Abstract: A telemetry system with a matrixed telemetry switch unit array and a method for determining the switch position of a telemetry switch unit. The switch units include steering diodes and parallel signal paths each with unique resistance values. The signal paths correspond to switch positions and are closed when the switch unit is in the corresponding switch position. A signal source is electrically connected to an input current path and output current path of the array with a corresponding telemetry switch unit coupled into the signal path. A plurality of sensing signals are applied through the array and the resultant signals are measured. The switch position is determined from the resultant signals indicating the resistance value of the switch signal path currently coupled into the array signal path while accounting for the voltage drop of the steering diodes.

Abstract: A spectrometer and method for determining an emitted light spectrum. An input light signal is received and directed to an array of interferometers using waveguides. A plurality of self-interfering signals are detected from a first plurality of interferometers in the array of interferometers. The first plurality of interferometers has fewer interferometers than required to satisfy the Nyquist criterion for reconstructing the emitted light spectrum. The emitted light spectrum is reconstructed from the plurality of self-interfering signals using compressive sensing. The plurality of self-interfering signals can provide an interference pattern used to reconstruct the emitted light spectrum. A second plurality of interferometers may output a second plurality of self-interfering signals to reconstruct a low resolution spectrum of the input light signal satisfying the Nyquist criterion. Low resolution signal components can be detected from the low resolution spectrum and used to pre-process the interference pattern.

Abstract: A triple-band bandpass filter with at least one cavity resonator. Each cavity resonator has the same three orthogonal resonances modes corresponding to three unique resonance frequencies. The three unique resonance frequencies define the passbands of the filter. The filter has an input probe coupled to an input cavity resonator. The filter has an output probe coupled to an output cavity resonator. The input and output probes are shaped to concurrently couple signal waveforms in each of the resonance modes. Coupling probes that can be used as input or output probes are also provided. An inter-cavity coupling operable to concurrently transmit signal waveforms in each of the resonance modes is also provided. The inter-cavity coupling can be used to transmit signals between adjacent cavity resonators in the filter.

Abstract: A transmission line circuit assembly has a substrate layer having a transmission line trace, further having a functional portion and a transitional portion. An enclosure of the assembly houses the transitional portion of the transmission line trace. A first surface of a dielectric plug is conductively coupled to an inner top surface of the enclosure. A second surface of the plug is aligned and spaced apart from the transitional portion of the transmission line trace to define a gap therebetween. An interfacing portion of a connecting pin is housed within the enclosure and bonded to the transitional portion. A connecting portion of the pin is connectable to an external conductor. The gap may be filled with a dielectric material. The transitional portion, dielectric plug, dielectric filler and connecting pin form an electromagnetic transition providing tuning and matching of the function portion with the external conductor.

Abstract: A microwave filter has a housing defining an inner cavity. A first resonator is positioned in a first portion of the inner cavity. A second resonator is positioned in a second portion of the inner cavity. A third resonator is positioned in a third portion of the inner cavity. The first resonator and the third resonator are cross-coupled via an iris. The second resonator is elongated and is coupled to the first resonator and the third resonator. The resulting microwave filter has a frequency response having a transmission zero in the lower stopband. A high-pass filter is realized without the use of a cross-coupling probe.

Abstract: A microwave filter has a housing defining an inner cavity. A first resonator is positioned in a first portion of the inner cavity. A second resonator is positioned in a second portion of the inner cavity. A third resonator is positioned in a third portion of the inner cavity. The first resonator and the third resonator are cross-coupled via an iris. The second resonator is elongated and is coupled to the first resonator and the third resonator. The resulting microwave filter has a frequency response having a transmission zero in the lower stopband. A high-pass filter is realized without the use of a cross-coupling probe.

Abstract: Methods and systems for validating positions reported in AIS message signals by fitting suitably chosen functions to signal characteristic data, such as timing and Doppler shift data, derived from a plurality of AIS message signals. Ships whose reported positions deviate from the fitted function may be flagged as suspect.

Abstract: A TE011 cavity filter assembly is disclosed. The system includes at least one resonator operating in TE011 mode having a resonant frequency. The at least one resonator may include a cavity comprising an inner diameter and a cavity length. The at least one resonator may also include a first metal disc inside the cavity. The first metal disc may include a disc diameter and a void in the metal disc, which includes a void diameter and a void depth. The inner diameter of the cavity may be greater than the disc diameter creating a gap with a gap width and a gap depth. The TE011 cavity filter assembly may further include positive coupling.

Abstract: A method of extracting automatic identification system (AIS) message segments from AIS signals received by a satellite. The method includes: (a) receiving AIS signals from satellite antennas; (b) generating multiple versions of the AIS signals; (c) extracting message segments contained within each of the AIS signals using one or more AIS receivers; (d) sorting the message segments by time; and (e) deleting any duplicate message segments. Multiple versions of the AIS signals may be generated by one or more of the following methods: (i) processing the AIS signals multiple times, each time with different AIS receiver parameter settings; (ii) splitting each signal into multiple signals and filtering each of the multiple signals separately; (iii) receiving multiple AIS signals and combining them with different phases and amplitudes to produce a plurality of combined AIS signals; and (iv) removing extracted message segments from the received AIS signals and reprocessing the modified AIS signals.

Abstract: A microwave cavity filter is configured for operation in the dual TE22N mode to realize a very high Q factor at very high frequency ranges. The microwave filter is formed from using one or more cylindrical cavities in which two orthogonal field polarizations of the TE22N mode are excited and coupled together by means of a coupling element. Different combinations of inter-cavity irises provide for both direct and cross-coupling of aligned field polarizations in adjacent cavities, as required, to realize complex filter functions. The irises may be formed in either a side or end wall of the cavities for both collinear and planar mount configuration. Negative mode coupling also allows for transmission zeros to be realized on either side of the filter passband.

Abstract: A resonator cavity for supporting a plurality of resonant modes and filtering electromagnetic energy includes a cavity and a resonator element with a mounting flange. The cavity is defined by a top end wall, a bottom end wall and a sidewall and has a longitudinal axis along its length is defined. The resonator element is positioned within the cavity along the longitudinal axis and includes a mounting flange. The resonator element is only in physical contact with the cavity through the mounting flange at a mounting location and where at least one resonant mode of the electromagnetic energy exhibits a local minimum. The dimensions of the cavity and the resonator element are selected so that the associated electromagnetic energy is defined by an electromagnetic field pattern that substantially repeats itself at least twice along the length of the resonator.

Abstract: Various embodiments are described herein for a system and method of detecting Automatic Identification System (AIS) signals in space and decoding these signals. In one aspect, a system for performing this function is described which includes a receiver configured to receive the plurality of AIS signals and pre-process the plurality of AIS signals to produce digital input data, and a processing unit configured to process the digital input data to identify one or more candidate AIS message signals based on Doppler offsets associated with the digital input data, determine corresponding Doppler offset estimates and time estimates of the one or more candidate AIS message signals, decode the one or more candidate AIS message signals to obtain corresponding message segments and validate the decoded message segments for proper AIS formatting.

Abstract: Novel quadruple-mode, dual-mode, and dual-band filters as well multiplexers are presented. A cylindrical dielectric resonator sized appropriately in terms of its diameter D and length L will operate as a quadruple-mode resonator, offering significant size reduction for dielectric resonator filter applications. This is achieved by having two mode pairs of the structure resonate at the same frequency. Single-cavity, quad-mode filters and higher order 4n-pole filters are realizable using this quad-mode cylindrical resonator. The structure of the quad-mode cylinder can be simplified by cutting lengthwise along its central axis to produce a half-cut cylinder suitable for operation in either a dual-mode or a dual-band. Dual-mode, 2n-pole filters are realizable using this half-cut cylinder. Dual-band filters and diplexers are further realizable using the half-cut structure and full cylinder by carrying separate frequency bands on different resonant modes of the structure.

Abstract: An inline microwave bandpass filter where cross coupling between non-adjacent resonators is realized by changing the orientation of selected resonators. The microwave bandpass filter includes a cavity and three or more resonators arranged in a row (or inline) in the cavity. At least one resonator has a different spatial orientation from at least one other resonator. For example, one or more of the resonators may be rotated 90 or 180 degrees with respect to one of the other resonators. This arrangement of resonators facilitates sequential coupling between pairs of adjacent resonators and cross coupling between at least one pair of non-adjacent resonators without the use of additional cross coupling structures such as dedicated coupling probes or extra cavities. One or more plates may be introduced between adjacent resonators to independently control the sequential and cross coupling.

Abstract: A resonator cavity for supporting a plurality of resonant modes and filtering electromagnetic energy includes a cavity and a resonator element with a mounting flange. The cavity is defined by a top end wall, a bottom end wall and a sidewall and has a longitudinal axis along its length is defined. The resonator element is positioned within the cavity along the longitudinal axis and includes a mounting flange. The resonator element is only in physical contact with the cavity through the mounting flange at a mounting location and where at least one resonant mode of the electromagnetic energy exhibits a local minimum. The dimensions of the cavity and the resonator element are selected so that the associated electromagnetic energy is defined by an electromagnetic field pattern that substantially repeats itself at least twice along the length of the resonator.

Abstract: Embodiments disclosed herein relate generally to digital transponders.

Abstract: A resonator cavity for supporting a plurality of resonant modes and filtering electromagnetic energy includes a cavity and a resonator element with a mounting flange. The cavity is defined by a top end wall, a bottom end wall and a sidewall and has a longitudinal axis along its length is defined. The resonator element is positioned within the cavity along the longitudinal axis and includes a mounting flange. The resonator element is only in physical contact with the cavity through the mounting flange at a mounting location and where at least one resonant mode of the electromagnetic energy exhibits a local minima. The dimensions of the cavity and the resonator element are selected so that the associated electromagnetic energy is defined by an electromagnetic field pattern that substantially repeats itself at least twice along the length of the resonator.

Abstract: An optical broadband micro-spectrometer containing an input optical assembly, a group of slab waveguide spatial heterodyne spectrometer (SHS) integrated circuits (ICs), a detection module and a processor for multi-line detection. The input optical assembly applies an input light signal uniformly with respect to brightness and frequency to the apertures of the waveguides and may project a pupil image onto the SHS input face and may be a scanner. Each slab waveguide spatial heterodyne spectrometer (SHS) integrated circuit (IC) contains at least one slab waveguide SHS IC. The detection module bonds directly to the slab waveguide output apertures. Each slab waveguide SHS IC may contain one or more slab waveguide SHS.

Abstract: Various embodiments are described herein for a system and method of detecting Automatic Identification System (AIS) signals in space and decoding these signals. In one aspect, a system for performing this function is described which includes a receiver configured to receive the plurality of AIS signals and pre-process the plurality of AIS signals to produce digital input data, and a processing unit configured to process the digital input data to identify one or more candidate AIS message signals based on Doppler offsets associated with the digital input data, determine corresponding Doppler offset estimates and time estimates of the one or more candidate AIS message signals, decode the one or more candidate AIS message signals to obtain corresponding message segments and validate the decoded message segments for proper AIS formatting.

Abstract: Various embodiments are described of an antenna including a common ground plane, a first set of N approximately resonant elements with a length I2 and a second set of M approximately resonant elements with a length I1. The first set of N approximately resonant elements are wound to form a first helix with an initial diameter d2 and a height h2. The second set of M approximately resonant elements are wound in the opposite direction to the first set of N approximately resonant elements to form a second helix. The second helix is centrally disposed within the first helix, and d1 is less than d2 and h1 is greater than h2.