RF Upconverter vs. Downconverter: Key Differences Explained

This article explains the basics of RF upconverters and downconverters, highlighting the key differences between them. These components are crucial in the RF transceiver module of a VSAT (Very Small Aperture Terminal) system.

What is an RF Upconverter?

An RF upconverter is a device that converts a low radio frequency signal to a higher radio frequency signal. The most common component used for this conversion is an RF mixer. The upconversion process can involve one or two stages of mixing.

Figure 1 (shown below) illustrates a C-band RF upconverter, which converts a 70 +/- 18 MHz signal to a frequency within the C-band (5925 to 6425 MHz).

RF upconverters are often paired with an RF Power Amplifier (PA). This combination is commonly known as a Block Up-Converter (BUC).

Figure 1: RF Upconverter and Downconverter Process

For detailed information on the design of RF upconverters, you can refer to specialized resources on the topic.

What is an RF Downconverter?

An RF downconverter, conversely, converts a high radio frequency signal to a lower radio frequency signal. Similar to RF upconverters, downconverters also employ one or two stages of mixing.

Figure 1 also shows a C-band RF downconverter, which converts a C-band frequency to a 70 +/- 18 MHz signal.

RF downconverters are frequently used in conjunction with a Low Noise Amplifier (LNA). This combined unit is called a Low Noise Block Converter (LNB).

Refer to resources on RF Transceivers for more information on modules housing both RF upconverters and downconverters.

Key Differences Between Upconverters and Downconverters