IEEE Std 521-2019 pdf download
IEEE Std 521-2019 pdf download.IEEE Standard Letter Designations for Radar-Frequency Bands.
Since World War ii, radar systems engineers have used band letter designations as a short notation for describing the frequency band of operation. This usage has continued throughout the years and is now an accepted practice of radar engineers. Radar-frequency letter designations arc used for the following reasons:
They provide a convenient method for describing the band in which the radar operates without the need for awkwardly stating the frequency limits in numerical terms. For example, it is more convenient to say an “L-band radar” than a b12l5 MHz-1400 MHz radar.” This is especially important in titles of published papers on radar, in advertising of radar systems and components, or in any other situation where a short notation is desired.
In military radar systems, the exact frequency of operation cannot usually be disclosed, but it is permissible in many cases to describe the band in which it operates. The letter designations permit this.
Each radar-frequency band has its own particular characteristics. Thus, an X-band radar will be different from an S-band radar. The letter designations are often used in this manner to indicate the particular nature of the radar, as it is influenced by its frequency. There are vast differences in characteristics, applications, and environmental constraints that distinguish radars in the different bands. It is the need to communicate concisely the whole set of characteristics that are shared by S-band radar, as distinguished from L-band radar, C-band radar, and the others, which requires the established usage of letter designations.
2. Usage
The nomenclature of Table I shall be followed when letter designations are used to describe the frequency of radar operation. When appropriate, it is suggested that the specific international Telecommunications Union (ITU) radiolocation numerical band limits be inserted parenthetically; for example, VHF (216 MHz through 225 MHz) in Region 2 or L-band (1.215 GHz through 1.4 GHz).
3. Relation to other nomenclature
The radar letter designations are consistent with the recommended nomenclature of the ITU, as shown in Table 2. Note that the high frequency (HF) and the very high frequency (VHF) definitions are identical in the two systems. The essence of the radar nomenclature is to subdivide the existing ITU bands in accordance with radar practice, without conflict or ambiguity.
NOTE 1—These international ITU frequency allocations are from the ITU Radio Regulations, 2016 Edition. The ITU defines no specific service for radar, and the frequency assignments listed are derived from those radio services that use radiolocation. The frequency allocations listed include those for both primary and secondary service. The listings of tlequency assignments are included for reference only and are subject to change. Regions 1, 2 and 3 are defined in the 2016 ITU radio regulations volume 1, articles, section 5.2 to 5.9 and can be downloaded from the website: https://www .itu.int/en!publications/ITU-R/pages/publications.aspx?parent=R-REG-RR-20 1 6&media=electronic. [B 1]
NOTE 2—The specific frequency ranges for radiolocation are listed in the NTIA (National Telecommunications and Information Administration) Manual of Regulations and Procedures for Federal Radio Frequency Management, Chapter 4 (2017 revision). The NTIA manual (known as the Redbook) can be downloaded from the website: https:H ww.ntia.doc.gov/page/20 11 /manual-regulations-and-procedures-federal-radio-frequency-rnanagement-redbook. [B3] For clarification, Region 1 in the NTIA Redbook includes ITU Regions B, C and D, while NTIA Redbook Region 2 is ITU Region A, and NTIA Redbook Region 3 is ITU region E.
NOTE 3—HF radars might operate anywhere from just above the broadcast band (1.605 Mhz) to 40 Mhz or higher. NOTE 4—Frequencies from 216 Mhz to 450 Mhz were sometimes called P-band.
NOTE 5—The official ITU designation for the ultra-high frequency band extends to 3000 MHz. In radar practice, however, the upper limit is usually taken as 1000 MHz, L-bands and S-bands being used to describe the higher UHF region.
NOTE 6—Designated for aeronautical navigation, this band is reserved (with few exceptions) exclusively for airborne radar altimeters.
NOTE 7—In the frequency band 15.4 GIIz to 15.7 GHz, stations operating in the radiolocation service cannot cause harmful interference to, or claim protection from, stations operating in the aeronautical service (WRC- 12). NOTE 8—The frequency range of 24.65 GI lz to 24.75 GHz includes satellite radiolocation (earth to space only). NOTE 9—The designation mm is derived from millimeter wave radar, and is also used to refer to V-bands,W-bands, and part ot’Ka-band.
NOTE 10—No ITU allocations are listed for frequencies above 275 GHz.
