Abstract:
A low temperature radiometer includes a main body, a main cavity, an exit cavity, a suspended thermometer, and an attached thermometer. The main cavity is disposed within the main body and is defined through an off-axis parabolic concentrating cone formed of the inner walls of the main body. The exit cavity is disposed within the main body and is defined through a cylindrical inner surface of the main body. The suspended thermometer is suspended within the exit cavity and is disposed to be in communication with radiation entering the main cavity and being diverted to the exit cavity. The attached thermometer is attached to the outer surface of the main body and is in thermal communication and contact with the main body.
Abstract:
A filtration material comprising a blend of at least two types of fibers: (a) polypropylene fibers and (b) either acrylic or modacrylic fibers. In a preferred embodiment, the blend contains about 50 weight percent polypropylene fibers and about 50 weight percent modacrylic fibers. In another preferred embodiment, the blend contains about 50 weight percent polypropylene fibers and about 50 weight percent acrylic fibers. The fibers can be blended ranging from 90:10 to 10:90 polypropylene to acrylic or modacrylic. At least one type of fibers includes an extractable agent on the outer surfaces thereof. Performance of the blend is superior to the prior art filtration materials, especially at the preferred compositions.
Abstract:
A frequency modulation (FM) radio receiver includes a processing unit that may generate a magnitude value corresponding to a signal strength of each of a plurality of digital samples of a received FM signal. The receiver also includes a noise estimation unit that may filter the magnitude values using a high pass filter and may generate a noise value representative of a noise portion of the received FM signal based upon the filtered magnitude values.
Abstract:
An integrated low-IF (low intermediate frequency) terrestrial broadcast receiver and associated method are disclosed that provide an advantageous and cost-efficient solution. The integrated receiver includes a mixer, local oscillator generation circuitry, low-IF conversion circuitry, and DSP circuitry. And the integrated receiver is particularly suited for small, portable devices and the reception of terrestrial audio broadcasts, such as FM and AM terrestrial audio broadcast, in such portable devices.
Abstract:
A receiver includes a gain stage, a peak detector and a processor. The gain stage provides an output signal, and the peak detector provides a binary indication of whether the output signal has reached a predetermined threshold. The processor controls the gain stage in response to the binary indication.
Abstract:
A radio-frequency (RF) receiver includes a receiver analog circuitry and a receiver digital circuitry. The receiver analog circuitry resides within a first integrated circuit and the receiver digital circuitry resides within a second integrated circuit. The second integrated circuit couples to the first integrated circuit via a one-bit digital interface. The receiver analog circuitry receives an RF signal and processes the received RF signal to generate a digital signal. The receiver analog circuitry provides the digital signal to the receiver digital circuitry. The receiver digital circuitry includes a digital down-converter circuitry that mixes the digital signal with an intermediate frequency (IF) local oscillator (LO) signal to generate a digital down-converted signal. The receiver digital circuitry also includes a digital filter circuitry that filters the digital down-converted signal to generate a filtered digital signal.
Abstract:
A method and apparatus for enhancing signal quality within a wireless receiver are disclosed. An image of a desired signal is down-converted to a baseband signal by a digital down converter. The energy of the baseband signal is subsequently determined. If the energy of the baseband signal is equal to or greater than a predetermined threshold, then the IF is swapped for any incoming signals. If the energy of the baseband signal is less than the predetermined threshold, then the IF is maintained for any incoming signals.
Abstract:
A filter material comprising a blend of at least three types of fibers: (a) polypropylene fibers (b) polymethaphenylene isophtalamide fibers and (c) fibers of a third type selected from the group of acrylic and modacrylic. In a preferred embodiment, the blend contains about ten weight percent polymethaphenylene isophtalamide fibers, about 50 weight percent polypropylene fibers and about 40 weight percent modacrylic fibers. Performance of the blend is superior to the prior art filtration materials, especially at the preferred compositions.
Abstract:
A roofing system having preferred metallic roofing panels overlying a roof structure or a substrate (such as a waterproof membrane) includes a mat of loosely-woven ventilation mesh material between the panels and the roof structure or substrate in order to provide proper ventilation, thus minimizing corrosion resulting from condensed moisture. The mesh is preferably composed of an extruded thermosetting plastic material.
Abstract:
In one aspect, the present invention includes an apparatus having a digital signal processor (DSP), a controller coupled to the DSP to provide control signals to the DSP, and a one-time programmable (OTP) memory coupled to the DSP and the controller. The OTP memory may include multiple code portions including a first code block to control the DSP and a second code block to control the controller.