Abstract: A difference drive diversity antenna structure (200) and method for a portable wireless communication device (230) aligns a first linear antenna (240) parallel to a major axis (245) of the communication device and drives dual radiators (252, 254) of a second antenna (250) at equal magnitudes but with a 180 degree phase difference. A difference drive diversity antenna structure implemented in a portable wireless communication device maintains significant decorrelation between the first antenna (240) and the second antenna (250) over the common frequency ranges of the dual radiators (252, 254). Also, antenna currents on the body of the communication device are minimized and the effects of a hand or body near the communication device are reduced.

Abstract: The multi-band slot antenna structure and method uses a single antenna to cover at least two distinct reception frequency bands using only one excitation port. In a first type of configuration, dual resonant slots (320, 325) are placed in close proximity and driven using a single differential excitation port having a positive node (370) and a negative node (375). In a second type of configuration, a half wavelength conductor (560, 660, 760) is layered over a quarter wavelength slot (520, 720) or half wavelength slot (620), and when the conductor is heavily magnetically coupled to the slot, a virtual electric short is achieved across the slot. In a third type of configuration, a quarter wavelength conductor (1060, 1160) is layered over a quarter wavelength slot (1020) or half wavelength slot (1120), and the conductor is used to capacitively or inductively load the slot (1120) at frequencies other than the natural resonant frequency of the slot (1120).

Abstract: A difference drive diversity antenna structure (200) and method for a portable wireless communication device (230) aligns a first linear antenna (240) parallel to a major axis (245) of the communication device and drives dual radiators (252, 254) of a second antenna (250) at equal magnitudes but with a 180 degree phase difference. A difference drive diversity antenna structure implemented in a portable wireless communication device maintains significant decorrelation between the first antenna (240) and the second antenna (250) over the common frequency ranges of the dual radiators (252, 254). Also, antenna currents on the body of the communication device are minimized and the effects of a hand or body near the communication device are reduced.

Abstract: A multi-layered compact slot antenna shortens the physical length of a slot antenna (710) by using more than one conductive layer, separated by a dielectric layer, to create inductor structures (790, 795) within a slot antenna. Adding inductance to a slot antenna allows a physical reduction in slot length without altering the antenna's radiant frequency range. The geometry of the inductor structures can be designed so that the electric current direction seen about the slot and the electric field direction across the slot is maintained, which aids antenna efficiency and allows arrangements of multiple compact slot antennas. Capacitor structures (780, 785) can also be included to balance out the additional stored magnetic energy in the inductor structures (790, 795).

Abstract: A balun network is provided having first and second conductor portions symmetric along a center line therebetween. A connecting conductor portion 130 couples ends of the first and second conductor portions with a spacing therebetween. The first and second conductor portions have a like-length of one-quarter wavelength. A balanced port 140 is provided between a first end of the first conductor portion 110 and a first end of the second conductor portion 120. An unbalanced port 150 is provided between a ground reference plane 160 and a first end of the first conductor portion.

Abstract: A half-wave balun network balanced for at least current is provided by a conductor section having contiguous conductor portions 130 and 140. A balanced port 110 is provided between ends of the conductor section. An unbalanced port 120 is provided between one end of the conductor section and a ground plane 107. A difference between impedances of the contiguous conductor portions 130 and 140 of the half-wave balun network provides for a selectable impedance ratio between the port impedances of the balanced and unbalanced ports 110 and 120. In one embodiment the number of different impedance conductor portions approaches infinity, thereby providing a tapered conductor section.