IEEE 521-2019 pdf free download

IEEE 521-2019 pdf free download.IEEE Standard Letter Designations for Radar-Frequency Bands.
1. Scope
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 are 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 ‘l2I5 M[lz-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 arc 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 arc shared by S-band radar, as distinguished from L-band radar. (‘-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
(1TU) 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 arc 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.IEEE 521-2019 pdf free download.