摘要:
The invention relates to antenna elements for the UHF and VHF range for antennas of an airborne vehicle with empennage parts. These antenna elements are integrated into the empennage parts (L) which are made of a dielectric material and are configured in such a way that they radiate directionally broadband in flight direction. The empennage parts are made, for example, of ceramic, and the antenna elements are embedded therein or are applied to their surface. The antenna elements (A) are preferably expanding Vivaldi-type slot radiators that are halved along their axis of symmetry and use the airborne vehicle (F) as an electrical mirror. Arranging the antenna elements in the area of the rudder maximizes both the aperture and the distance between the phase centers of the individual elements, but no additional volume is required for the antennas.
摘要:
An aircraft phased array antenna system has transmit and receive antenna structures externally mounted on the aircraft fuselage. Each antenna comprises a plurality of phased array elements and antenna power and support equipment. Aerodynamically shaping antenna structure to enclose an antenna element grid provides additional antenna structure volume, which is efficiently utilized by locating antenna support equipment within the antenna structure. To control signal attenuation a receive antenna internal converter converts receive frequency signals to L-band frequency signals for aircraft use, and a similar transmit antenna converter converts L-band frequency signals to transmit frequency signals, thus unconstraining antenna to internal aircraft equipment spacing. To reduce power loss and cabling weight, antenna operating power is first generated in the 28 to 270 volts DC range within the aircraft, and locally converted in each antenna to the 3 to 6 volt DC power to operate each antenna's phased array elements.
摘要:
A polyhedral-shaped inflatable structure having substantially continuous inner and outer flexible surfaces is inflatable with air or gas so that a radar reflector, comprising a plurality of conterminous corner reflectors, is thereby positioned within the inflatable structure to reflect radar waves. The corner reflectors are preferably made of metallized reflective plastic film attached to a plurality of support filaments. Support members attached to the support filaments are pivotally disposed adjacent to the inner flexible surface to position the radar reflector within the inflatable structure. Removable fasteners are disposed adjacent to the outer flexible surface and concentrically proximate to the support members to thereby fasten the radar reflector to the inflatable structure without puncturing the inner and outer flexible surfaces. The radar reflector may be manually repositioned while the inflatable structure is inflated by removing the fasteners, repositioning the radar reflector, and refastening the fasteners concentrically proximate to the support members.
摘要:
A microwave reflector antenna for use on an aircraft. The microwave reflector antenna has a stationary plate that is attached to and stationary relative to the aircraft. A rotary plate rotates relative to the stationary plate about an azimuth axis. A rotary joint is attached to the rotary plate and has an axis of rotation that is aligned with the azimuth axis. A reflector is attached to the rotary plate adjacent the rotary joint so that the azimuth axis does not intersect the reflector. Individual ball bearings are positioned between the rotary plate and the stationary plate to allow the rotary plate to rotate about the azimuth axis. The stationary plate has gear teeth positioned along a peripheral side wall of the stationary plate. An azimuth motor is attached to the rotary plate and engaged with the gear teeth to selectively rotate the rotary plate about the azimuth axis.
摘要:
A reflector for use under a radome disposed on a mobile platform such as an aircraft for reflecting a portion of the electromagnetic energy radiated by an antenna disposed under the radome such that the reflected portion of energy impinges the radome at an angle normal thereto, thereby reducing or eliminating further reflections of the reflected portion of energy within the radome toward the mobile platform on which the radome is mounted. In one preferred embodiment the radome includes a base portion which is covered with a cover of radar absorbing material (RAM). In another embodiment the radome includes a curved base portion which is adapted to match the curvature of the surface of the mobile platform on which the reflector is mounted.
摘要:
A folded microstrip antenna for a flight aggregate or aircraft can be arranged around edges of thin structural parts, such as wings, tail units or control flaps, such that its surface is identical with the structure and folding takes place at the edge of the structure. The antenna is constructed such that its characteristic impedance is much higher at the folding edge than at ends of the structural antenna away from the edge. As a result, an approximately omnidirectional characteristic can be achieved.
摘要:
A testing apparatus for testing mobile telephones includes an antenna coupler, a holder and a testing device. The antenna coupler includes a printed circuit board upon one side of which is formed a slot antenna operative in a first frequency range and a dipole antenna operative in a second frequency range. The holder secures a mobile telephone under test in proximity to the antenna coupler. A coupler formed on a second side of the printed circuit board selectively supplies signals received by one of the antenna elements to the testing device. The testing device measures transmission and reception characteristics of the mobile telephone under test, including transmission phase error, frequency error, power and spectrum, and bit error rate.
摘要:
A system for calibrating airborne direction finding antenna arrays eliminates the problem of trying to maintain a constant depression angle when flying an airplane directly over a calibration antenna to collect deep depression angle data. The deep depression angle data necessary for calibration is provided by data from a scale model of the aircraft having a direction-finding array which simulates the actual direction-finding array on the aircraft. In order to collect deep depression angle data, the model is pivoted through 360null while maintaining a controlled depression angle. Thus, it is unnecessary for calibration to actually fly a plane to attempt to obtain deep depression angle measurements. In the subject system, only a single depression set of data is required from the aircraft. Thus, with the exception of baseline shallow depression angle data from this plane, the calibration data comes strictly from the scale model, which is much more easily obtained. Optimization techniques are used in which a set of data is collected from the airplane at one shallow depression angle which is used with the data collected from the scale model at the same shallow depression angle to derive a complex set of optimized weights that are then applied to the data collected from the model at the remainder of the depression angles to obtain the appropriate database for use on this aircraft for direction finding. In so doing, the aircraft need only be flown to establish data at a relatively shallow depression angle which can be easily collected by an aircraft flying in circles or banana pattern at some distance from the calibration antenna.
摘要:
A switching circuit for use at the antenna of a multiband mobile cellular handset comprises an antenna port 10, a TX low band port 14, a TX high band port 12 and at least one RX port 16. A single pole, triple throw solid state voltage-controlled switch made up of four PIN diodes D1 to D4 selectively connects any one of the TX low band port, TX high band port and RX port to the antenna port. No diplexer is used to separate the low and high band parts o the circuit.
摘要:
A millimeter wave beacon includes a millimeter wave transmitter that produces at least one signal and plurality of antennas, coupled to the millimeter wave transmitter, that each emit millimeter wave radiation in response to the at least one signal. In one embodiment, the antennas are constructed and oriented to produce an overlapping signal field in which millimeter wave radiation emitted from multiple of the antennas can be detected. The millimeter wave radiation can be pulsed to encode various information of interest. Determination of the direction of approach to the beacon is facilitated by multiple antennas transmitting signals having different pulse encodings and/or different frequencies.