Abstract: A radio frequency receiver with adaptive dynamic filtering controlled by signals from subsequent or external circuit elements, as required to suppress undesired radio frequency energy, match the radio's input circuit to the received signal, and permit optimized processing of the signal of interest.

Abstract: A family of radio frequency (RF) filter circuits that use radio frequency linear mixers to controllably separate desired frequency spectrum from undesired frequency spectrum, and convert signals from one frequency to another, permitting inclusion in a closed- or open-loop control circuit that supports rapid dynamic manipulation of the filter circuit's center frequency and bandwidth.

Abstract: A radio frequency (RF) mixer is provided. The RF mixer includes two linear-in-the-amplitude-domain RF channels connected in parallel, with each of the two linear-in-the-amplitude-domain RF channels having of an input RF signal applied equally to each channel. Two controllable gain devices are structured to receive the input RF signal. A local oscillator (LO) communicates with both of the controllable gain devices, with one of the controllable gain devices receiving a signal from the LO directly, and the other controllable gain device receiving a signal from the LO after a phase of the LO signal is reversed by a phase inverter. Finally, an output of each of the linear-in-the-amplitude-domain RF channels is combined to form a common intermediate frequency (IF) output.

Abstract: A linear frequency converter or mixer design that utilizes linear time-varying devices and that avoids interaction between the local oscillator (LO) current and other signals inside the mixer, thus achieving high linearity and signal purity. This mixer also uses a LO frequency at least two times lower than conventional mixers, hence improving isolation between different system partitions. This class of mixer may not require a power supply.

Abstract: A sealable cabinet that permits a human or animal to experience a dry bath for carbon dioxide or other gases, with said cabinet fitted with gas, water, and power connections, and a controller to optimize the temperature, gas concentrations, and water vapor content of the interior, plus a switchable means for selecting between a sauna environment and said carbon dioxide bath, with a business method that enables a provider of services involving such equipment to achieve a profitable interface with patients and customers.

Abstract: A sealable cabinet that permits a human or animal to experience a dry bath for carbon dioxide or other gases, with said cabinet fitted with gas, water, and power connections, and a controller to optimize the temperature, gas concentrations, and water vapor content of the interior, plus a switchable means for selecting between a sauna environment and said carbon dioxide bath, with a business method that enables a provider of services involving such equipment to achieve a profitable interface with patients and customers.