Abstract: An electroporation system including one or more of a pipette, a pipette tip, a pipette docking assembly, and a pulse generator. The pipette docking assembly includes a pipette station, a pipette station guard, and a reservoir (e.g., a buffer tube). A method for transfecting a cell with a payload including providing an electroporation system, providing the cell, providing the payload, introducing the cell and the payload into a pipette tip, and electroporating the cell within the pipette tip by operating the electroporation system.

Abstract: A unit element of a periodically loaded edge slot array includes a reduced-height waveguide section having top and bottom walls and opposed first and second sidewalls defining a waveguide space. A slot is formed in the first side wall at an angle with respect to a waveguide longitudinal axis. At least one conductive post protrudes from the top wall into the waveguide space. The unit element can be incorporated into sticks of an electronically scanned antenna.

Abstract: An integrated module for an active antenna assembly is disclosed. The integrated module is switchable between a receive mode and a transmit mode and includes active components and a dual input wideband balun. The active components includes amplifiers and micro electro-mechanical system (MEMS) switches. The integrated module is adapted for positioning directly behind a radiator of an antenna array.

Abstract: A unit element of a periodically loaded edge slot array includes a reduced-height waveguide section having top and bottom walls and opposed first and second sidewalls defining a waveguide space. A slot is formed in the first side wall at an angle with respect to a waveguide longitudinal axis. At least one conductive post protrudes from the top wall into the waveguide space. The unit element can be incorporated into sticks of an electronically scanned antenna.

Abstract: A planar, low-profile, very wide frequency bandwidth, wide-scan, dual-linear or circular-polarized phased array antenna using integrated stacked-disc radiator tiles. The stacked-disc radiator configuration comprises a lower active radiator fed by a pair of probes for each polarization state, and a parasitic radiator separated from the active radiator by dielectric material. The stacked-disc radiator is integrated with its multi-layer feed circuits in a very compact package. The feed circuits include 90.degree. hybrid coupler circuits and 180.degree. hybrid coupler circuits that couple dual linear or dual circular polarized energy to and from the disk radiators.

Abstract: A very wide-band or dual-band phased array antenna using stacked-disc radiators on stacked-dielectric cylindrical posts to form radiator elements. Each radiator element includes a ground plane, a lower dielectric cylindrical post of a high dielectric material adjacent the ground plane, a lower thin conductive radiator disc formed on the upper surface of the lower dielectric post, an upper dielectric cylindrical post of a low dielectric material disposed on top of the lower post and lower radiator disc, and an upper thin radiator disc or annular ring formed on the upper surface of the upper post. The first radiator disc is excited by two pairs of probes arranged in orthogonal locations. Each pair of probes can be fed by coaxial cables with 180 degree phase reversal. The second radiator disc or annular ring is a parasitic radiator without feeding probes. Depending on the feed arrangement, the radiator elements can achieve single-linear polarization, dual-linear polarization or circular polarization.

Abstract: A multiband phased-array antenna interleaves tapered-element radiators with waveguide radiator to facilitate the simultaneous radiation of antenna beams across a bandwidth in excess of two octaves. The launch ends of the waveguide radiators collectively define a ground plane. The tapered-element radiators have pairs of tapered wings which are extended past the ground plane by a distance which is selected to establish a predetermined tapered wing radiation impedance. The radiators of each type are spaced apart by a span which insures that they will not generate grating lobes at the highest frequency which they respectively radiate.

Abstract: A multiple layer dipole array that provides for a multi-frequency band phased array antenna. Several layers of dipole pair arrays, each tuned to a different frequency band, are stacked relative to each other along the transmission/reception direction. The highest frequency array is in front of the next lowest frequency array and so forth. Due to the frequency selective property of the arrays, incident high frequency signals are completely absorbed by the highest frequency array. In regard to incident low frequency signals, the insertion loss due to higher frequency arrays is small resulting in good performance of the lower frequency arrays. The multi-frequency band phased array antenna may use active or driven dipole pairs, or parasitic elements that form the multiple layer dipoles. The multiple layer dipole array of the present invention may employ corporate feed circuit boards and a corporate feed power divider, using strip transmission line circuits, for example.

Abstract: An ultra wideband (UWB) phased array antenna using a frequency-multiplexing, space-fed lens with a UWB feed horn achieves multi-octave bandwidth. The lens includes two UWB radiating apertures with relatively narrow band phase shifters connecting corresponding radiating elements of the arrays. Each aperture multiplexes the incoming UWB signal into separate frequency bands so that the phase shifters need only be tuned to these narrower frequency bands, and are set to form a beam in the desired direction. For wide instantaneous bandwidth operation, the beams from the various frequency bands are collimated in the same direction. For multi-mode operation, the beams corresponding to the various frequency bands are formed in different directions. The phase shifters need have a maximum phase shift of 360 degrees.

Abstract: An apparatus for testing a microwave phased array antenna having a plurality of radiating elements includes a transmission line for signal injection and switching components to selectively establish signal paths from a transmitter, and through a plurality of transmit/receive modules, to a performance monitor. In accordance with the present invention the switching components can be set to establish a receive signal path through the apparatus to test the receive mode of the individual modules. Alternatively, the switching components can be set to establish a transmit signal path through the apparatus to test the transmit mode of the individual modules. Further, the switching components can be set to selectively establish a receive signal path or a transmit signal path through either isolated individual modules or through all modules simultaneously.

Abstract: An apparatus and a method for enhancing the radar cross section of a target. The present invention is an impulse radar system that implements a method that comprises the following steps. A pilot impulse radar pulse is transmitted at a target. The pilot pulse comprises a plurality of individual pulses having respective distinct frequencies generated by the impulse radar system. A return pulse from the target is received by the impulse radar system and provides information indicative of target scattering centers. The return pulse is used as a calibration signal for generating a phase conjugated pulse. The phase conjugated pulse is then transmitted at the target. Processing a target return signal derived from the transmitted phase conjugated pulse enhances the radar cross section of the target because the waveform of the transmitted phase conjugated pulse is matched to the characteristics of the target.

Abstract: In a printed circuit embodiment, dielectric boards in a multilayer arrangement have their ends protruding from a ground plane. Sets of printed dipole elements are disposed along the edge of each board. Each set of dipole elements has three feed ports. Bandpass filters are provided for each feed port. Phase shifters are coupled to each of the feed ports through its respective bandpass filter. At the low band, the outer feed ports are shorted by the filters so that the two sections of dipole elements to the left of the center feed port form one lone band dipole arm, and the two sections of dipole elements to the right of the center feed port form the other low band dipole arm. The low band dipole is driven at the center feed port. At the high band, the center feed port becomes an open circuit so that the two sections to the left thereof form one high band dipole, and the two sections to the right thereof form a second high band dipole. The two outer feed ports drive the dipole array at the high band.

Abstract: A compact, dual series waveguide feed network is disclosed which has application to monopulse radar antennas and is usable in applications requiring compact and light weight feed networks. The network in accordance with the invention uses phase shifters at the phase reversal points of the secondary (42) feed lines to establish a 180.degree. relative phase difference with the corresponding phase reversal point of the primary feed line. No phase shifters are used in the crossguide feed lines (44). Because of the invention's phase shifter arrangement, crossguide lines (44) may be located directly opposite each other instead of being staggered as in prior techniques; hence the size of the network is reduced and resolution is increased. Also, the primary and secondary feed lines may be located closer together because there are no phase shifters with associated matching and transition devices located in the crossguide feed lines.

Abstract: A wideband balanced diplexer splits an incoming wideband microwave frequency signal into separate upper and lower frequency outputs and possesses a sharp band cut-off to increase effective bandwidth. The diplexer includes a pair of waveguide assemblies for separating the upper frequency band from the incoming signal. Each waveguide assembly includes a tuneable, ridged waveguide phase shifter for shifting the phase of the lower frequency band, a reference waveguide for inserting a delay onto the upper frequency signal in order to compensate for the effects of the phase shifter in the other waveguide assembly, and a high pass filter. The high pass filter includes a ridged waveguide having tapered ends of a shape comprising an exponential function raised to a cosine squared power to increase the bandwidth of the upper frequencies and to provide a sharper frequency cut-off.

Abstract: A dual band, phased array antenna especially adaptable for tactical radar capable of performing search, track and identification in a hostile jamming environment. The dual band array antenna is essentially two antennas sharing a common antenna aperture. The two antennas possess separate feed system and beam steering control. Thus, the beams for each frequency band can be steered independently and simultaneously. This design utilizes an ultra-wide band radiating element which can operate over approximately an octave bandwidth encompassing two adjacent microwave bands. In particular, the dual band signals can be received efficiently by the radiating element. A dual band coaxial-to-waveguide transition can be used to carry the signals to a diplexer. The dual band signals are separated at the diplexer and can be processed in separate feed networks.

Abstract: A dual band array antenna is disclosed having interleaved waveguide and dipole arrays, each operating in a different frequency band. The orientation of the waveguides and dipoles is such that polarization of the signals of the two frequency bands is perpendicular to each other, thus reducing mutual coupling. The waveguides are used for the higher frequency band and their cutoff frequency is selected to be above the lower frequency band at which the dipoles operate, in order to reduce mutual coupling into the waveguides. In one embodiment the dipoles are printed on a substrate having a dielectric constant selected so that dipole spacing is the same as the waveguide spacing. This eliminates grating lobe formation in the radiation pattern of the waveguide array. A low pass filter is included in the dipole feed circuit to reject the frequencies at which the waveguides operate.