Rhombic antenna: Difference between revisions

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File:Antenna boom comparison.png

Rhombic antenna signal-gathering action compared to other end-fire, backfire and traveling-wave types.

A rhombic antenna is a broadband directional antenna, mostly commonly used in HF (high frequency, also called shortwave) ranges.

It is named after its "rhombic" diamond shape, with each side typically at least onewavelength or longer in length. Each vertex is supported by a pole, typically at least one wavelength tall. It is fed at one of the sharp angles through a balun transformer, and is terminated at the opposite sharp angle with a non-inductive resistor. It is directional towards the resistor end, so it points towards the region of the world it is designed to serve.

The rhombic antenna can radiate at elevation angles close to the horizon or at higher angles depending on its height above ground relative to the operating frequency. Likewise, its beam can be narrow or broad, depending primarily on its length. A proper combination of size, height, and operating frequency make it fit for medium or long range communication.

Due to its considerable size, it is not very practical as the sole antenna of a radio station if geographic coverage requirements are expected to change rapidly. Moreover, it plainly requires a lot of land—especially if several must be combined to serve a variety of geographic regions at different distances and on widely different frequencies.

On the other hand, it is one of the best options for sustained long distance communications over point-to-point circuits. Its size gives it substantial gain, and allows it to capture energy from a wide area, thus making it a little less susceptible to sharply localized fading than smaller antennas.

Advantages of Rhombic Antennas

Its input impedence & radiation pattern are relatively constant over a 2:1 range of frequencies.
Multiple rhombic antennas can be connected in an end-to-end fashion to form MUSA (Multiple Unit Steerable Antenna). MUSA arrays can receive long distance, short wave, horizontally polarized down coming waves.

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 [[Image:Antenna_boom_comparison.png|frame|Rhombic antenna signal-gathering action compared to other end-fire, backfire and traveling-wave types.]]
 A '''rhombic antenna''' is a [[broadband]] directional [[antenna (electronics)|antenna]], mostly used in HF (high frequency, also called [[shortwave]]) ranges.
-It is named after its "[[rhombus|rhombic]]" diamond shape, with each side typically being of [[wavelength]] size.  Each [[vertex]] is supported by a pole, several metres tall.  It is fed at one of the sharp angles through a [[balun]] [[transformer]], and is terminated at the opposite sharp angle with a non-[[inductance|inductive]] [[resistor]].  It is directional towards the resistor end, so it points towards the region of the world it is designed to serve.
+It is named after its "[[rhombus|rhombic]]" diamond shape, with each side typically   [[wavelength]] .  Each [[vertex]] is supported by a pole,   tall.  It is fed at one of the sharp angles through a [[balun]] [[transformer]], and is terminated at the opposite sharp angle with a non-[[inductance|inductive]] [[resistor]].  It is directional towards the resistor end, so it points towards the region of the world it is designed to serve.
-The rhombic antenna can radiate close to the horizon or at a higher angle depending on its length, width, and height relative to the operating frequency.  Likewise, its beam can be narrow or broad.  A proper combination of size, height, and operating frequency make it fit for short- medium- or long-range communication.
+The rhombic antenna can radiate close to the horizon or at higher  depending on its    relative to the operating frequency.  Likewise, its beam can be narrow or broad.  A proper combination of size, height, and operating frequency make it fit for medium or longrange communication.
-Due to its considerable size, it is not very practical as the sole antenna of a [[radio station]] if operating conditions are expected to change rapidly.  Moreover, it plainly requires a lot of land&mdash;especially if several must be combined to serve a variety of geographic targets at different distance ranges and on widely different frequencies.
+Due to its considerable size, it is not very practical as the sole antenna of a [[radio station]] if   are expected to change rapidly.  Moreover, it plainly requires a lot of land&mdash;especially if several must be combined to serve a variety of geographic  at different  and on widely different frequencies.
-On the other hand, it is one of the best options for predictable point-to-point circuits.  Its size gives it a degree of [[gain]], and allows it to capture energy from a wide area, thus making it a little less susceptible to sharply localized [[fading]] than smaller antennas.
+On the other hand, it is one of the best options for  point-to-point circuits.  Its size gives it  [[gain]], and allows it to capture energy from a wide area, thus making it a little less susceptible to sharply localized [[fading]] than smaller antennas.
-==Advantages of rhombic antennas ==
+==Advantages of   ==
+* Its input impedence & radiation pattern        of .
-* By connecting rhombic antenna in END-END passion we can design MUSA (Multiple Unit Steerable Antenna) by using MUSA we can receive long distance, short wave, Horizontally polarized down coming waves.
+*  rhombic  in -    MUSA (Multiple Unit Steerable Antenna) MUSA  can receive long distance, short wave,  polarized down coming waves.
-* Its input impedence & radiation pattern input do not change ever consider variable of frequency.
-* It is highly efficient & widely used antenna in radio communication
-* These are also used for long distance F-Layer propagation
 [[Category:radio ]]