Abstract: A method of routing a frequency hopping signal to one of two transmitting antennas in a multiple carrier communication system is disclosed. The method comprises storing known a-priori information regarding frequency hopping signal assignments, scanning a transmitter frequency and antenna path assignment table to determine the closest existing transmitting frequency and its antenna to the frequency hopping signal to be assigned, assigning the frequency hopping signal to an available path on the other antenna, and updating the transmitter frequency and antenna path assignment table. In addition the method includes determining whether the assigned path on the other antenna conflicts with existing frequency assignments, and preempting the antenna assignment when a conflict exists.

Abstract: A phased array antenna (12) that includes a plurality of multiple spiral arm antenna elements (10). The antenna elements (10) are hexagonal in shape and are aligned in a triangular lattice geometry, where the elements (10) are arranged in rings around a common center element (32). The elements (10) include at least two arms (18, 20) which terminate at opposite sides of the element (10). The ends (26, 28) of the arms (18, 20) of diagonally adjacent elements (10) are positioned proximate to each other to provide inter-element coupling to increase the bandwidth of the antenna (12). The tight coupling of the antenna elements (10) also reduces the RCS of the antenna (12).

Abstract: A wide band, single aperture antenna system (70) that provides simultaneous detection of both RHCP and LHCP signals. The antenna system (70) includes a multiple arm spiral antenna (10) that has spiral arm elements (12, 14, 16, 18) with no sharp transitions. To simultaneously both RHCP and LHCP sensitivity, an antenna feed is connected to both the center end and the outer end of each of the antenna arm elements (12, 14, 16, 18). A separate N-port transformer (74, 78) is connected to both the end feed and the center feed for all of the arms (12, 14, 16, 18) to provide impedance matching and cross-polarization compensation. An NXN port modeformer (76, 80) is connected to the N-port transformers (74, 78) to separate the various modes. The modeformers (76,80) separate the LHCP and RHCP modes to provide an accurate AoA estimation.

Abstract: An aircraft antenna system integrated into one or more walls of an equipment pod (12) mounted beneath an aircraft (10). The equipment pod (12) has at least one wall with an antenna notch built into it. The antenna notch is tapered or flared toward a wider opening and is bounded on each side by conductive portions of the same pod wall. Other walls of the pod (12) are made from conductive materials, which are in electrical contact with the aircraft structure. The equipment pod (12) provide multiple antenna structures for use in a variety of aircraft applications. Further, use of multiple pods (12) allows an aircraft to be more easily reconfigured for different missions by removing and replacing the equipment pod.

Abstract: The present invention provides a modeforming circuit (100). The modeforming circuit (100) includes a first matrix circuit (102) comprising an interconnected network of transmission lines (208-212) and phase shifters (216-218) that implement at least one N/2.times.N/2 identity matrix and at least one N/2.times.N/2 phase shift matrix. The first matrix circuit (102) is connected in series to a second matrix circuit (104). The second matrix circuit (104) includes an interconnected network of phase shifters that implements at least one N/2.times.N/2 phase shift matrix. The modeforming circuit (100) may further include a third matrix circuit (106) connected in series with the second matrix circuit (104). The third matrix circuit (106) includes a network of transmission lines (220-230) that reorder N inputs to N mode outputs. The first matrix circuit (102) may be implemented as a first matrix sub-circuit (108) connected in series with a second matrix sub-circuit (110) to provide even further reduced complexity.

Abstract: An implementation of a Butler matrix transformation used to process antenna signals and, in particular, to transform signals obtained from an N-port antenna into mode signals used for direction finding and other purposes. A reverse transformation is used when the antenna is operating in a transmit mode. Instead of using a single Nth order transformation matrix, the circuit of the invention employs a decomposed form of the transformation matrix, thereby reducing the complexity of the transformation by using lower-order matrices. In an example of the invention for an 8.times.8 transformation, the circuit complexity is further reduced by using an additional level of decomposition, in which phase shifting is effected by a circuit implementation of a single 8.times.8 diagonal phase shift matrix requiring only three phase shift circuits. Reduction in circuit complexity, particularly in the number of phase shift circuits, reduces bias errors in the overall transformation and reduces fabrication cost.

Abstract: A solderless right-angle interconnect is provided for achieving flexible, low-profile and enhanced performance high frequency signal interconnections. The interconnect includes a compressible conductive pin assembly which has a first end electrically coupled to a first transmission path and a second end electrically coupled to a stripline circuit trace which provides a second transmission path. According to one embodiment, a springy compressible conductive button is located in a recessed chamber at the second end of the conductive pin and partially extends from the end thereof. According to another embodiment, a springy conductive bellows is formed intermediate the first and second ends of the pin assembly. The second end of the conductive pin further includes at least one tapered edge. A conductive ground layer is further provided for substantially enclosing the interconnect and providing a ground reference thereabout.

Abstract: A low-profile multioctave frequency band microwave mode forming network is provided which includes a plurality of circuit layers having circuitry for receiving M feed signals which may provide M beams or modes of operation. Each circuit layer has a dielectric board with circuitry formed on top and bottom surfaces thereof and is sandwiched between top and bottom dielectric layers to form a tri-plate stripline circuitry. The circuit layers are dielectrically isolated from one another and further separated by conductive ground planes. The circuitry includes a plurality of couplers, phase shifters and transmissions lines which do not require transmission line cross-overs on any given surface. A plurality of right-angle RF interconnects are included for providing electrical connection to the circuitry. Output ports are provided for coupling said feed network to N elements of an antenna system.

Abstract: A solderless right-angle interconnect is provided for achieving flexible, low-profile and enhanced performance high frequency signal interconnections. The interconnect includes a conductive pin which has a first end electrically coupled to a first transmission path and a second end electrically coupled to a stripline circuit trace which provides a second transmission path. A springy compressible conductive button is located in a recessed chamber at the second end of the conductive pin and partially extends from the end thereof. The second end of the conductive pin further includes at least one tapered edge. A conductive ground layer is further provided for substantially enclosing the interconnect and providing a ground reference thereabout. In a first embodiment, the conductor forming the first transmission path includes a coaxial cable coupled to the conductive pin.