-produced intermodulation interference is the result of two or more transmitter signals mixing in a receiver's non-linear, RF amplifier.  The resultant intermod product frequency can interfere with other signals (of similar frequencies) that pass through the receiver.  As a result, the intermodulation distortion (IMD) phenomenon can degrade the quality of the desired signal being amplified.

Intermodulation interference is rarely desirable in wireless communication systems -- particularly in radio or audio processing.  Furthermore, it is not something that is readily measurable and avoidable (e.g. using an RF spectrum analyzer).  However, the physical basis for IMD is well understood and the mathematical formulas used to describe it are relatively simple -- so, computational methods can be applied to generate frequency sets that are free of intermodulation interference and which mitigate its effect.  If you are interested in learning more details about intermodulation distortion there are many articles and references available on the Internet.  For a good explanation we refer you to the following article: Intermodulation Performance and Measurement of Intermodulation Components.

Intermod Assist is easy to use, yet it yields very powerful results.  Below are some of the more unique features and functions that are available:

• Calculates frequency sets that are free of intermodulation interference caused by 3rd- and 5th-order intermodulation products -- in particular two transmitter 3rd-order intermod products (2Tx 3rds), three transmitter 3rd-order intermod products (3Tx 3rds), and two transmitter 5th-order intermod products (2Tx 5ths)
• Generates intermod-compatible frequency sets of varying stringencies: Strictest, Strict, Moderate, Lenient, Weak, Weaker, Weakest
• Introduces Smart Frequency Sets™ -- a new concept which combines 3 classes of frequencies within a single set and ranks them according to their susceptibility to intermodulation interference, which allows you to prioritize channel assignments
• Exports intermod-compatible frequency sets in different formats so they can be used or validated by other programs and scripts
• Validates frequency sets created either manually or by other programs
• Can generate an intermod-compatible frequency set from an RF spectrum trace that also takes into account a white space threshold that blocks-out certain frequency ranges
• Can manually lock-out certain frequency ranges within the frequency span of interest
• Reserve frequencies that are considered mandatory
• Exclude specific frequencies from the intermodulation analysis
• Ranks frequencies within a frequency set from most reliable to least reliable
• Can divide a frequency set into different Channel Bands
• Fast computations; easy-to-use interface and graphical output
• Generates PDF reports

Main View

Spectrum Trace View