Abstract: An antenna is provided which includes a primary folded dipole element and a feed for the primary folded dipole element. The primary folded dipole element is operable to resonate at a first frequency range. A parasitic dipole element is located within the primary folded dipole element and is spaced therefrom. The parasitic dipole element is operable to resonate at a frequency range that is higher than the first frequency range. Additional parasitic dipole elements may be located within the primary folded dipole element and spaced therefrom to resonate at different frequency ranges.

Abstract: A license plate frame assembly comprises a license plate frame, a seat member attached to the license plate frame, and a first antenna carried at the seat member in a position facing at an angle from the vertical. Also, multiple antennas may be carried by the license plate frame.

Abstract: An omnidirectional, multiple unit antenna comprises a mounting assembly and a plurality of sector antennas carried on the mounting assembly. Each sector antenna is active to send or receive signals primarily through an angular, horizontal sector having an angle of no more than about 180° around the mounting assembly. The sector antennas carried on the mounting assembly are positioned so that sectors of the respective antennas cover substantially all horizontal directions. Each sector antenna preferably has a separate input, for improved control.

Abstract: A carrier rejection circuit for improving carrier rejection in a balanced modulator includes balun transformers, connected to the carrier signal port and the modulated signal port, which reduces parasitic carrier leakage by reducing the average voltages at the ports, offset adjustment circuitry, connected to the modulating signal port, which applies an adjustable offset voltage to the modulating signal to reduce in-phase parasitic carrier leakage and carrier leakage caused by offset voltage at the modulating port, and a reactance network, connected between the carrier signal port and the modulated signal port, for reducing quadrature-phase parasitic carrier leakage.

Abstract: A communication system for transmitting data between a transmitting platform and a receiving platform moving relative to each other. A phased array antenna forms the transmitting antenna rotated on the transmitting platform and a single dipole, oriented parallel to the transmitting antenna, forms the receive antenna located on the receiving platform. The phased array antenna is split into small sections, each section comprising dipole elements and a matching network, including a feedpoint. The receive antenna is mounted close to the transmitting antenna.

Abstract: An MRI signal processing apparatus is disclosed which provides a low noise output signal for use in a multi-coil MRI system, wherein each sensing coil provides an input signal to the MRI signal processing apparatus.

Abstract: A communication system for transmitting data between a transmitting platform and a receiving platform, having two equal lengths of leaky coaxial cable forming the transmitting antenna which is located on the transmitting platform and the receive antenna is located on the receiving platform. The two equal lengths of leaky coaxial cable form a circle wherein one end of each of the equal lengths is a feedpoint for inputting data and the other end of each of the two equal lengths is terminated with a resistor to ground. The receive antenna is maintained a predetermined distance from the plane of the transmitting antenna.