## What are sideband frequencies?

In radio communications, a sideband is a band of frequencies higher than or lower than the carrier frequency, that are the result of the modulation process. The sidebands carry the information transmitted by the radio signal.

## What is the upper sideband frequency?

The so-called upper sidebands are those lying above the carrier. Their frequencies are: C+M C+2M C+3M C+4M C+5M …. For example, if C:M is 1:2, that is, the modulator is twice the frequency of the carrier, then the first upper sideband is: C+M = 1+2 = 3.

## What is a DSB system?

Double-sideband suppressed-carrier transmission (DSB-SC) is transmission in which frequencies produced by amplitude modulation (AM) are symmetrically spaced above and below the carrier frequency and the carrier level is reduced to the lowest practical level, ideally being completely suppressed.

## What is the difference between AM and DSBSC?

A type of DSB, called binary phase-shift keying, is used for digital telemetry. Amplitude modulation (AM) is similar to DSB but has the advantage of permitting a simpler demodulator, the envelope detector. AM is used for broadcast radio, aviation radio, citizens’ band (CB) radio, and short-wave broadcasting.

## Is 80 meters upper or lower sideband?

Lower sideband (LSB)–The common single-sideband operating mode on the 40, 80 and 160-meter amateur bands. Upper sideband (USB)–The common single-sideband operating mode on the 20, 17, 15, 12 and 10-meter HF amateur bands, and all the VHF and UHF bands.

## Is 30 meters upper or lower sideband?

You may now be asking, “Which sideband is used with SSB mode?” The convention used by hams is that bands above the 30-meter band (frequencies greater than 10 MHz), including all VHF and UHF bands, use the upper sideband (USB) – the band of frequencies adjacent to, and higher than, the carrier frequency.

## Which is higher the carrier frequency or the sideband?

In radio communications, a sideband is a band of frequencies higher than or lower than the carrier frequency, that are the result of the modulation process. The sidebands carry the information transmitted by the radio signal.

## Are there any radio astronomy frequencies shared with other services?

Unfortunately most are shared with other services : 252 GHz. Note however that Rules and Procedures from ITU specify that there is no allocation to radio astronomy in the next bands, whatever nationals regulations, so interferences can exist in these bands if they are used for that purpose : ° in Regions 1 and 3.

## How are side bands represented in a spectrogram?

Sidebands are evident in this spectrogram of an AM broadcast (The carrier is highlighted in red, the two mirrored audio spectra (green) are the lower and upper sideband). Time is represented along the vertical axis; the magnitude and frequency of the side bands changes with the program content.

## What are the different bands of radio astronomy?

Hereunder the detail of each band allocated to Radio Astronomy as defined by IAU, modified Dublin 2003 : AERONAUTICAL RADIONAVIGATION, MOBILE-SATELLITE (Earth-to-space) RADIO ASTRONOMY (°) RADIO ASTRONOMY SPACE RESEARCH (passive) Fixed Mobile except aeronautical mobile (°)