Electrically shortened Yagi having improved performance
An electrically-shortened Yagi antenna includes a boom, a first electrically-shortened end element mounted on the boom, a second electrically-shortened end element mounted on the boom; and an electrically-shortened driven element mounted on the boom and electrically shortened less than the first and second electrically-shortened end elements.
1. An electrically-shortened Yagi antenna including:
a boom;
a reflector end element electrically shortened with reference to a full sized reflector element mounted on the boom;
a director end element electrically shortened with reference to a full sized director element mounted on the boom; and
a driven element electrically shortened with reference to a full sized driven element mounted on the boom and electrically shortened in an amount less than the electrically-shortened end reflector and director elements.
2. The electrically-shortened Yagi antenna of claim 1 wherein the electrically-shortened end reflector and director elements are shortened by a first factor and the electrically-shortened driven element is shortened by a second factor less than the first factor.
3. The electrically-shortened Yagi antenna of claim 1 wherein the electrically-shortened reflector and director elements and the electrically-shortened driven element are electrically shortened using one of loading coils, linear loading via capacitive hats, and looping the elements.
4. The electrically-shortened Yagi antenna of claim 2 , further including at least one electrically-shortened passive element mounted on the boom and disposed between the driven element and the reflector element, the at least one electrically-shortened passive element shortened less than the electrically-shortened end reflector and director elements.
5. The electrically-shortened Yagi antenna of claim 4 , wherein the at least one electrically-shortened passive element is shortened by the second factor.
6. The electrically-shortened Yagi antenna of claim 4 , wherein the at least one electrically-shortened element is electrically shortened using one of loading coils, linear loading via capacitive hats, and looping the elements.
7. An electrically-shortened Yagi antenna including:
a boom;
a first passive end element electrically shortened with reference to a full sized passive element mounted on the boom at a first end thereof;
a second passive end element electrically shortened with reference to a full sized passive element mounted on the boom at a second end thereof; and
a driven element electrically shortened with reference to a full sized driven element mounted on the boom and spaced apart from the first and second passive elements, the electrically shortened driven element electrically shortened by an amount less than the first and second electrically-shortened end elements.
8. The electrically-shortened Yagi antenna of claim 7 wherein the first and second electrically-shortened passive end elements are shortened by a first factor and the electrically-shortened driven element is shortened by a second factor less than the first factor.
9. The electrically-shortened Yagi antenna of claim 7 wherein the first and second electrically-shortened passive elements and the electrically-shortened driven element are electrically shortened using one of loading coils, linear loading via capacitive hats, and looping the elements.
10. The electrically-shortened Yagi antenna of claim 8 , further including at least one electrically-shortened passive element mounted on the boom and disposed between the driven element and the first electrically-shortened passive end element, the at least one electrically-shortened passive element shortened less than the first and second electrically-shortened passive end elements.
11. The electrically-shortened Yagi antenna of claim 10 , wherein the at least one electrically-shortened passive element is shortened by the second factor.
12. The electrically-shortened Yagi antenna of claim 10 , wherein the at least one electrically-shortened passive element is electrically shortened using one of loading coils, linear loading via capacitive hats, and looping the elements.
13. The electrically-shortened Yagi antenna of claim 7 wherein:
the first electrically-shortened passive end element is a director; and
the first electrically-shortened passive end element is a reflector.
14. The electrically-shortened Yagi antenna of claim 10 wherein:
the first electrically-shortened passive end element is a first director;
the first electrically-shortened passive end element is a reflector; and
the at least one electrically-shortened passive element mounted on the boom and disposed between the driven element and the first electrically-shortened passive end element is an additional director.