Abstract: A system and method for detecting and locating a radio frequency emitter. A number, N, of receiving units using the same bandwidth, center frequency, and measurement time duration receive signals from the emitter. Higher Order Statistics (HOS) are used to calculate a correlation function between the received signals using one of the received signals as a reference. Results of the correlation function are used to form volumes of probabilities in a subset of an N?1 dimensional space of information regarding the location of the emitter. Each correlation function result in the subset corresponds to a single point in physical space.

Abstract: Clutter filtering of broadband radar signals is performed by obtaining a measure of the impedance of an echo target. A distance resolution is selected and then a power spectrum is calculated for the necessary transmitting signal. Further a target area profile ?(?) is estimated by utilising a correlation between the radiated signal and the received signal in form of a convolution. The target impedance is then calculated, and thereafter, the target can be filtered out using the achieved impedance characterising the echo of the target.

Abstract: Clutter filtering of broadband radar signals is performed by obtaining a measure of the impedance of an echo target. A distance resolution is selected and then a power spectrum is calculated for the necessary transmitting signal. Further a target area profile ?(?) is estimated by utilising a correlation between the radiated signal and the received signal in form of a convolution. The target impedance is then calculated, and thereafter, the target can be filtered out using the achieved impedance characterising the echo of the target.

Abstract: The present inventive concept for bistatic or monostatic radar utilization discloses a method and a system for unambiguous angle resolution of a sparse wide-band array antenna by utilizing an ultra wide-band signal, generally a wide-band noise signal which may be continuous bandwidth limited white or colored noise. The noise signal is typically generated and radiated by a transmitting antenna covering the entire reception range of a receiving sparse antenna array. An echo signal is received by the sparse receiving array containing n antenna elements, which are generally positioned with separation distances of several wavelengths without creating strong grating lobes due to the type of generated transmit signal.

Abstract: A method of modulating a microwave carrier and a modulating device are disclosed make it possible directly, onto a microwave carrier right at the operating frequency, to modulate an information signal from a digital bit-stream without the use of a conventional up-conversion chain or frequency multiplication after the modulation. A fast ferroelectric element is provided and operated with a variable voltage source controlled directly by the digital bit-stream representing the information to be modulated. The element can either be positioned between a microwave power amplifier and a radiating antenna device or even close in front of the antenna such that a collimated beam must pass through the modulation device. The element will then be able to introduce phase modulation of a passing microwave carrier.

Abstract: An antenna for simultaneous microwave transmission and reception is disclosed. The antenna comprises an array of wave-guides (10, 16) arranged side-by-side. In a typical embodiment of the array the wave-guides are rectangular wave-guides comprising a symmetrically or un-symmetrically placed ridge (8) and forming an array of vertical or horizontal columns. Opposite to the ridge at a second wall of the rectangular wave-guide slots (20, 21, 27, 28) are provided in the front wall, each aperture wave-guide being made narrow-band tuned for a respective transmitting or a receiving frequency in order to achieve a low coupling between transmitting and receiving to facilitate simultaneous transmission and reception at equal polarisation. Furthermore parallel to the array of slotted wave-guides a wave-guide filter (30, 35) may be arranged at each side forming a respective transmitting signal filter and a receiving signal filter to form a compact single aperture transmit/receive microwave antenna unit.

Abstract: A method and a system for maintaining a desired prescribed link quality from a communications terminal to a central node in a communications link system are described. A communication signal is transmitted from the communications terminal at a normal data rate on any given communication channel to the central node. The central node receiver then will order the communications terminal to step down its data rate if the central node receives poor signal quality. Then the central node will adopt its receiver channel bandwidth to the new lower data rate to obtain a desired power density per Hertz bandwidth, and simultaneously the central node will reallocate bandwidth no longer used for the particular communication terminal at the lower data rate to make this portion of its total bandwidth available for another channel in the communications link system. The method and system thereby provide an effective utilization of the available bandwidth at the system node.

Abstract: A method and a device is disclosed for the generation of a lens device including a plate of ferroelectric material, the transmission phase gradient of which is be varied over the lens by means of a controllable static electric field. The division of an aperture will depend on the number of degrees of freedom to be controlled simultaneously. According to the present invention an electromagnetically transparent highly resistive film (24, 34) is applied at both sides of a plate presenting ferroelectric properties. At two opposite edges of these resistive films highly conducting wires (22, 23 and 32, 33) are applied and electrically connected along the resistive film. The pairs of highly conductive wires at the opposite edges of each one of the two films on the plate presenting the ferroelectric properties are running perpendicular to each other.

Abstract: An antenna for simultaneous microwave transmission and reception is disclosed. The antenna comprises an array of wave-guides (10, 16) arranged side-by-side. In a typical embodiment of the array the wave-guides are rectangular wave-guides comprising a symmetrically or un-symmetrically placed ridge (8) and forming an array of vertical or horizontal columns. Opposite to the ridge at a second wall of the rectangular wave-guide slots (20, 21, 27, 28) are provided in the front wall, each aperture wave-guide being made narrow-band tuned for a respective transmitting or a receiving frequency in order to achieve a low coupling between transmitting and receiving to facilitate simultaneous transmission and reception at equal polarisation. Furthermore parallel to the array of slotted wave-guides a wave-guide filter (30, 35) may be arranged at each side forming a respective transmitting signal filter and a receiving signal filter to form a compact single aperture transmit/receive microwave antenna unit.

Abstract: A method and a device are disclosed for the generation of a surface, the reflection phase gradient of which will be varied by means of a controllable static electric field. The present solution takes into account, instead of mainly the transmissive properties, also the reflection properties of an arrangement comprising a ferroelectric material. Such a reflecting surface may contribute to an entire antenna aperture, a portion of an antenna aperture or an element in a conventional array aperture. In a general case N lobes and M nulls are to be controlled at the same time. In such a case the surface will preferably be designed as a curved surface, for instance a rotation symmetric parabola, while in other cases the reflector element may be designed just as a plane mirror. An antenna comprising such a reflector element of ferroelectric material can also form a polarization twisting Cassegrain antenna with a flat or curved main reflector element.

Abstract: A method and a device are disclosed for the generation of a surface, the reflection phase gradient or transmission phase gradient of which will be varied by means of a controllable static electric field. The present solution takes into account, instead of mainly the transmissive properties, also the reflection properties of an arrangement comprising a ferroelectric material. Such a reflecting surface may contribute to an entire antenna aperture, a portion of an antenna aperture or an element in a conventional array aperture. In a general case N lobes and M nulls are to be controlled at the same time. In such case the surface will preferably be designed as a curved surface, for instance a rotation symmetric parabola, while in other cases the reflector element may be designed just as a plane mirror. An antenna comprising such a reflector element of ferroelectric material can also form a polarization twisting Cassegrain antenna with a flat or curved main reflector element.

Abstract: A method and a device is disclosed for the generation of a lens device including a plate of ferroelectric material, the transmission phase gradient of which is be varied over the lens by means of a controllable static electric field. The lens may involve an entire antenna aperture, e.g. a feeder horn or constitute a body covering a slotted wave-guide antenna, be a portion of an antenna aperture or an element in a conventional array aperture. The division of the aperture depends on the number of degrees of freedom to be controlled simultaneously. In a general case N lobes and M nulls are to be controlled at the same time. In the most simple case with N=1 and M=0 the lens should be the entire antenna aperture. The invention is based on the fact that the direction of the wires of the control grids (1, 2) in the lens device must run perpendicular to the direction of the E-field direction of a penetrating high frequency radio wave.