Abstract: A mud motor includes a rotor and a stator. Drilling fluid received by cavities of the mud motor drives the rotor to rotate within the stator. The rotor includes one or more rotor lobes extending helically and defining a rotor pitch. The stator includes two or more stator lobes extending helically and defining a stator pitch. The rotor and the stator together define a tapered profile of the mud motor that varies proceeding from a top end of the mud motor to a bottom end of the mud motor. At least one of the rotor pitch or the stator pitch vary as proceeding from the top end of the mud motor to the bottom end of the mud motor.

Abstract: A mud motor includes a rotor and a stator. Drilling fluid received by cavities of the mud motor drives the rotor to rotate within the stator. The rotor includes one or more rotor lobes extending helically and defining a rotor pitch. The stator includes two or more stator lobes extending helically and defining a stator pitch. The rotor and the stator together define a tapered profile of the mud motor that varies proceeding from a top end of the mud motor to a bottom end of the mud motor. At least one of the rotor pitch or the stator pitch vary as proceeding from the top end of the mud motor to the bottom end of the mud motor.

Abstract: A fireplace system can comprise a firebox and a heat exchanger. The heat exchanger may be in fluid communication with ambient air and may comprise an inlet configured to draw air into the front of the heat exchanger. Operation of a fireplace system comprising a heat exchanger may produce airflow through the heat exchanger by natural convection. The airflow through the heat exchanger may reduce heat transmission from the firebox and the fireplace system.

Abstract: A fireplace system can comprise a first safety barrier and a second safety barrier disposed across a firebox opening and defining an interbarrier space. A fireplace system can also comprise a heat exchanger in fluid communication with the interbarrier space. The interbarrier space and heat exchanger may further be in fluid communication with ambient air. Operation of the fireplace system may produce natural convection through the interbarrier space, resulting in cooling of the safety barrier and the fireplace system.

Abstract: A fireplace system can comprise a first safety barrier and a second safety barrier disposed across a firebox opening and defining an interbarrier space. A fireplace system can also comprise a heat exchanger in fluid communication with the interbarrier space. The interbarrier space and heat exchanger may further be in fluid communication with ambient air. Operation of the fireplace system may produce natural convection through the interbarrier space, resulting in cooling of the safety barrier and the fireplace system.

Abstract: Switched-filter duplexing architecture for front-end systems. In some embodiments, a wireless architecture can include a first system having a first signal routing circuit for a first transceiver, and a first antenna node, and be configured to be capable of simultaneous transmit and receive operations for a first band and a receive operation for a second band through the first antenna node. The wireless architecture can further include a second system having a second signal routing circuit for a second transceiver and a second antenna node, and be configured to be capable of a transmit operation for the second band through the second antenna node. The wireless architecture can further include a switchable path implemented to selectively allow the transmit operation for the second band to be performed through the second antenna node of the second system or the first antenna node of the first system.

Abstract: A fireplace system can comprise a firebox and a heat exchanger. The heat exchanger may be in fluid communication with ambient air and may comprise an inlet configured to draw air into the front of the heat exchanger. Operation of a fireplace system comprising a heat exchanger may produce airflow through the heat exchanger by natural convection. The airflow through the heat exchanger may reduce heat transmission from the firebox and the fireplace system.

Abstract: A fireplace system can comprise a firebox and a heat exchanger. The heat exchanger may be in fluid communication with ambient air and may comprise an inlet configured to draw air into the front of the heat exchanger. Operation of a fireplace system comprising a heat exchanger may produce airflow through the heat exchanger by natural convection. The airflow through the heat exchanger may reduce heat transmission from the firebox and the fireplace system.

Abstract: Multiplexing architectures for wireless applications. In some embodiments, a front-end architecture can include a first power amplifier having an output coupled to a transmit filter through a path that is substantially free of a switch. The transmit filter can be configured for a first transmit band or a second transmit band, with the first and second transmit bands at least partially overlapping with each other. The front-end architecture can further include a receive filter configured for at least a first receive band corresponding to the first transmit band, and a second power amplifier having an output capable of being coupled to a first duplexer or a second duplexer through a selector switch. The first duplexer can include a receive portion configured for a second receive band corresponding to the second transmit band.

Abstract: A filtered electromagnetic coupler includes a main transmission line extending between an input port and an output port, and a coupled line section extending between a coupled port and an isolation port. The coupler is configured to couple signal power from the main transmission line to provide coupled signals at the coupled port, and a filter subsystem is connected to the coupled port to filter the coupled signals. The filter subsystem includes filters configured to pass or reject coupled signals by frequency, and the filter subsystem provides the filtered output signal to a measurement node.

Abstract: A filtered electromagnetic coupler includes a main transmission line extending between an input port and an output port, and a coupled line section extending between a coupled port and an isolation port. The coupler is configured to couple signal power from the main transmission line to provide coupled signals at the coupled port, and a filter subsystem is connected to the coupled port to filter the coupled signals. The filter subsystem includes filters configured to pass or reject coupled signals by frequency, and the filter subsystem provides the filtered output signal to a measurement node.

Abstract: A fireplace system can comprise a firebox and a heat exchanger. The heat exchanger may be in fluid communication with ambient air and may comprise an inlet configured to draw air into the front of the heat exchanger. Operation of a fireplace system comprising a heat exchanger may produce airflow through the heat exchanger by natural convection. The airflow through the heat exchanger may reduce heat transmission from the firebox and the fireplace system.

Abstract: A fireplace system can comprise a first safety barrier and a second safety barrier disposed across a firebox opening and defining an interbarrier space. A fireplace system can also comprise a heat exchanger in fluid communication with the interbarrier space. The interbarrier space and heat exchanger may further be in fluid communication with ambient air. Operation of the fireplace system may produce natural convection through the interbarrier space, resulting in cooling of the safety barrier and the fireplace system.

Abstract: A well-logging tool may be positioned within a borehole of a subterranean formation. The well-logging tool may include a housing having an interior defining a dual-detector receiving chamber extending longitudinally, and having first and second portions, and a first azimuthal radiation detector carried by the first portion of the dual-detector receiving chamber. The first azimuthal radiation detector may include a first gamma-ray detector and a first photodetector associated with the first gamma-ray detector. The well-logging tool may include a second spectral radiation detector carried by the second portion of the dual-detector receiving chamber. The second spectral radiation detector may include a second gamma-ray detector and a second photodetector associated with the second gamma-ray detector.

Abstract: A mobile wireless communications device may include an antenna, LTE RF differential inputs, and a front end circuit. The front end circuit may include band pass filters coupled to the antenna, LNAs coupled respectively to the band pass filters, and RF switching circuits. Each RF switching circuit may be respectively coupled between each LNA and a pair of LTE RF differential inputs and configured to switch to one or both of the pair of LTE RF differential inputs.

Abstract: A mobile wireless communications device may include an antenna, primary RF receivers configured to operate at different RF bands, each primary RF receiver having a differential input, and secondary RF receivers also configured to operate at the different RF bands, each secondary RF receiver having a differential input. The mobile wireless communications device may also include first and second RF filters coupled to the antenna and configured to respectively pass first and second RF bands from among the different RF bands, and a first DDPDT RF switch coupled between the first and second RF filters and the differential inputs of respective first ones of the primary and secondary RF receivers.

Abstract: A mobile wireless communications device may include an antenna, primary RF receivers configured to operate at different RF bands, each primary RF receiver having a differential input, and secondary RF receivers also configured to operate at the different RF bands, each secondary RF receiver having a differential input. The mobile wireless communications device may also include first and second RF filters coupled to the antenna and configured to respectively pass first and second RF bands from among the different RF bands, and a first DDPDT RF switch coupled between the first and second RF filters and the differential inputs of respective first ones of the primary and secondary RF receivers.

Abstract: A mobile wireless communications device may include an antenna, LTE RF differential inputs, and a front end circuit. The front end circuit may include band pass filters coupled to the antenna, LNAs coupled respectively to the band pass filters, and RF switching circuits. Each RF switching circuit may be respectively coupled between each LNA and a pair of LTE RF differential inputs and configured to switch to one or both of the pair of LTE RF differential inputs.

Abstract: A mobile wireless communications device may include an antenna, an LTE RF transmitter circuit, and an LTE RF receiver circuit. The mobile wireless communications device may also include band pass filters coupled to the antenna and configured to operate at respective different LTE RF bands, and RF switches coupled respectively between the band pass filters, and the LTE RF cellular transmitter and receiver circuits.