Intermediate Frequency Calculator | Intermediate Frequency formula

This page covers Intermediate Frequency calculator. It mentions Intermediate Frequency formula or equation. The Intermediate Frequency (IF) definition along with its benefits or advantages are also described.

What is Intermediate Frequency?

This term is widely used in electronic and communication engineering in up conversion and down conversion stages involving heterodyne architecture. It is the frequency to which carrier wave is shifted as intermediate step frequency for transmission and reception.

➨The IF (Intermediate Frequency) is generated by mixing two frequencies viz. Input frequency (F_in1 or F_in2) and Local Oscillator frequency ( F_LO1 or F_LO2).
➨F_in1 and F_LO1 are provided to RF Mixer to generate F_IF1 as sum of these two frequencies during up conversion process. Check figure-2 below.
➨F_in2 and F_LO2 are provided to RF Mixer to generate F_IF2 as difference of these two frequencies during down conversion process.

The Intermediate frequency concept is applied in RF transceivers used for various wireless systems. Refer Upconverter vs Downconverter and RF Transceiver design to understand RF Up conversion and downconversion process.

The intermediate frequency for AM receiver is 455 kHz and for FM receiver it is 10.7 MHz.

Benefits of Intermediate Frequency

Following are the benefits or advantages of Intermediate frequency.
➨Signal processing at lower frequency is easier.
➨It is easy to design filters at lower frequencies.
➨Lower frequency transistors provide higher gains.
➨It makes overall system cost cheaper due to less expensive components at lower frequencies.

Intermediate Frequency Calculator for Up converter

EXAMPLE of Intermediate Frequency calculator #1:
INPUTS:
F_in1 = 70 MHz, F_LO1= 1112.5 MHz
OUTPUT:
F_IF1 = 1182.5 MHz

Intermediate Frequency Calculator for Down converter

EXAMPLE of Intermediate Frequency calculator #2:
INPUTS:
F_in2 = 3700 MHz, F_LO2= 4680 MHz
OUTPUT:
F_IF2 = 980 MHz

The calculator#2 (for down conversion) above uses higher side local oscillator compare to RF (Radio Frequency).

Intermediate Frequency Formula or Equation

Following Intermediate Frequency formula or equations are used for this Intermediate Frequency calculator.

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