Compact diversity antenna with weak back near fields

An antenna for use in a radio system, wherein the radio system operates at an operating frequency, the antenna comprising:

• means forming a ground plane;
• a first antenna element extending in a loop from a first part of the ground plane to a second part of the ground plane;
• a second antenna element extending in a loop from a third part of the ground plane to a fourth part of the ground plane, the second antenna element intersecting the first antenna element at an intersection;
• feed means to feed electric signals to the first and second antenna elements at the intersection of the first and second antenna elements;
• and
• feed means being configured to supply the first and second antenna elements with currents that are essentially 180.degree. out of phase, and thereby to produce a virtual ground at the intersection of the first and second antenna elements, whereby the first and second antenna elements are electrically isolated from each other at the operating frequency.

An antenna for use in a radio system, wherein the radio system operates at an operating frequency, the antenna comprising:

• means forming a ground plane;
• a first antenna element extending in a loop from a first part of the ground plane to a second part of the ground plane;
• a second antenna element extending in a loop from a third part of the ground plane to a fourth part of the ground plane, the second antenna element intersecting the first antenna element at an intersection;
• feed means to feed electric signals to the first and second antenna elements;
• the feed means being configured to supply the first and second antenna elements with currents that are essentially 180.degree. out of phase, and thereby to produce a virtual ground at the intersection of the first and second antenna elements, whereby the first and second antenna elements are electrically isolated from each other at the operating frequency;
• and
• the ground plane forming a box, the box including a peripheral wall depending from the first and second antenna elements and a bottom spaced from the first and second antenna elements and enclosed by the peripheral wall.

A mobile phone transceiver for use in a radio system, wherein the radio system operates at an operating frequency, the mobile phone transceiver comprising:

• a housing;
• a radio transceiver disposed within the housing, the radiotransceiver including a microphone on one side of the housing;
• an antenna having means forming a ground plane with a weak near field on a first side of the antenna, and antenna elements on a second side of the antenna, the ground plane forming a ground for the antenna elements, the antenna being oriented with respect to the housing such that when the microphone is in position close to the mouth of a mobile phone user the first side of the antenna is closer to the head of the user than the second side of the antenna;
• the antenna further comprising:
• a first antenna element extending in a loop from a first part of the ground plane to a second part of the ground plane;
• a second antenna element extending in a loop from a third part of the ground plane to a fourth part of the ground plane, the second antenna element intersecting the first antenna element at an intersection;
• feed means to feed electric signals to the first and second antenna elements;
• and
• the feed means being configured to supply the first and second antenna elements with currents that are essentially 180.degree. out of phase, and thereby to produce a virtual ground at the intersection of the first and second antenna elements, whereby the first and second antenna elements are electrically isolated from each other at the operating frequency.