Multimode antenna structure

A multimode antenna structure for transmitting and receiving electromagnetic signals in a communications device, the communications device including circuitry for processing signals communicated to and from the antenna structure, the antenna structure comprising:

• a plurality of antenna ports operatively coupled to the circuitry;
• a plurality of antenna elements, each operatively coupled to a different one of the antenna ports;
• one or more connecting elements electrically connecting the antenna elements at a location on each antenna element that is spaced apart from an antenna port coupled thereto to form a single radiating structure and such that electrical currents on one antenna element flow to a connected neighboring antenna element and generally bypass the antenna port coupled to the neighboring antenna element, the electrical currents flowing through the one antenna element and the neighboring antenna element being generally equal in magnitude, such that an antenna mode excited by one antenna port is generally electrically isolated from a mode excited by another antenna port at a given desired signal frequency range and the antenna structure generates diverse antenna patterns;
• and
• an antenna pattern control mechanism operatively coupled to the plurality of antenna ports for adjusting the relative phase between signals fed to neighboring antenna ports such that a signal fed to the one antenna port has a different phase than a signal fed to the neighboring antenna port to provide antenna pattern control.

A method for controlling antenna patterns of a multimode antenna structure in a communications device transmitting and receiving electromagnetic signals, the method comprising:

• (a) providing a communications device including the antenna structure and circuitry for processing signals communicated to and from the antenna structure, said antenna structure comprising:
• a plurality of antenna ports operatively coupled to the circuitry;
• a plurality of antenna elements, each operatively coupled to a different one of the antenna ports;
• and
• one or more connecting elements electrically connecting the antenna elements at a location on each antenna element that is spaced apart from an antenna port coupled thereto to form a single radiating structure and such that electrical currents on one antenna element flow to a connected neighboring antenna element and generally bypass the antenna port coupled to the neighboring antenna element, the electrical currents flowing through the one antenna element and the neighboring antenna element being generally equal in magnitude, such that an antenna mode excited by one antenna port is generally electrically isolated from a mode excited by another antenna port at a given desired signal frequency range and the antenna structure generates diverse antenna patterns;
• and
• (b) adjusting the relative phase between signals fed to neighboring antenna ports of the antenna structure such that a signal fed to the one antenna port has a different phase than a signal fed to the neighboring antenna port to provide antenna pattern control.

A multimode antenna structure for transmitting and receiving electromagnetic signals in a communications device, the communications device including circuitry for processing signals communicated to and from the antenna structure, the antenna structure comprising:

• a plurality of antenna ports operatively coupled to the circuitry;
• a plurality of antenna elements, each operatively coupled to a different one of the antenna ports, one of said plurality of antenna elements including a slot therein defining two branch resonators;
• and
• one or more connecting elements electrically connecting the plurality of antenna elements such that electrical currents on one antenna element flow to a connected neighboring antenna element and generally bypass the antenna port coupled to the neighboring antenna element, the electrical currents flowing through the one antenna element and the neighboring antenna element being generally equal in magnitude, such that an antenna mode excited by one antenna port is generally electrically isolated from a mode excited by another antenna port at a given desired signal frequency range and the antenna structure generates diverse antenna patterns;
• and
• wherein presence of the slot in said one of the plurality of antenna elements results in a mismatch between said one of the plurality of antenna elements and another antenna element of said multimode antenna structure at the given signal frequency range to further isolate the antenna ports.