Abstract: The utilization of small antennas for mobile devices and for low frequency (long wavelength) applications is desired. Further, efficient use of transmission power is desirable, especially in mobile applications. For this purpose, a system is provided that includes one or more of: a multiple-resonator transmitter/receiver, a high bandwidth electrically small antenna, a resonator with a variable feed location, a resonator with a variable reactive component load, and a method for estimating a resonator system response to a component configuration and selected excitation.

Abstract: The utilization of small antennas for mobile devices and for low frequency (long wavelength) applications is desired. Further, efficient use of transmission power is desirable, especially in mobile applications. For this purpose, a system is provided that includes one or more of: a multiple-resonator transmitter/receiver, a high bandwidth electrically small antenna, a resonator with a variable feed location, a resonator with a variable reactive component load, and a method for estimating a resonator system response to a component configuration and selected excitation.

Abstract: An improved tuning method is used in conjunction with a set of nested electrically conducting cones to increase the frequency band over which the resulting radiating system functions as an electrically small antenna with controlled variation in input impedance. This technique enables switching of the frequency band by means of simple circuits that can be activated by a control voltage.

Abstract: An improved tuning method is used in conjunction with a set of nested electrically conducting cones to increase the frequency band over which the resulting radiating system functions as an electrically small antenna with controlled variation in input impedance. This technique enables switching of the frequency band by means of simple circuits that can be activated by a control voltage.

Abstract: An improved tuning method is used in conjunction with a set of nested electrically conducting cones to increase the frequency band over which the resulting radiating system functions as an electrically small antenna with controlled variation in input impedance. This technique enables switching of the frequency band by means of simple circuits that can be activated by a control voltage.

Abstract: A planar antenna is described which employs a thin patch of conductive material supported above and substantially parallel to a closely spaced thin conductive ground surface. Two or more narrow slots are positioned in the ground surface beneath the conductive patch. A microstrip transmission line, placed below the ground surface, excites the slots in series. The length of the microstrip line between the slots, the position of the microstrip line across the slots, and the dimensions of the slots are chosen to excite two orthogonal modes in the conductive patch in phase quadrature. This excitation results in a planar antenna which receives and transmits electromagnetic waves of circular polarization. The antenna may also employ a coplanar waveguide transmission line instead of the aformentioned microstrip transmission line. The coupling apertures then form slot discontinuities in series with the coplanar transmission line, which are positioned under the conductive patch.

Abstract: A planar antenna is described which comprises a sandwich like structure of a radiating patch, ground plane and transmission feed line. Capacitive means connect the path to the feed line through a rectangular aperture in the ground plane. The energization of the feed line excites radiating modes in both the aperture and the space between the radiating patch and ground plane thereby resulting in an improved impedance bandwidth.

Abstract: A thin planar curved microstrip antenna is described which exhibits substantially constant input impedance characteristics over a wide frequency band. The impedance characteristic is achieved by shaping the ground surface such that the ratio of the width of the radiating element to its distance from the ground surface stays constant for a given curvature.

Abstract: A planar antenna is described which employs a pair of closely spaced parallel ground planes and a radiating element which is a composite aperture (hybrid slot) formed into the upper ground plane. One portion of the radiating element is a long narrow slot which may have the shape of a rectangle of high aspect ratio. The other portion is an annular slot which may be circular in shape. Electromagnetic energy is conveyed to and from the slots in the upper ground plane by means of a feed conductor parallel to and sandwiched between the two ground planes. The maximum of the resulting field pattern is in the plane of the antenna and the pattern may be either directional or omnidirectional in that plane. When used as a receiving antenna, this antenna responds to both the electric and magnetic fields.