摘要:
A microelectromechanical system (MEMS) steerable electronically scanned lens array (ESA) antenna and method of frequency scanning are disclosed. The MEMS ESA antenna includes a MEMS E-plane steerable lens array and a MEMS H-plane steerable linear array. The MEMS E-plane steerable lens array includes first and second arrays of wide band radiating elements, and an array of MEMS E-plane phase shifter modules disposed between the first and second arrays of radiating elements. The MEMS H-plane steerable linear array includes a continuous transverse stub (CTS) feed array and an array of MEMS H-plane phase shifter modules at an input of the CTS feed array. The MEMS H-plane steerable linear array is disposed adjacent the first array of radiating elements of the MEMS E-plane steerable lens array for providing a planar wave front in the near field. The H-plane phase shifter modules shift RF signals input into the CTS feed array based on the phase settings of the H-plane phase shifter modules, and the E-plane phase shifter modules steer a beam radiated from the CTS feed array in an E-plane based on the phase settings of the E-plane phase shifter modules.
摘要:
Antenna structures are provided which facilitate the simultaneous radiation of multiple antenna beams. The structures include photonic manifolds that define equal-length optical paths and other optical paths whose lengths progressively change by a selected length .DELTA.L. The manifolds conduct signal pairs to radiative modules. Each signal pair includes a frequency-swept scanning signal s.sub.s and a reference signal s.sub.r whose frequency is a selected one of the sum and the difference of the frequencies of the scanning signal s.sub.s and a respective operating signal s.sub.o. Subsequently, the scanning signals are mixed with the reference signals and filtered to recover phase-shifted versions of each respective operating signal s.sub.o. The phase-shifted versions are radiated to form multiple radiated beams wherein each beam is scanned by changing the frequency of its respective scanning signal s.sub.s. The frequency of the scanning signals is selected to avoid generation of spurious radiated signals. This selection includes choosing the scanning signals so that each has a different integer number of 2.pi. phase shifts over the path length .DELTA.L. Methods of the invention permit the use of a common mixer and a common filter at each radiative module for processing all signal pairs.
摘要:
Optoelectronic switching apparatus employing optoelectronic switching devices interconnected by optical media having different delay lengths and an multiport optical coupler. The optoelectronic switching apparatus provides for a multibit true-time-delay beamsteerer for beamsteering phased array antennas. The present invention combines two types of optoelectronic devices, lasers and photodiode switches, using an interconnected passive optical network comprising the optical fibers and the optical coupler. The switches, and input and output signal networks coupled to the respective switches, are controlled using a control signal generator. Using this scheme, any input can be independently selected and a signal can be routed to any output. Furthermore, the product of the total number of different interconnect paths (N.times.M) is provided which provides a greater number of delay lengths than is provided by using only one type of switch (i.e. laser (N) or photodiode (M)) alone. The present invention also provides for improved insertion loss while increasing the number of delay paths.
摘要:
In one embodiment, a wide bandwidth, reduced depth transmit/receive antenna array includes unit cells having continuous slots, a transceiver, unbalanced feeds, impedance transformers, and exciters. The continuous slots are formed in a conductive antenna plane, and the transceiver generates and/or receives electrical signals. The unbalanced feeds may be electrically connected between the transceiver and impedance transformers which match the impedance between feed lines and the exciter. They may be located in a plane perpendicular to the direction of propagation of the radiation, and also may be arranged between the conductive antenna plane and a backplane. The exciter spans a continuous slot, and emits and/or receives radiation from the slot. The antenna array is capable of operating without a radome or balun.
摘要:
A space-fed array is selectively operable in a reflective mode or in a feed-through mode. The array includes, in an exemplary embodiment, a primary array; and a feed array. The primary array includes a first side set of radiating elements, a first set of phase shifters, a set of switches, a second set of phase shifters and a second side set of radiating elements. Each of the switches is connected between corresponding ones of the first set and the second set of phase shifters and ground, selectively settable at an open position or at a closed position. The open position corresponds to the feed through mode, and the closed position corresponds to the reflective mode.
摘要:
A multilayer switching assembly for switching high frequency signals has MEMS structures on a ceramic substrate having a top surface 500, a bottom surface and a plurality of insulating layers (510,512,514). The insulating layers are separated by at least a first conductor 502 and a second conductor 504. The first conductor 502 is connected to a ground potential. The second conductor 504 is separated from the first conductor 502 by one of the insulating layers. The second conductor presents a specific impedance (50 ohms) with respect to the first conductor to high frequency signals traveling on the second conductor.64 MEMS structures (e.g. 540,708,716,718, 720) are mounted on the top surface. Each MEMS has an input, an output, and a control. The input connected to the second conductor. The output is connected to a coplanar waveguide (508) placed on the top surface (500). The control is connected to the bottom surface.The input to each MEMS is electrically separated from the output and from the control by a third conductor (534,550,532,530) connected to the first (grounded) conductor (502). The third conductor traverses one or more of the insulating layers thereby acting as a shield and precluding the high frequency signals presented to the input from propagating to the output and to the control. The 64 MEMS are arranged in a square 8 by 8 matrix, as well as their controls. High frequency inputs and outputs to be switched by the MEMS are placed on the periphery of the substrate to further enhance the separation of signals. Terminating resistors (50 ohms) are also placed near the periphery.
摘要:
A micro electromechanical system (MEMS) transfer switch for simultaneously connecting two radio frequency (RF) input transmission lines among two RF output transmission lines. The MEMS transfer switch includes a plurality of series MEMS switching units operatively arranged with the input and output transmission lines to selectively connect a first input to a first output and a second input to a second output, or the second input to the first output and the first input to the second output.
摘要:
A reconfigurable wide band phased array antenna for generating multiple antenna beams for multiple transmit and receive functions. The antenna array comprises multiple long non-resonant TEM slot antenna apertures with RF MEMS switches disposed within the slots. The RF MEMS switches are positioned directly within the feed lines across the slots to directly control the coupling of RF energy to the slots. Multiple RF MEMS switches are used within each slot, which allows multiple transmit/receive functions and/or multiple frequencies to be supported by each slot. The frequency coverage provided by the slot antenna has a greater than 10:1 frequency range.
摘要:
A wideband end-fire array including columns or sub-arrays of flared notch radiating elements spaced along an end-fire axis and fed by a true-time-delay corporate feed network. The feed network includes a corporate feed manifold and a plurality of cables connected between a respective manifold port and a balun comprising a corresponding radiating element. The plurality of cables have corresponding electrical line lengths adapted to provide progressive time delays to signals carried between the radiating elements and the feed manifold so as to equalize the time delays due to spacing of the elements along the axis.
摘要:
A wideband electronically scanned cylindrical array includes an array of end-fire radiating elements, the elements arranged in a first plurality of columns, the columns arranged radially about a center axis of the array. A beamforming network is connected to the array of radiating elements. The beamforming network includes a power divider circuit for dividing an input RF drive signal into a second plurality of drive signals, and a matrix of electronically controlled transfer switches. A true time delay network comprising a third plurality of delay lines couples respective ones of the drive signals to the matrix of transfer switches. A third plurality of transmit amplifiers is coupled to the matrix of transfer switches, each amplifier for amplifying a respective one of the drive signals. The beamforming network further includes apparatus for coupling the amplified drive signals to selected ones of the columns of radiating elements. A beamforming controller is connected to the coupling apparatus and the matrix of transfer switches for selecting sectors of the columns of radiating elements to be driven by the drive signals to form a desired beam. The columns of radiating elements are arranged in a circularly symmetric fashion about the axis in the disclosed embodiment.