Radial-free collinear omni-directional antenna with gain and virtual ground

摘要

An omni-directional antenna operable absent ground radials and providing at least 3 dB gain at a chosen wavelength relative to a dipole includes first and second like-oriented J-pole antennas and, coupled intermediate said J-pole antennas, a quarter-wavelength non-radiating delay line. Each J-pole antenna includes a half-wave radiating element, and a quarter-wavelength non-radiating section. The quarter-wavelength non-radiating delay line together with the quarter-wavelength non-radiation section of the second J-pole provide a half-wave non-radiating delay line. The result is that RF energy radiated by the first and second half-wave radiating elements are in proper phase, whereby gain is achieved. RF energy is coupled to the first J-pole antenna a distance Δ above the zero impedance end of that antenna.

主权项

1. An omni-directional antenna operable absent ground radials and providing at least 2 dB gain at a chosen wavelength relative to a dipole, comprising:
a first J-pole antenna that includes a half-wavelength radiating element, a quarter-wavelength matching section, and has a low impedance first end and a high impedance second end, and has an RF feedpoint impedance a distance Δ above said low impedance first end; a second J-pole antenna that includes a half-wavelength radiating element, a quarter-wavelength non-radiating delay line section, and has a low impedance first end and a high impedance second end; a quarter-wavelength non-radiating delay line disposed intermediate said first J-pole antenna and said second J-pole antenna, and having a low impedance first end that is electrically connected to said low impedance first end of said second J-pole antenna, and having a high impedance second end that is electrically connected to said high impedance second end of said first J-pole antenna; wherein collectively said quarter-wavelength non-radiating delay line section of said second J-pole antenna and said quarter-wavelength non-radiating delay line form a half-wavelength non-radiating delay line; where RF energy radiated by said half-wavelength radiating element of said first J-pole antenna and radiated by said half-wavelength radiating element of said second J-pole antenna are in proper phase; wherein at least 2 dB gain relative to a dipole antenna is achieved.