Abstract: A cylindrical waveguide (1) for analyzing a flowing material (18) using guided microwave spectroscopy (GMS). Spaced apart plates (2, 5) each define a plane within the waveguide housing (3) that is parallel to the direction (47) of material flow through the waveguide. Two opposed frames (7, 19) each surround an aperture (6) that permits access to the region between the waveguide plates (2, 5). A microwave probe assembly (81) is mounted at each frame (7, 19) to permit the radiation and reception of electromagnetic waves within the housing (1). A temperature probe (51) is inserted into the interior of the housing (1) via fitting (13). A y-shaped assembly (89) can be used to divide the flow into two separate paths including a diverter vane (93) that permits flow to be equalized within the two separate flow paths.

Abstract: The present invention includes a guided microwave spectroscopy system (1) that eliminates the need for an automatic gain control feature by providing multiple signal processing paths having differing fixed voltage gains. An emitted signal which exits a test chamber (2) containing a material under test is simultaneously amplified by at least a first fixed gain amplifier (4) and a second fixed gain amplifier (7). The output signal of each amplifier is separately digitized and then normalized for further digital signal processing by a computer (13) in order to determine parameters of the material under test which may have variable microwave radiation characteristics that are a function of the frequency of the signal emitted into the test chamber. During the signal processing step a system clock (121) causes the computer to sample only an integral number of complete output signal cycles.

Abstract: The present invention includes a guided microwave spectroscopy system (1) that eliminates the need for an automatic gain control feature by providing multiple signal processing paths having differing fixed voltage gains. An emitted signal which exits a test chamber (2) containing a material under test is simultaneously amplified by at least a first fixed gain amplifier (4) and a second fixed gain amplifier (7). The output signal of each amplifier is separately digitized and then normalized for further digital signal processing by a computer (13) in order to determine parameters of the material under test which may have variable microwave radiation characteristics that are a function of the frequency of the signal emitted into the test chamber. During the signal processing step a system clock (121) causes the computer to sample only an integral number of complete output signal cycles.

Abstract: A cylindrical waveguide (1) for analyzing a flowing material (18) using guided microwave spectroscopy (GMS). Spaced apart plates (2, 5) each define a plane within the waveguide housing (3) that is parallel to the direction (47) of material flow through the waveguide. Two opposed frames (7, 19) each surround an aperture (6) that permits access to the region between the waveguide plates (2, 5). A microwave probe assembly (81) is mounted at each frame (7, 19) to permit the radiation and reception of electromagnetic waves within the housing (1). A temperature probe (51) is inserted into the interior of the housing (1) via fitting (13). A y-shaped assembly (89) can be used to divide the flow into two separate paths including a diverter vane (93) that permits flow to be equalized within the two separate flow paths.

Abstract: A cylindrical waveguide (1) used for analyzing a flowing stream of corn masa (18) using a guided microwave spectroscopy (GMS) process. The waveguide (1) includes opposed spaced apart plates (2, 5) that each define a plane within the waveguide housing (3) that is parallel to the direction (47) of corn masa flow through the waveguide. The housing (1) includes two opposed frames (7, 19) that each surround an aperture (6) that permits access to the region between the waveguide plates (2, 5). A microwave probe assembly (81) is mounted at each frame (7, 19) to permit the radiation and reception of electromagnetic waves within the housing (1) as required to perform the GMS process. A temperature probe (51) is inserted into the interior of the housing (1) at a fitting (13). In an actual installation a y-shaped assembly (89) can be used to divide the corn masa flow into two separate paths with one path containing the waveguide (1).

Abstract: A cylindrical waveguide (1) used for analyzing a flowing stream of corn masa (18) using a guided microwave spectroscopy (GMS) process. The waveguide (1) includes opposed spaced apart plates (2, 5) that each define a plane within the waveguide housing (3) that is parallel to the direction (47) of corn masa flow through the waveguide. The housing (1) includes two opposed frames (7, 19) that each surround an aperture (6) that permits access to the region between the waveguide plates (2, 5). A microwave probe assembly (81) is mounted at each frame (7, 19) to permit the radiation and reception of electromagnetic waves within the housing (1) as required to perform the GMS process. A temperature probe (51) is inserted into the interior of the housing (1) at a fitting (13). In an actual installation a y-shaped assembly (89) can be used to divide the corn masa flow into two separate paths with one path containing the waveguide (1).

Abstract: Apparatus and methods for profiling atmospheric temperature, water vapor and/or cloud liquid content utilizing passive microwave remote sensing are disclosed. The apparatus includes an antenna for receiving atmospheric microwave emissions having frequencies of interest, a highly stable, tunable frequency synthesizer, and downconverting system receiving selected frequency outputs from the synthesizer and the received emissions and, responsive thereto, providing output signals indicative of the frequencies of interest and representing the profile.

Abstract: This amplifier is equipped with a digital bias control apparatus to provide precise, dynamic control over the operating point of a plurality of amplifying elements in the ampliifer. A processor optimizes the operating point of each individual amplifying element as a function of the amplifying element characteristics, the operating environment and the applied input signal. The use of a processor also enables the user to remotely program the operating point of each individual amplifying element in the amplifier. The processor further enables dynamic changes in the operating characteristics of the amplifier as the operating environment of these amplifing elements changes. The processor also generates an alarm signal if any particular amplifying element is operating out of its nominal specifications. This digital bias control apparatus can function in class A, AB, B or C type of amplifiers whether they are tuned or untuned and whether the amplifier operates in a pulsed or continuous mode.

Abstract: A passive, multi-channel microwave radiometer includes an antenna-lens assembly for receiving, and a first waveguide designed to provide a common path for propagating, 23.8 GHz and 31.4 GHZ atmospheric signals. The 23.8 GHz signal is above the frequency of relative maximum water vapor absorption and the 31.4 GHz signal is near a relative minimum in the water vapor absorption spectrum. Circuitry is responsive to the atmospheric signals for generating output signals representing the respective water vapor and liquid content in and the temperature of the atmosphere. For realtime calibration a blackbody assembly is mounted in the near field of the antenna-lens assembly. The blackbody assembly emits known blackbody microwave signals at 23.8 GHz, 31.4 GHz and in the V band. The radiometer is calibrated during its normal operation by causing a mirror to select the blackbody signals for propagation along the common path.

Abstract: A monitoring system is disclosed that is particularly well suited for use in connection with combustion in a cloud seeding generator. The monitoring system includes an indicator light the energization of which indicates a specific combustion state and normally indicates that combustion has occurred. Energization of the indicator light is controlled by a comparator which has one input connected with a thermocouple positioned in the combustion chamber to monitor the combustion state. The cloud seeding generator is preferably mounted in an aircraft and, when so mounted, the indicator light may be remotely located as, for example, on the aircraft instrument panel to indicate combustion and/or ignition as well as proper operation of the cloud seeding generator.