Patch antenna with embedded impedance transformer and methods for making same

• Main Authors: HOUSEL, JAMES A, CHANG, LIUNG, TSAI, MING-JU
• Format: Patent
• Language: English; French; German
• Published: 05.09.2001
• Edition: 7
• Subjects: ANTENNAS, i.e. RADIO AERIALS; BASIC ELECTRIC ELEMENTS; ELECTRICITY; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE; WAVEGUIDES

An antenna (70) is described that comprises an antenna having a patch element (72) fabricated onto a substrate (74), a ground plane (82), and an impedance transformer (80) between the patch element and the ground plane. The patch element is electrically connected to a first end of the impedance transformer, and a feed line (84) is electrically connected to a second end of the impedance transformer through the ground plane. The use of the impedance transformer allows impedance matching to be accomplished without being limited to the physical limitations of the patch element. According to a further aspect of the invention, a patch element is fabricated onto a first substrate surface and a ground plane is fabricated onto a second substrate surface, the ground plane separated from the patch element by a plurality of substrate layers. An impedance transformer is embedded between abutting substrate layers between the patch element and the ground plane, and an electrically conductive via connects a first end of the impedance transformer to a feed point on the patch element. The antenna further includes a coaxial feed having an outer conductor electrically connected to the ground plane and an inner conductor electrically connected to a second end of the impedance transformer, such that a signal is carried between the coaxial feed and the patch element through the impedance transformer.