Abstract: It is an objective of the present invention to provide an antenna construction that allows the thickness of an antenna structure be lower than that of planar antennas according to prior art without sacrificing the radiation efficiency at the desired RF-bands as 900 MHz GSM and 1800 MHz/1900 MHz DCS/PCS. A further object of the invention is to provide an antenna construction that is insensitive to changes in positions of electrically conductive objects in the vicinity. The objectives of the invention are achieved by a loop antenna structure equipped with an electrically conductive parasitic radiator that is electro-magnetically coupled with the antenna loop. Performance at the DCS/PCS bands can be further improved by using an electrically conductive tuner element that provides a stronger electromagnetic coupling between the antenna loop and the parasitic radiator.

Abstract: An antenna module has a substrate, first and second coupling elements, and first and second resonant circuits disposed on the substrate. The first and second coupling elements are mounted to the substrate and particularly adapted to couple respective first and second frequency bands to a ground plane through respective first and second ports. The first resonant circuit has a plurality of components having electrical values selected so as to function as a band-pass filter within the first frequency band and to present a high impedance at least in the second frequency band. The second resonant circuit is coupled to the second port and has a plurality of components that have electrical values selected so as to function as a band-pass filter within the second frequency band and to present a high impedance at least in the first frequency band.

Abstract: A wireless communication device has a housing, an antenna, and a preferably flexible substrate. The housing has first and opposed second major surfaces. The antenna is fixed to the flexible substrate, and is disposed within the housing. The antenna has first and second antenna portions. The first antenna portion is disposed nearer to the first major surface than to the second, and the second antenna portion is disposed nearer to the second major surface than to the first. Preferably, the antenna radiates in two different frequency bands, and radiation in the higher band occurs entirely within the second antenna portion when the first major surface is a surface intended to mate with or lie adjacent to a user's head when the device is in use, so that the first antenna portion shields higher radiation that is received at or transmitted from the second antenna portion.

Abstract: A wireless communication device has a housing, an antenna, and a preferably flexible substrate. The housing has first and opposed second major surfaces. The antenna is fixed to the flexible substrate, and is disposed within the housing. The antenna has first and second antenna portions. The first antenna portion is disposed nearer to the first major surface than to the second, and the second antenna portion is disposed nearer to the second major surface than to the first. Preferably, the antenna radiates in two different frequency bands, and radiation in the higher band occurs entirely within the second antenna portion when the first major surface is a surface intended to mate with or lie adjacent to a user's head when the device is in use, so that the first antenna portion shields higher radiation that is received at or transmitted from the second antenna portion.