Radiating element incorporating impedance transformation capabilities

An antenna comprising:

• a dielectric member;
• an electrically conductive ground plane formed on one side of said dielectric member;
• a metal patch element formed on the other side of said dielectric member and spaced from said ground plane by said dielectric member, said patch element for radiating RF energy at a single predetermined frequency when coupled to a source of RF input energy applied to said patch;
• means for transforming the impedance of said patch element to a predetermined impedance at a feedpoint of said transforming means, said means for transforming being selectively located entirely within the perimeter of said patch element and being entirely surrounded thereby;
• and
• said means for transforming being a quarter wavelength section of metal electrically connected at one end thereof to said patch element and isolated in part at an end remote to said one end from said patch element by a slot, said feedpoint located at said remote end and said slot characterized by an absence of metal, said slot being a U-shaped slot.

An antenna comprising:

• a dielectric member;
• an electrically conductive ground plane formed on one side of said dielectric member;
• a metal patch element formed on the other side of said dielectric member and spaced from said ground plane by said dielectric member, said patch element for radiating RF energy at a single predetermined frequency when coupled to a source of RF input energy applied to said patch;
• means for transforming the impedance of said patch element to give a desired impedance at a feedpoint of said transforming means, said transforming means selectively located within the perimeter of said patch element and entirely surrounded thereby;
• said means for transforming being a section of metal electrically connected at one end to said patch element and isolated in part at its feedpoint from said patch element by a U-shaped slot, said slot characterized by an absence of metal;
• said radiating patch element being a planar rectangular patch;
• said dielectric member being a thick dielectric and having a low dielectric constant;
• said U-shaped slot being arranged with its axis of symmetry on an axis of symmetry of said patch element, such that the resonant length of said section is aligned parallel to the resonant length of said patch element;
• and
• said section defined by said U-shaped slot, being a quarter wavelength section.

A single frequency microstrip patch antenna with impedance matching capabilities comprising:

• a planar dielectric member;
• a metal patch element formed on a face of said dielectric member, said patch comprising a generally U-shaped nonconductive slot dividing said patch into a radiating element and a impedance matching transformer, said slot partially surrounding said transformer, said transformer and said radiating element being in electrical contact along the open side of said U-shaped slot;
• a feedpoint on said transformer situated at an edge opposite to the open side of said U-shaped slot;
• and
• an electrically conductive ground plane formed on the opposite face of said dielectric member.

A method of producing a single frequency microstrip patch antenna with impedance matching capabilities comprising the steps of:

• providing a planar dielectric member;
• covering said dielectric member on opposite sides with a conductive material to form a ground plane and a patch element;
• removing the conductive material of said patch element to form a U-shaped slot which divides said patch element into a radiating element and an impedance matching transformer, said slot partially surrounding said transformer, said transformer and said radiating element being in electrical contact along the open side of said U-shaped slot;
• and
• providing a feedpoint on said transformer situated at an edge opposite to said open side.