Dual ground plane microstrip antennas
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorCyril M. Kaloi
Life of this patent
Estimating the term…
Abstract
Microstrip antenna systems having two ground planes spaced apart by a dietric substrate and radiating elements coplanar with one of the two ground planes, or sandwiched within the dielectric substrate separating the two ground planes adjacent a window in one of the ground planes. The two ground planes are shorted together in most instances, and the dual ground plane system provides a reduction in the leakage losses of tranmission lines feeding and/or interconnecting the microstrip antenna radiating elements. The dual ground plane system also provides a reduction in coupling between arrayed radiation elements as well as an increase in bandwidth, in some instances.
Claims33
A dual ground plane strip-line fed electric microstrip antenna having low physical profile and conformal arraying capability, comprising:
- a. a pair of thin conducting parallel ground planes;
- b. a dielectric substrate separating and spacing apart said ground planes one from the other to provide an upper and a lower ground plane;
- said upper ground plane having a portion of predetermined dimensions of the area thereof removed;
- c. a thin electrically conducting radiating element having a feedpoint thereon being formed coplanar with said upper ground plane within said removed area thereof, and being electrically separated from said coplanar upper ground plane and from said lower ground plane;
- d. a stripline transmission line being located within said dielectric substrate between said upper and lower ground planes;
- said stripline transmission line being positioned within and surrounded on all surfaces by said dielectric substrate, and being non-copolanar with and electrically separated from said upper and lower ground planes;
- said stripline transmission line having one end thereof extending within said dielectric substrate to a point beneath said radiating element feedpoint;
- e. means for electrically connecting said one end of the stripline transmission line to said radiating element feedpoint;
- f. said upper and lower ground planes being shorted together by a plurality of electrically conductive shorting means;
- the strategic positioning of said shorting means on said upper ground plane and the location and dimensions of the area of said upper ground plane being operable to eliminate induced current and charge oscillation modes from occurring in said upper ground plane and prevent undesirable radiation from the upper ground plane including undesirable cross-polarization radiation;
- g. said dual ground planes adjacent the area of said stripline transmission line operating to cause a reduction in transmission line leakage losses from said stripline transmission line without adversely affecting the operation of said radiating element, and said shorted upper ground plane operating to reduce coupling between closely spaced microstrip radiation elements.
A dual ground plane stripline-fed magnetic microstrip antenna having low physical profile and conformal arraying capability, comprising:
- a. a pair of thin conducting parallel ground planes;
- b. a dielectric substrate separating and spacing apart said ground planes one from the other to provide an upper and a lower ground plane;
- said upper ground plane having a portion of predetermined dimensions of the area thereof removed;
- c. a thin electrically conducting radiating element having a feedpoint thereon being formed coplanar with said upper ground plane within said removed area thereof;
- said radiating element having one edge thereof shorted to at least one of said ground planes by at least one radiating element shorting means;
- d. a stripline transmission line being located within said dielectric substrate between said upper and lower ground planes;
- said stripline transmission line being positioned within and surrounded on all surfaces by said dielectric substrate, and being non-coplanar with and electrically separated from said upper and lower ground planes;
- said stripline transmission line having one end thereof extending within said dielectric substrate to a point beneath said radiating element feedpoint;
- e. means for electrically connecting said one end of the stripline transmission line to said radiating element feedpoint;
- f. said upper and lower ground planes being shorted together by a plurality of electrically conductive shorting means;
- the strategic positioning of said shorting means on said upper ground plane and the location and dimensions of the area of said upper ground plane being operable to eliminate induced current and charge oscillation modes from occurring in said upper ground plane and prevent undesirable radiation from the upper ground plane including undesirable cross-polarization radiation;
- g. said dual ground planes adjacent the area of said stripline transmission line operating to cause a reduction in transmission line leakage losses from said stripline transmission line without adversely affecting the operation of said radiating element, and said shorted upper ground plane operating to reduce coupling between closely spaced microstrip radiation elements.
Dependencies are inferred from the claim text.